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Objectives The primary objective is to evaluate the efficacy of camostat to prevent respiratory deterioration in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Secondary objectives include assessment of the ability of camostat to reduce the requirement for Coronavirus disease 2019 (COVID-19) related hospital admission and to reduce the requirement for supplementary oxygen and ventilation as treatment for SARS-CoV-2 infection, to evaluate overall mortality related to COVID-19 and to evaluate the efficacy of camostat by effect on clinical improvement. Research objectives include to assess change in COVID-19 symptom severity, to evaluate the ability of camostat to reduce viral load throughout duration of illness as well as translational research on host and viral genomics, serum antibody production, COVID-19 diagnostics, and validation of laboratory testing methods and biomarkers. Trial design SPIKE-1 is a randomised, multicentre, prospective, open label, community-based clinical trial. Eligible patients will be randomised 1:1 to the camostat treatment arm and control arm (best supportive care). The trial is designed to include a pilot phase recruiting up to 50 patients in each arm. An initial review at the end of the pilot phase will allow assessment of available data and inform the requirement for any protocol adaptations to include refinement of eligibility criteria to enrich the patient population and sample size calculations. Up to 289 additional patients will be randomised in the continuation phase of the trial. A formal interim analysis will be performed once 50% of the maximum sample size has been recruited Participants The trial will recruit adults (≥ 18 years) who score moderate to very high risk according to COVID-age risk calculation, with typical symptoms of COVID-19 infection as per Public Health England guidance or equivalent organisations in the UK, Health Protection Scotland, Public Health Wales, Public Health Agency (Northern Ireland) and with evidence of current COVID-19 infection from a validated assay. The trial is being conducted in the UK and patients are recruited through primary care and hospital settings. Intervention and comparator Eligible patients with be randomised to receive either camostat tablets, 200 mg four times daily (qds) for 14 days (treatment arm) or best supportive care (control arm). Main outcomes Primary outcome measure: the rate of hospital admissions requiring supplemental oxygen. Secondary outcome measures include: the rate of COVID-19 related hospital admission in patients with SARS-CoV-2 infection; the number of supplementary oxygen-free days and ventilator-free days measured at 28 days from randomisation; the rate of mortality related to COVID-19 one year from randomisation; the time to worst point on the nine-point category ordinal scale (recommended by the World Health Organization: Coronavirus disease (COVID-2019)) or deterioration of two points or more, within 28 days from randomisation. Research outcomes include the assessment of change in COVID-19 symptom severity on days 1-14 as measured by (1) time to apyrexia (maintained for 48 hrs) by daily self-assessment of temperature, time to improvement (by two points) in peripheral oxygenation saturation defined by daily self-assessment of fingertip peripheral oxygenation saturation levels, (3) assessment of COVID-19 symptoms using the Flu-iiQ questionnaire (determined by app recording and/or daily video call (or phone) consultation and (4) assessment of functional score (where possible) at screening, day 7 and 14. The ability of camostat to reduce viral load throughout duration of illness will be assessed by (1) change in respiratory (oropharyngeal/nasopharyngeal swab RT-PCR) log10 viral load from baseline to Days 7 and 14, (2) change in respiratory (saliva RT-PCR) log10 viral load from baseline to Days 1-14 and (3) change in upper respiratory viral shedding at Day 1 -14 measured as time to clearance of nasal SARS-CoV-2, defined as 2 consecutive negative swabs by qPCR. Additional translational research outcomes include assessment of host and viral genomics, serum antibody production and COVID-19 diagnostics at baseline and on Days 7 and 14. Randomisation Eligible patients will be randomised using an interactive web response system (IWRS) in a 1:1 ratio to one of two arms: (1) treatment arm or (2) control arm. Blinding (masking) The trial is open-label. Numbers to be randomised (sample size) The trial is designed to include a pilot and a continuation phase. Up to 100 patients (randomised 1:1 treatment and control arm) will be recruited in the pilot phase and a maximum of 289 patients (randomised 1:1 treatment and control) will be recruited as part of the continuation phase. The total number of patients recruited will not exceed 389. Trial Status Protocol version number v3 25 September 2020. Trial opened to recruitment on 04 August 2020. The authors anticipate recruitment to be completed by October 2021. Trial registration EudraCT 2020-002110-41; 18 June 2020 ClinicalTrials.gov NCT04455815; 02 July 2020 Full protocol The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). Unpublished PK data provided under confidentiality agreement to the trial Sponsor has been removed from the background section of the protocol to allow for publication of the trial protocol. In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Background: The pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). COVID-19 may take a severe course, resulting in sepsis, and antivirals are urgently needed to combat the disease. However, at present, only drugs developed against other diseases are available including the Malaria drug hydroxychloroquine but their therapeutic efficacy is unclear. Camostat mesylate, a clinically-proven protease inhibitor for treatment of pancreatitis, was shown to block SARS-CoV-2 entry into lung cells. Whether camostat mesylate dampens COVID-19 induced sepsis and the associated organ failure is unknown. Here we compare clinical courses of critically ill COVID-19 patients treated with either camostat mesylate or hydroxychloroquine. Methods: Eleven COVID-19 patients with organ failure were treated in intensive care unit (ICU) at our institution. Five patients (group 1) received hydroxychloroquine and six patients (group 2) camostat mesylate. Clinical disease status was assessed by Simplified Acute Physiology Score (SAPS) II and Sequential/ Sepsis-related Organ Failure Assessment (SOFA) score at day 1, 3 and 8. Viral load was determined from nasopharyngeal swabs. Findings: Patient age ranged from 45 to 76 years, all but one had histories of chronic disease and cardiovascular risk factors. Median symptomatic period was 2-10 days before being transferred to ICU. No differences in SAPS II scores or SOFA scores were observed upon ICU admission. In group 1, SOFA and SAPS II scores remained elevated (2 patients died) while in group 2 SOFA and SAPS II score decreased from 9 to 4 points (1 patient died). The decline in disease severity for group 2 was paralleled by a decline in inflammatory markers, which was not observed in group 1. The virus load in the nasopharynx was variable between patients, did not correlate with organ failure and no marked differences were observed between groups 1 and 2. Interpretation: The severity of COVID-19 sepsis markedly decreased upon camostat mesylate treatment within a period of 8 days and a similar effect was not observed upon hydroxychloroquine treatment. Camostat mesylate thus warrants further evaluation within randomized clinical studies. Funding Statement: Authors were employed at the University of Gottingen or at the Infection Biology Unit of the German Primate Center (Leibniz Institute for Primate Research). All expenses were covered by publicly funded institutions. Stefan Pohlmann received funding from the German Federal Ministry of Education and Research (BMBF), RAPID Fund (#01KI1723D). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: Compassionate use was approved by our local ethical committee at the University of Gottingen.

Background Chronic pancreatitis (CP) is a progressive, fibro-inflammatory disease characterized by enzymatic autoactivation and subsequent fibrotic replacement of acinar cells. A significant proportion of patients develop pain, which may be due to many causes, including perineural inflammation, altered central processing of pain signals, parenchymal structural changes, and ductal obstruction. Currently there are no approved medical treatment options for CP-associated pain. NI-03 (camostat mesilate) is an orally administered serine protease inhibitor that reduces pancreatic enzyme activity and has been widely used for the treatment of CP-associated pain in Japan. The current study will assess the safety and efficacy of NI-03 for reduction of CP-associated pain in the USA. Methods The current study consists of two phases. First, a phase I study will be performed to establish the pharmacokinetics and safety profile over a 1-week period following a single dose (100, 200, or 300 mg). Subsequently, a phase II study will be performed consisting of a double-blind, randomized, controlled trial (RCT). This RCT will evaluate the efficacy of each of the three doses of NI-03 given three times daily compared to placebo over 28 days. A 7-day, single-blind, run-in period will precede the double-blind phase to assess baseline pain characteristics. The primary efficacy outcome is the average of worst daily pain scores (numeric rating scale of 0–10) over the terminal 7 days of the study period compared to baseline. Secondary efficacy outcomes include change in opioid dose and quality of life measures, and time to first rescue intravenous analgesic. Adverse events will be recorded. Discussion NI-03 has been used successfully and safely in Japan to treat CP-associated pain. The aim of the current study is to assess the safety and efficacy of NI-03 using a rigorous RCT in a population in the USA. This study may fill an important clinical gap to provide an effective medical treatment option for CP-associated pain. Trial registration ClinicalTrials.gov, NCT02693093. Registered through the National Institutes of Health on 26 February 2016. Electronic supplementary material The online version of this article (10.1186/s13063-019-3606-y) contains supplementary material, which is available to authorized users.

Trypsin is the major serine protease responsible for intestinal protein digestion. An inhibitor, camostat (CS), reduced weight gain, hyperglycemia, and dyslipidemia in obese rats; however, the mechanisms for these are largely unknown. We reasoned that CS creates an apparent dietary protein restriction, which is known to increase hepatic fibroblast growth factor 21 (FGF21). Therefore, metabolic responses to CS and a gut-restricted CS metabolite, FOY-251, were measured in mice. Food intake, body weight, blood glucose, branched-chain amino acids (LC/MS), hormone levels (ELISA), liver pathology (histology), and transcriptional changes (qRT-PCR) were measured in ob/ob, lean and diet-induced obese (DIO) C57BL/6 mice. In ob/ob mice, CS in chow (9–69 mg/kg) or FOY-251 (46 mg/kg) reduced food intake and body weight gain to a similar extent as pair-fed mice. CS decreased blood glucose, liver weight, and lipidosis and increased FGF21 gene transcription and plasma levels. In lean mice, CS increased liver FGF21 mRNA and plasma levels. Relative to pair feeding, FOY-251 also increased plasma FGF21 and induced liver FGF21 and integrated stress response (ISR) transcription. In DIO mice, FOY-251 (100 mg/kg po) did not alter peak glucose levels but reduced the AUC of the glucose excursion in response to an oral glucose challenge. FOY-251 increased plasma FGF21 levels. In addition to previously reported satiety-dependent (cholecystokinin-mediated) actions, intestinal trypsin inhibition engages non-satiety-related pathways in both leptin-deficient and DIO mice. This novel mechanism improves metabolism by a liver-integrated stress response and increased FGF21 expression levels in mice. NEW & NOTEWORTHY Trypsin inhibitors, including plant-based consumer products, have long been associated with metabolic improvements. Studies in the 1980s and 1990s suggested this was due to satiety hormones and caloric wasting by loss of protein and fatty acids in feces. This work suggests an entirely new mechanism based on the lower amounts of digested protein available in the gut. This apparent protein reduction may cause beneficial metabolic adaptation by the intestinal-liver axis to perceived nutrient stress.

Background: The trans-membrane protease serine 2 (TMPRSS2) is essential for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cell entry and infection. Efficacy and safety of TMPRSS2 inhibitors in patients with coronavirus disease 2019 (Covid-19) have not been evaluated in randomized trials.Methods: We conducted an investigator-initiated, double-blind, randomized, placebo-controlled multicenter trial in patients hospitalized with confirmed SARS-CoV-2 infection from April 4, to December 31, 2020. Within 48 h of admission, participants were randomly assigned in a 2:1 ratio to receive the TMPRSS2 inhibitor camostat mesilate 200 mg three times daily for 5 days or placebo. The primary outcome was time to discharge or clinical improvement measured as ≥2 points improvement on a 7-point ordinal scale. Other outcomes included 30-day mortality, safety and change in oropharyngeal viral load.Findings: 137 patients were assigned to receive camostat mesilate and 68 to placebo. Median time to clinical improvement was 5 days (interquartile range [IQR], 3 to 7) in the camostat group and 5 days (IQR, 2 to 10) in the placebo group ( P = 0·31). The hazard ratio for 30-day mortality in the camostat compared with the placebo group was 0·82 (95% confidence interval [CI], 0·24 to 2·79; P = 0·75). The frequency of adverse events was similar in the two groups. Median change in viral load from baseline to day 5 in the camostat group was -0·22 log 10 copies/mL ( p Interpretation: Under this protocol, camostat mesilate treatment was not associated with increased adverse events during hospitalization for Covid-19 and did not affect time to clinical improvement, progression to ICU admission or mortality. ClinicalTrials.gov Identifier: NCT04321096. EudraCT Number: 2020-001200-42.

Camostat mesilate is in widespread clinical use mainly to treat chronic pancreatitis, and drug-induced lung injury has not been previously reported. However, pulmonary infiltration with peripheral blood eosinophilia appeared after taking camostat mesilate for ten days. The histological findings showed eosinophilic infiltration into the alveolar space and interstitum, and drug lymphocyte stimulation test of peripheral blood was positive. Both peripheral blood eosinophilia and pulmonary involvements improved two weeks later with the cessation of this drug. To the best of our knowledge, this case is the first report of camostat mesilate-induced acute eosinophilic pneumonia.

Many studies clearly demonstrate inhibition of dietary fat preference by exogenous enterostatins in rodents. However, what role endogenous enterostatin, if any, may play in the regulation of fat intake is not clear. To this end, we examined whether there is a relationship between plasma enterostatin (VPDPR)-like immunoreactivity and fat preference. Additionally, since enterostatin is a product of tryptic cleavage of procolipase, we examined the effect of camostat, a protease inhibitor known to inhibit trypsin and other proteases, on dietary fat preference and plasma enterostatin concentration. The results of these studies show that while there was a significant inverse relationship between plasma enterostatin and fat preference, the effect of camostat on fat preference or plasma enterostatin concentration was not clear.

We have shown that vagotomy (VGX) attenuates the reduction of meal size (MS) produced by cholecystokinin (CCK) -8 and -33 and that celiaco-mesenteric ganglionectomy (CMGX) attenuates the prolongation of the intermeal interval (IMI) produced by CCK-33. Here, we report the following novel data. First, by determining the distribution of CCK 1 receptor messenger RNA, which mediates reduction of MS and prolongation of IMI by CCK, in seven regions of the gastrointestinal tract in the adult rat we found that the duodenum contains the highest concentration of this receptor in the gut. Second, based on the previous finding we performed a unique surgical technique known as duodenal myotomy (MYO), which severs all the nerves of the gut wall in the duodenum including vagus, splanchnic and enteric nerves. Third, we determined MS and IMI in duodenal MYO rats in responses to endogenous CCK-58 released by the non-nutrient, trypsin inhibitor, camostat and CCK-8 to test the possibility that the duodenum is the site of action for reduction of MS and prolongation of IMI. We found that, similar to the previous work reported by using CCK-8 and MS, duodenal MYO also blocked reduction of MS by camostat. Forth, duodenal MYO blocked prolongation of IMI by camostat. As such, our current results suggest that the duodenum is the gut site that communicates both feeding signals of endogenous CCK, MS and IMI, with the brain through vagal and splanchnic afferents.

Camostat mesilate (or mesylate) releases endogenous cholecystokinin (CCK) or CCK-58, the only detectable endocrine form of CCK in the rat, and reduces cumulative food intake by activating CCK(1) receptor. However, the literature lacks meal pattern analysis and an appropriate dose-response curve for this peptide. Therefore, the current study determines meal size (MS), intermeal interval (IMI) and satiety ratio (SR) by orogastric gavage of camostat (0, 12.5, 25, 50, 100, 200, 300, 400, 800mg/kg) and compares them to those previously reported by a single dose of CCK-8 (1nmol/kg, i.p), the most utilized form of CCK. We found that camostat (200, 300, 400 and 800mg/kg) and CCK-8 reduced cumulative food intake and the size of the first meal, but only camostat prolonged IMI and increased SR. There was no change in the duration of the first two meals or in rated behaviors such as feeding, grooming, standing and resting in response to camostat and CCK-8, but there was more resting during the IMI in response to camostat. This study provides meal pattern analysis and an appropriate dose-response curve for camostat and CCK-8. Camostat reduces food intake by decreasing MS and prolonging IMI, whereas CCK-8 reduces food intake by reducing only meal size.

Inhibition of airway epithelial sodium channel (ENaC) function enhances mucociliary clearance (MCC). ENaC is positively regulated by channel-activating proteases (CAPs), and CAP inhibitors are therefore predicted to be beneficial in diseases associated with impaired MCC. The aims of the present study were to 1) identify low-molecular-weight inhibitors of airway CAPs and 2) to establish whether such CAP inhibitors would translate into a negative regulation of ENaC function in vivo, with a consequent enhancement of MCC. To this end, camostat, a trypsin-like protease inhibitor, provided a potent (IC(50) approximately 50 nM) and prolonged attenuation of ENaC function in human airway epithelial cell models that was reversible upon the addition of excess trypsin. In primary human bronchial epithelial cells, a potency order of placental bikunin > camostat > 4-guanidinobenzoic acid 4-carboxymethyl-phenyl ester > aprotinin >> soybean trypsin inhibitor = alpha1-antitrypsin, was largely consistent with that observed for inhibition of prostasin, a molecular candidate for the airway CAP. In vivo, topical airway administration of camostat induced a potent and prolonged attenuation of ENaC activity in the guinea pig trachea (ED(50) = 3 microg/kg). When administered by aerosol inhalation in conscious sheep, camostat enhanced MCC out to at least 5 h after inhaled dosing. In summary, camostat attenuates ENaC function and enhances MCC, providing an opportunity for this approach toward the negative regulation of ENaC function to be tested therapeutically.

In the clinical setting,the frequency of adverse effects is directly linked to treatment results but during chemotherapy,they are unavoidable.One of them is stomatitis,a distressing toxic effect.In patients receiving myelosuppressive chemotherapy for solid tumors,the prevalence of stomatitis is 5-40% while its prevalence in patients receiving stem cell transplantation is 75-100%.Stomatitis-associated pain is the main source of cancer treatment-related pain and in some patients it is so severe that narcotic analgesia is required.Oxidative stress may also be associated with chemotherapy-induced stomatitis and a mouthwash containing allopurinol,rebamipide and camostat for the removal of free radicals is widely used for the prevention and treatment of such stomatitis.However,such agents are not covered by the Japanese National Health Insurance scheme and there is little scientific evidence for their antioxidative properties and effectiveness in the prevention and treatment of chemotherapy-induced stomatitis.We therefore attempted to establish a more useful mouthwash.In the first part of this study,we investigated the antioxidant properties of various compounds.We then used H2O2-induced HO-1-N-1 cell injury as a model of stomatitis and found that epigallocatechin gallate had a strong preventive effect against it.Epigallocatechin gallate would therefore be a good component of a mouthwash for the prevention of stomatitis in patients undergoing cancer chemotherapy.

Objective To investigate the effects of Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat on rat spontaneous chronic pancreatitis and the pathological relationships between formulas and syndromes. Methods Fifty-seven male WBN/Kob rats at age of 4 weeks were divided into five groups: untreated group (n=18), Guizhi Decoction-treated group (n=9), Chaihu Guizhi Decoction-treated group (n=9), Xiaochaihu Decoction-treated group (n=9) and camostat-treated group (n=12). The rats in each group were fed with corresponding drugs for 12 weeks. The pancreatic wet weight and histopathological changes of pancreatic tissue were observed every four weeks. Meanwhile, the expression level of pancreatitis-associated protein (PAP) in pancreas was detected by RT-PCR technique and immunohistochemical method. Results In the untreated group, the histopathological changes in pancreas were observed in rats at 12-week age, while such changes were absent in the Guizhi Decoction-treated group. The histopathological changes in pancreas were quite remarkable in rats at 16-week age in both the Xiaochaihu Decoction-treated and the camostat-treated groups. The expression level of PAP mRNA was lower in the Guizhi Decoction-treated group than those in the other groups. The PAP expressions were absent in rats at 12-week age in the Guizhi Decoction-treated and the Chaihu Guizhi Decocion-treated groups. Conclusion Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat are all beneficial to prevention and cure of chronic pancreatitis, and Guizhi Decoction is the most effective one. It is speculated that Taiyang exterior syndrome may be the pathogenesis of basic syndrome may be the pathogenesis of basic syndrome of spontaneous chronic pancreatitis, and the expression of PAP may be its pathological basis.

Cholecystokinin (CCK)-induced pancreatic growth in mice involves parallel increases in DNA and protein. The mammalian target of rapamycin (mTOR) signalling pathway regulates mRNA translation and its activation is implicated in growth of various tissues. The aim of this study was to elucidate whether mTOR activation is required for pancreatic growth in a mouse model of increased endogenous CCK release. In mice fed chow containing the synthetic protease inhibitor camostat, protein synthetic rates and phosphorylation of two downstream targets of mTOR, eukaryotic initiation factor 4E binding protein 1 (4E-BP1) and the ribosomal protein S6 (S6), increased in comparison with fasted controls. The camostat-induced increases in protein synthesis and 4E-BP1 and S6 phosphorylation were almost totally abolished by administration of the mTOR inhibitor rapamycin 1 h prior to camostat feeding. In contrast, the phosphorylation of ERK1/2 and JNK and the expression of the early response genes c-jun, c-fos, ATF3 and egr-1 induced by camostat feeding were not affected by rapamycin. In mice fed camostat for 7 days, the ratio of pancreatic to body weight increased by 143%, but when rapamycin was administered daily this was reduced to a 22% increase. Changes in pancreatic mass were paralleled by protein and DNA content following camostat feeding and rapamycin administration. Moreover, while BrdU incorporation, an indicator of DNA synthesis, was increased to 448% of control values after 2 days of camostat feeding, rapamycin administration completely inhibited this increase. We conclude that the mTOR signalling pathway is required for CCK-induced cell division and pancreatic growth.

OBJECTIVES Prior studies have indicated that endogenous or exogenous cholecystokinin (CCK) induces transient acinar cell proliferation at about 24 hours after its stimulation. The aims of the present study were to determine the time point when the administration of the CCK-A-receptor antagonist loxiglumide had its maximal suppressive effect on the proliferation of pancreatic acinar cells and to investigate the effects of loxiglumide on the cell cycle time of pancreatic acinar cells during transient acinar cell proliferation induced by endogenous or exogenous CCK. METHODS Eight-week-old Wistar rats were divided into the following groups: preadministration of loxiglumide (40 mg/kg) intravenously at 120, 60, and 0 minutes before endogenous CCK stimulation induced by a single oral administration of camostat (50 mg/kg) or exogenous CCK stimulation by a subcutaneous injection of CCK-8 (6 g/kg body weight). For the controls, intravenous saline was used instead of loxiglumide (n = 7 in each group). The proliferative activity of pancreatic acinar cells at 24 hours after CCK stimulation and the cell cycle time of these proliferating pancreatic acinar cells were studied using an immunohistochemical technique. RESULTS The most significant suppression of the proliferation of the acinar cells was observed in those groups which received loxiglumide 60 minutes before CCK stimulation (P < 0.016), but preadministration of loxiglumide had no effect on the cell cycle time of the proliferating acinar cells (not significant). CONCLUSION CCK antagonist loxiglumide is expected as an excellent clinical applicable agent for acute pancreatitis. Previous researches suggest that CCK is an aggravating factor during the acute phase of acute pancreatitis, but CCK may be a healing factor during the recovery period. From the results of the present study, it can be said that the excess chronic administration of CCK antagonists during the acute phase of acute pancreatitis may prevent any regrowth of pancreatic cells during the healing period of acute pancreatitis.

The pathogenesis of reflux esophagitis is not well understood and remains controversial. Distal gastrectomy serves as a model to assess the role of duodenal reflux with low gastric acidity in the development of reflux esophagitis. We investigated the clinical usefulness and antitrypsin activity after treatment with a trypsin inhibitor, camostat mesilate, against the reflux esophagitis after distal gastrectomy reconstructed with Billroth-I anastomosis.Twenty-eight patients with gastroesophageal reflux disease after distal gastrectomy were prescreened according to esophageal pH level and trypsin activity, and consequently 11 patients were enrolled in the present clinical study. Esophageal and duodenal washings were aspirated for the evaluation of the pretreatment trypsin activity. Then 100 mg of camostat mesilate was administered orally. At 30 and 120 minutes after the administration, duodenal washings were aspirated for the evaluation of posttreatment trypsin activity. Thereafter, 300 mg of camostat mesilate was administered orally 3 times daily for a 4-week period. On the 28th day of administration, the grade of reflux esophagitis (Los Angeles classification) was re-evaluated under endoscopy and the esophageal washings were aspirated for the evaluation of trypsin activity.The trypsin activities in the duodenum both at 30 and 120 minutes after oral ingestion of camostat mesilate were decreased significantly in comparison with those in the pretreatment period in each patient (P.001). In 6 of 7 patients with detectable trypsin activity in the esophagus, the activities after the 28th day of treatment were lower than those in the pretreatment period, and the symptoms were milder than those before treatment (P.05). Furthermore, endoscopic evaluation showed that 40% of patients were grade B, C, and D after treatment (28th day), whereas 70% of patients were grade B, C, and D before the treatment.Oral administration of trypsin inhibitor can improve reflux esophagitis after distal gastrectomy concomitant with decreased trypsin activity.

Camostat mesilate (CM), an oral protease inhibitor, has been used clinically for the treatment of chronic pancreatitis in Japan. However, the mechanism by which it operates has not been fully understood. Our aim was to evaluate the therapeutic efficacy of CM in the experimental pancreatic fibrosis model induced by dibutyltin dichloride (DBTC), and we also determined the effect of CM on isolated monocytes and panceatic stellate cells (PSCs). In vivo, chronic pancreatitis was induced in male Lewis rats by single administration of 7 mg/kg DBTC and a special diet containing 1 mg/g CM was fed to the DBTC+CM-treated group from day 7, while the DBTC-treated group rats were fed a standard diet. At days 0, 7, 14 and 28, the severity of pancreatitis and fibrosis was examined histologically and enzymologically in both groups. In vitro, monocytes were isolated from the spleen of a Lewis rat, and activated with lipopolysaccharide stimulation. Thereafter, the effect of CM on monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) production from monocytes was examined. Subsequently, cultured rat PSCs were exposed to CM and tested to see whether their proliferation, MCP-1 production and procollagen alpha1 messenger RNA expression was influenced by CM. In vivo, the oral administration of CM inhibited inflammation, cytokines expression and fibrosis in the pancreas. The in vitro study revealed that CM inhibited both MCP-1 and TNF-alpha production from monocytes, and proliferation and MCP-1 production from PSCs. However, procollagen alpha1 expression in PSCs was not influenced by CM. These results suggest that CM attenuated DBTC-induced rat pancreatic fibrosis via inhibition of monocytes and PSCs activity.

CCK acts on pancreatic acinar cells to increase intracellular Ca2+leading to secretion of digestive enzymes and, in the long term, pancreatic growth. Calcineurin (CN) is a serine/threonine-specific protein phosphatase activated by Ca2+and calmodulin that recently has been shown to participate in the growth regulation of cardiac and skeletal myocytes. We therefore tested the effect of two different CN inhibitors, cyclosporine A (CsA) and FK506, on mouse pancreatic growth induced by oral administration of the synthetic protease inhibitor camostat, a known stimulator of endogenous CCK release. Mice were fed a powdered diet with or without 0.1% camostat. Pancreatic wet weight, protein, and DNA were increased in response to camostat in a time-dependent manner over 10 days in ICR mice but not in CCK-deficient mice. Both CsA (15 mg/kg) and FK506 (3 mg/kg) given twice daily blocked the increase in pancreatic wet weight and protein and DNA content induced by camostat. The increase in plasma CCK induced by camostat was not blocked by CsA or FK506. Camostat feeding also increased the relative amount of CN protein, whereas levels of MAPKs, ERKs, and p38 were not altered. In summary, 1) CCK released by chronic camostat feeding induces pancreatic growth in mice; 2) this growth is blocked by treatment with both CsA and FK506, indicating a role for CN; 3) CCK stimulation also increases CN protein. In conclusion, activation and possibly upregulation of CN may participate in regulation of pancreatic growth by CCK in mice.

The purpose of this study was to test the hypothesis that circulating ethanol at concentrations of approximately 0.1 mg% stimulates pancreatic secretion. Awake rats recovered from surgery were used in these experiments. Intravenous infusion protocols were established that produced blood ethanol concentrations 0.1 mg% for over an hour. Maintenance of 0.1 mg% blood ethanol concentration or transient concentrations as high as 0.17 mg% did not cause significant increases in pancreatic protein or fluid secretion. To test whether elevated blood ethanol would augment stimulated pancreatic secretion, the trypsin inhibitor camostat was infused intraduodenally at doses of 0.05, 0.2, and 0.5 mg/hr, each dose level infused for 2 hours. Elevated blood ethanol concentrations (0.1 mg%) did not significantly affect camostat-stimulated pancreatic protein or fluid secretion. In contrast to intravenous infusion, intraduodenal infusion of ethanol significantly stimulated pancreatic protein and fluid secretion, which was associated with blood ethanol concentrations of > or =0.19 mg%. The increases in pancreatic secretion were completely blocked by intravenous infusion of the cholecystokinin (CCK) receptor antagonist CR1409. We conclude that circulating ethanol does not stimulate pancreatic secretion in awake, recovered rats and that intraduodenal ethanol-stimulated pancreatic secretion is mediated by CCK.

Recent studies demonstrated that cholecystokinin (CCK) at physiological levels stimulates pancreatic enzyme secretion via a capsaicin-sensitive afferent vagal pathway. This study examined whether chemical ablation of afferent vagal fibers influences pancreatic growth and secretion in rats. Bilateral subdiaphragmatic vagal trunks were exposed, and capsaicin solution was applied. Pancreatic wet weight and pancreatic secretion and growth in response to endogenous and exogenous CCK were examined 7 days after capsaicin treatment. Perivagal application of capsaicin increased plasma CCK levels and significantly increased pancreatic wet weight compared with those in the control rats. Oral administration of CCK-1 receptor antagonist loxiglumide prevented the increase in pancreatic wet weight after capsaicin treatment. In addition, continuous intraduodenal infusion of trypsin prevented the increase in plasma CCK levels and pancreatic wet weight after capsaicin treatment. There were no significant differences in the expression levels of CCK-1 receptor mRNA and protein in the pancreas in capsaicin-treated and control rats. Intraduodenal administration of camostat or intravenous infusion of CCK-8 stimulated pancreatic secretion in control rats but not in capsaicin-treated rats. In contrast, repeated oral administrations of camostat or intraperitoneal injections of CCK-8 significantly increased pancreatic wet weight in both capsaicin-treated and control rats. Present results suggest that perivagal application of capsaicin stimulates pancreatic growth via an increase in endogenous CCK and that exogenous and endogenous CCK stimulate pancreatic growth not via vagal afferent fibers but directly in rats.

Cholecystokinin (CCK) is an important physiologic mediator that regulates satiety and gastric emptying. We demonstrated previously that soybean peptone acts directly on rat small intestinal mucosal cells to stimulate CCK release. In the present study, we examined the effects of beta-conglycinin, a major component of soy protein, and its peptone on food intake and gastric emptying after an intraduodenal infusion of beta-conglycinin peptone in relation to CCK release and interaction with the mucosal cell membrane. Intraduodenal infusion of beta-conglycinin peptone inhibited food intake in a dose-dependent manner, but that of whole soy peptone or camostat did not. The suppression of food intake by beta-conglycinin peptone was abolished by an intravenous injection of devazepide, a selective peripheral CCK receptor antagonist. The beta-conglycinin peptone infusion strongly suppressed gastric emptying with marked increases in portal CCK levels. We also observed that the beta-conglycinin peptone dose dependently and more potently stimulated CCK release from isolated dispersed mucosal cells of the rat jejunum than did beta-conglycinin itself. This stimulation corresponded to the binding activity of the peptide or protein to solubilized components of the rat jejunum membrane as evaluated by surface plasmon biosensor. These results indicate that beta-conglycinin peptone suppresses food intake, and this effect may be due to beta-conglycinin peptone in the lumen stimulating endogenous CCK release with direct acceptance to the intestinal cells.

Assessment of the extent of bioavailability (EBA) of salmon calcitonin (sCT) from hypocalcemic effects after intranasal administration was presented in rats. An integrated pharmacokinetic-pharmacodynamic (PK-PD) model with the endogenous Ca regulation system was applied. The influence of camostat mesilate, a protease inhibitor, on absorption of sCT was also estimated. Camostat, coadministered intravascularly, delayed the elimination of sCT. Although the hypocalcemic effect of sCT after i.v. administration was accelerated when camostat was coadministered intravenously, the enhanced effect could not be expressed only by pharmacokinetic change of sCT, and then the pharmacological data in the presence of camostat were analyzed to obtain optimal PD parameters. For the absorption of sCT after i.n. administration, a saturable absorptive process and a zero-order kinetic clearance from the nasal cavity were introduced to the model. The regression curves fitted the observed data, and camostat caused both an increase in maximum absorption rate and a decrease in the clearance parameter compared with the control. According to this modified PK-PD relationship, plasma sCT concentrations following i.n. administration of sCT with camostat were predicted well using its pharmacological effects. The EBA of sCT calculated from the simulated concentrations increased more than 4-folds compared with the control study. These results indicate the potential for prediction of plasma sCT concentration from the hypocalcemic effect.

The synthetic trypsin inhibitor camostat has been used for the treatment of acute and chronic pancreatitis in Japan based on the evidences obtained from a rat experimental model. However, rats differ from other rodents and from humans in terms of lacking a gallbladder and no response of pancreatic bicarbonate secretion to cholecystokinin (CCK). In the present study, we determined whether oral administration of camostat showed a trophic effect in mice as observed in rats and whether the trophic effect, if substantial, was mediated via the CCK-A receptor, using CCK-A receptor gene targeting mice. The chow containing 0.1% camostat was fed to 8-month-old mice. Three- and seven-day treatments with camostat did not affect pancreatic wet weight in CCK-A receptor (+/-) mice. After 14-day treatment, the ratio of pancreatic wet weight/body weight was significantly lower in CCK-A receptor (-/-) than (+/+) mice. The protein and chymotrypsin contents were lower and amylase content was higher in CCK-A receptor (-/-) mice, compared to (+/+) mice. No pathological findings were observed by histological examination. Camostat has a trophic effect on the pancreas in mice and this effect is mediated via the CCK-A receptor, but is less potent than in rats.

An oral protease inhibitor, camostat mesilate (CM) has been used clinically for chronic pancreatitis (CP) in Japan, but it lacks enough scientific evidence of its effectiveness. The aim of this study was to analyze the effect of CM on the gene expressions of pancreatitis-associated protein (PAP), p8, and cytokines such as interleukin-6 and transforming growth factor-beta1 in spontaneous CP model (WBN/Kob rats). CM (10 mg/100 g body weight), mixed in MB-3 diet, was administered orally and gene expressions were analyzed by reverse transcription-polymerase chain reaction. In untreated WBN/Kob rats, the gene expressions of all the four factors peaked at 12 weeks, whereas they were significantly suppressed in the CM-treated rats. CM significantly increased the body weight and pancreatic wet weight, and it significantly inhibited inflammatory changes and fibrosis of the pancreas. These results suggest that CM inhibits pancreatic inflammation and fibrosis through the suppression of gene expressions of PAP, p8, and cytokines in CP.

To characterise alkaline reflux oesophagitis after total gastrectomy in rats from the standpoints of cell proliferation and apoptosis and from its macroscopic and microscopic findings, and to evaluate the preventive and curative effects of camostat mesilate, a trypsin inhibitor.Open laboratory study.University hospital, Japan.70 male Wistar rats.Total gastrectomy with Billroth II anastomosis (n = 30) and with Roux-en-Y anastomosis (n = 30) were used to establish reflux oesophagitis. Camostat mesilate was given for prevention and cure. The remaining 10 animals had a sham operation.Trypsin activity of the oesophagus, macroscopic and microscopic findings, bromodeoxyuridine (BrdU) and apoptotic cell labelling indices.Reflux oesophagitis was more common and extensive after Billroth II than Roux-en Y anastomosis. The BrdU labelling index was increased in oesophagitis, while the apoptotic index did not change. Camostat mesilate was effective in both preventing and treating oesophagitis.Trypsin has an important role in the development of reflux oesophagitis after total gastrectomy.

Feedback regulation of pancreatic enzyme secretion is well established in animals, and their pancreases are able to adapt to intraduodenal inhibition of pancreatic enzymes by proteinase inhibitors such as Camostate (FOY-305; Schwarz GmbH, Monheim, Germany). In this study, we addressed whether similar adaptive changes occur in the human pancreas after 4 weeks of 2 g/day Camostate application.Before, at the end of, and 2 weeks after 4-week Camostate treatment (four times 500 mg daily), pancreatic changes were analyzed with the use of a secretin-cerulein test, a test-meal stimulation, cholecystokinin plasma measurement, and standardized ultrasonographic investigations of the pancreas.Duodenal trypsin output after secretion stimulation was significantly increased (+44%; P0.01) and duodenal bicarbonate output decreased 22% (P0.05) after 4 weeks of Camostate application. The size of the pancreatic head (vertical) increased 8% (P0.05) at week 4 and decreased to pretreatment values 2 weeks after treatment (week 6). The other three diameters measured (head oblique, body, and tail) showed a similar pattern. Stimulated cholecystokinin plasma levels 15 minutes after application of a standard test meal increased 62% (P0.05).The human pancreas adapts to oral application of the proteinase inhibitor Camostate. These findings support the theory that feedback control of the exocrine pancreas operates in humans.

The effect of methylcarbonylmethyl 2(S)-14-(4-guanidino-benzoyloxy) phenyl] propionate methanesulfonate (TT-S24) on experimental pancreatitis in rats was examined in comparison with that of camostat. TT-S24 showed a preventive effect on increases in plasma amylase activity and pancreatic weight induced by cerulein injection. TT-S24 also reduced an increase in plasma amylase activity induced by taurocholate. TT-S24 effectively prevented the mortality induced by an injection of a mixture of trypsin and taurocholate. TT-S24 showed no effect on an increase in amylase activity 6 h after duodenum ligation (closed duodenal loop pancreatitis), indicating that the drug had no effect on the initiation and propagation step of closed duodenal loop pancreatitis. On the other hand, TT-S24 reduced an increase in amylase activity 6 h after release of the duodenum ligation. TT-S24 showed anti-trypsin, anti-kallikrein, anti-thrombin and anti-plasmin activities. The effect of TT-S24 on some experimental pancreatitis models was nearly equal to or somewhat more potent in most instances to that of camostat. Therefore, TT-S24 should be useful in the clinical treatment of pancreatitis.

Patients with early non-insulin-dependent diabetes mellitus (NIDDM) empty glucose solutions from their stomachs more rapidly than non-diabetic control subjects, and this exacerbates postprandial hyperglycaemia. To determine if accelerated gastric emptying occurred in a rat model of NIDDM and influenced postprandial hyperglycaemia, gastric emptying of glucose was measured, and the effect of slowing the gastric emptying rate on postprandial hyperglycaemia was observed. We tested eight male obese Zucker diabetic rats and eight age-matched lean Zucker controls at 10-13 weeks of age to measure gastric emptying of glucose (by gamma scintigraphy). Rats fasted overnight were gavaged with 30% glucose at 1 ml/100 g body weight. Separately, six Zucker diabetic rats and six lean controls were tested for sensitivity to the inhibitory effects of cholecystokinin and secretin on gastric emptying. The diabetic rats emptied glucose significantly faster than controls (t1/2 = 37.3 +/- 1.5 vs 58.8 +/- 2.3 min in controls), and aging exaggerated this differential. Camostat, a stimulant of cholecystokinin and secretin release, added to the glucose meal significantly slowed gastric emptying (t1/2 = 123 +/- 23 and 166 +/- 19 min, diabetic vs lean, respectively), and significantly reduced postprandial hyperglycaemia in diabetic rats. Compared to Zucker lean controls, Zucker diabetic rats were as sensitive (cholecystokinin) or more sensitive (secretin) to gastrointestinal hormones that inhibit gastric emptying. The results demonstrate accelerated gastric emptying in a rat model of NIDDM, consistant with similar observations in humans with early NIDDM. These results also support the proposal that interventions to slow gastric emptying improve glucose control in this disease.

The effect of oral administration of protease inhibitor (camostat) on pancreatic morphology and exocrine function (conscious rat model) was investigated using WBN/Kob rats with spontaneous chronic pancreatitis. In nontreated WBN/Kob rats (2-12 months of age), pancreatic fibrosis and parenchymal destruction compatible with human chronic pancreatitis appeared at 3 months and advanced with each month. Pancreatic secretion was markedly impaired at all ages. In WBN/Kob rats fed diets containing camostat (from 2-3 or 4-5 months of age), the pancreas was hypertrophic and did not show any histological appearances compatible with chronic pancreatitis, and moreover, exocrine function was thoroughly restored with increased plasma cholecystokinin concentrations. Oral administration of protease inhibitor has both preventive and therapeutic effects on pancreatic lesions and dysfunction in an animal model of chronic pancreatitis, probably via endogenous cholecystokinin release.

Leukocytes are thought to have a role in tissue injury induced by stress. Synthetic protease inhibitors can suppress the leukocyte-dependent tissue injury; however, the effect of camostat mesilate on microcirculatory disturbance has not been reported. Male Wistar rats were anesthetized, and a 30% full skin-thickness dorsal scald burn was inflicted. Rolling or sticking of leukocytes and deposits of Monastral blue B (MBB) in gastric venules was observed by using intravital microscopy. Oral administration of camostat mesilate 100 mg/kg was performed twice: 40 minutes before the thermal injury and 2.5 hours after injury. Microscopy was performed 5 hours after the thermal injury, and showed that camostat mesilate suppressed the percentage of MBB deposit areas, and the rolling or sticking of leukocytes in the gastric venules. Camostat mesilate appears to protect against gastric microcirculatory disturbance induced by thermal injury in rats.

The fourth component of complement (C4) in urine was measured in 19 patients with systemic lupus erythematosus (SLE). Urinary C4 was detectable in all SLE patients using an enzyme linked immunosorbent assay. In 11 of 13 patients whose urinary C4 was serially measured, a decrease of urinary C4 was found in parallel with a decrease of disease activity of SLE. In the remaining 2 patients, the amount of C4 increased preceding a flare-up of the disease. The measurement of urinary C4 may be useful in evaluating the disease activity of SLE in individual patients and sometimes in predicting the flare-up of the disease. The specific hemolytic activity of excreted C4 and Western blotting analysis showed that urinary C4 consisted mainly of degraded fragments of C4. In two cases, camostat, a serine protease inhibitor, rapidly decreased the urinary C4 excretion, suggesting that the complement activation occurred in the glomerulus in lupus nephritis.

The effects of concomitant administration of a synthetic trypsin inhibitor (camostat) on pancreatic carcinogenesis in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP) were investigated. Thirty-two female Syrian golden hamsters were given weekly 10 mg/kg s.c. injections of BOP for 5 weeks while simultaneously receiving a 500 ppm camostat diet (BOP + camostat group). Additional groups of 30 animals received either the s.c. injections of BOP (BOP group), or the 500 ppm camostat diet (camostat group) during the same 5-week period. Thirty weeks after the first BOP administration, the incidence of pancreatic adenocarcinomas in the BOP + camostat group was significantly lower than in the group administered BOP only (p < 0.05). Similarly, the total numbers of pancreatic adenocarcinomas or dysplastic lesions were significantly decreased in the BOP + camostat group as compared with the BOP group (p < 0.01). None of the animals receiving camostat alone developed any adenocarcinomas or dysplastic lesions of the pancreas. The results of the present experiments clearly show that camostat can inhibit induction of hamster pancreatic ductal neoplasms when administered simultaneously with BOP.

Adaptive exocrine pancreatic growth is mediated primarily by dietary protein and the gastrointestinal hormone cholecystokinin (CCK). Feeding trypsin inhibitors such as camostat (FOY-305) is known to induce CCK release and stimulate pancreatic growth. However, camostat has also been reported to stimulate secretin release and, because secretin often potentiates the action of CCK, it could participate in the growth response. Our aim was to test the role of secretin in pancreatic development and adaptive growth through the use of C57BL/6 mice with genetic deletion of secretin or secretin receptor. The lack of secretin in the intestine or the secretin receptor in the pancreas was confirmed by RT-PCR. Other related components, such as vasoactive intestinal polypeptide (VIP) receptors (VPAC1and VPAC2), were not affected. Secretin increased cAMP levels in acini from wild-type (WT) mice but had no effect on acini from secretin receptor-deleted mice, whereas VIP and forskolin still induced a normal response. Secretin in vivo failed to induce fluid secretion in receptor-deficient mice. The pancreas of secretin or secretin receptor-deficient mice was of normal size and histology, indicating that secretin is not necessary for normal pancreatic differentiation or maintenance. When WT mice were fed 0.1% camostat in powdered chow, the pancreas doubled in size in 1 wk, accompanied by parallel increases in protein and DNA. Camostat-fed littermate secretin and secretin receptor-deficient mice had similar pancreatic mass to WT mice. These results indicate that secretin is not required for normal pancreatic development or adaptive growth mediated by CCK.

Chronic feeding of normal rats with camostate, a synthetic trypsin inhibitor, stimulates the growth of the pancreas chiefly by increasing cholecystokinin release. We examined the effects of camostate on the growth and the endocrine function of the pancreas in streptozotocin-induced diabetic rats. The pancreatic weight of the diabetic rats given camostate (200 mg/kg/day) by oral gavage for 14 days was significantly elevated by 120% over that of diabetic rats not given camostate, and was comparable to that in the nondiabetic rats given camostate. The total pancreatic contents of DNA, RNA, and protein in diabetic rats given camostate were also significantly higher than those in diabetic rats not given camostate, and did not differ from those observed in nondiabetic rats given camostate. The pancreatic growth seen in diabetic rats treated with camostate was associated with moderate hyperplasia and pronounced hypertrophy. By contrast, treatment with camostate did not improve hyperglycemia, hypoinsulinemia, or low pancreatic content of insulin seen in diabetic rats. These findings demonstrate a marked growth of the pancreas in diabetic rats stimulated by camostate, and suggest that camostate-induced pancreatic growth is not affected by the reduced level of the endogenous insulin. The present study also indicates that camostate has no beneficial effects on the function of residual B cells, failing to improve diabetes.

This study was undertaken to determine the effect of the single and combined administration of caerulein, hydrocortisone, and FOY-305 (camostat) on the regeneration of the remnant pancreas after a 90% pancreatectomy in rats. After undergoing either a sham operation or a 90% pancreatectomy, the rats were administered the three drugs either singly or in combination. After the rats were killed, the pancreas was weighed and examined for tissue amylase activity, tissue protein content and total DNA content. The results were as follows: In the sham operation group, the caerulein among three drugs produced a significant trophic effect. The trophic effect in the combined administration group was greater than that in the single administration group. In the 90% pancreatectomy group, of the three drugs administered, hydrocortisone produced the most significant trophic effect. The trophic effect in the combined administration group was greater than that in the single administration group. These data suggest that the trophic effect of caerulein is significant in mature pancreatic cells while that of hydrocortisone is an immature one and that an additive effect of the three drugs was observed.

The present study investigates the effect of oral pretreatment with the protease inhibitor camostate on the outcome of pancreatitis in three experimental models. In pancreatitis induced by overstimulation with cholecystokinin (CCK) in rats, pancreatic enzymes and the histological degree of pancreatitis were quantified; in pancreatitis induced by a choline-deficient ethionine-supplemented (CDE) diet in mice, the effect on survival was monitored; and in bile-induced pancreatitis in rats, the effect on survival, pancreatic enzymes, and histology was studied. Feeding of camostate (200 mg/kg/day) for 2 weeks worsened the histological degree of pancreatitis induced by overstimulation with CCK or by injection of taurocholate. The concentration of amylase in the pancreas and in serum was significantly lower after pretreatment with camostate, both in cerulein-induced pancreatitis and in bile-induced pancreatitis, while the concentration of trypsin in the pancreas was significantly increased in the camostate-treated animals. Pretreatment with camostate significantly lowered survival. In pancreatitis induced by a CDE diet, 3 of 20 mice survived the observation period, while 9 of 20 control animals survived (p < 0.05). In taurocholate-induced pancreatitis, 5 of 29 rats were alive after 3 days versus 18 of 30 animals in the control group (p < 0.001). CCK levels were not elevated in camostate-treated rats, when pancreatitis was induced 24 h after finishing camostate feeding. It is concluded that camostate induced pancreatic hypertrophy and increased concentration of proteolytic enzymes aggravate experimental panceatitis and that this is not mediated by increased CCK levels.

Prostasin, a glycosylphosphatidylinositol-anchored serine protease, regulates epithelial sodium channel (ENaC) activity. Sodium reabsorption through ENaC in distal nephron segments is a rate-limiting step in transepithelial sodium transport. Recently, proteolytic cleavage of ENaC subunits by prostasin has been shown to activate ENaC. Therefore, we hypothesized that serine protease inhibitors could inhibit ENaC activity in the kidney, leading to a decrease in blood pressure. We investigated the effects of camostat mesilate, a synthetic serine protease inhibitor, and FOY-251, an active metabolite of camostat mesilate, on sodium transport in the mouse cortical collecting duct cell line (M-1 cells) and on blood pressure in Dahl salt-sensitive rats. Treatment with camostat mesilate or FOY-251 decreased equivalent current (Ieq) in M-1 cells in a dose-dependent manner and inhibited the protease activity of prostasin in vitro. Silencing of the prostasin gene also reduced equivalent current in M-1 cells. The expression level of prostasin protein was not changed by application of camostat mesilate or FOY-251 to M-1 cells. Oral administration of camostat mesilate to Dahl salt-sensitive rats fed a high-salt diet resulted in a significant decrease in blood pressure with elevation of the urinary Na/K ratio, decrease in serum creatinine, reduction in urinary protein excretion, and improvement of renal injury markers such as collagen 1, collagen 3, transforming growth factor-beta1, and nephrin. These findings suggest that camostat mesilate can decrease ENaC activity in M-1 cells probably through the inhibition of prostasin activity, and that camostat mesilate can have beneficial effects on both hypertension and kidney injury in Dahl salt-sensitive rats. Camostat mesilate might represent a new class of antihypertensive drugs with renoprotective effects in patients with salt-sensitive hypertension.

1. 1. The role of endogenous CCK in the development of digestive enyme activities in small intestine and pancreas was investigated in suckling rats. Synthetic protease inhibitor (camostat 100 μg/g bwt) was orally administered twice daily for 5 days from 11 days of age. 2. 2. Pancreatic hypertrophy and hyperplasia, and alteration of pancreatic enzyme composition, especially decreases in amylase activity and increases in trypsin and chymotrypsin activities were produced by camostat treatment. These changes were completely suppressed by simultaneous administration of the potent CCK receptor antagonist L-364,718 (1 μg/g bwt). 3. 3. With camostat treatment, intestinal lactase activity decreased to 41%, while maltase and sucrase activities increased 3 and 2.5 times respectively. These changes in enzyme activities were not affected by the application of L-364,718. 4. 4. The mucosal disaccharidase and pancreatic enzyme activities could not be modified by chronic subcutaneous injection of camostat. The precocious induction of maltase and sucrase activities by camostat treatment was also observed in the adrenalectomized pups. 5. 5. These results indicate that pancreatic growth accompanied by alteration of digestive enzyme composition in the suckling rats is regulated by endogenous CCK, but the precocious induction of disaccharidase activities is not mediated by endogenous CCK released by camostat treatment.

In mice fed trypsin inhibitor (camostat) to elevate endogenous CCK, pancreatic growth plateaus by 7 days. It is unknown whether this represents the maximum growth capacity of the pancreas. To test the ability of CCK to drive further growth, mice were fed chow containing camostat (0.1%) for 1 wk, then fed standard chow for 1 wk, and finally returned to the camostat diet for a week. Pancreatic mass increased to 245% of initial value (iv) following 1 wk of camostat feeding, decreased to 147% iv following a 1 wk return to normal chow, and increased to 257% iv with subsequent camostat feeding. Camostat feeding was associated with significant increases in circulating CCK and changes in pancreatic mass were paralleled by changes in protein and DNA content. Moreover, regression of the pancreas following camostat feeding was associated with changes in the expression of the autophagosome marker LC3. Pancreatic protein synthetic rates were 130% of control after 2 days on camostat but were equivalent to control after 7 days. Changes in the phosphorylation of 4E-BP1 and S6, downstream effectors of mammalian target of rapamycin (mTOR), paralleled changes in protein synthetic rates. Cellular content of Akt, an upstream activating kinase of mTOR, decreased after 7 days of camostat feeding whereas expression of the E3 ubiquitin-ligases and the cell cycle inhibitor p21 increased after 2 days. These results indicate that CCK-stimulated growth of the pancreas is not limited by acinar cell mitogenic capacity but is due, at least in part, to inhibition of promitogenic Akt signaling.

To determine the effects of luminal protease inhibition on duodenal delivery and the intraluminal fate of pancreatic enzymes, six healthy subjects were intubated with an oro-ileal multilumen tube assembly. By using nonabsorbable markers, cumulative trypsin, chymotrypsin, lipase, and amylase activities were measured as delivered to duodenum, midjejunum, and distal ileum, with or without simultaneous duodenal perfusion of the protease inhibitor camostat at graded doses. Compared with saline, camostat (a) inhibited trypsin activity in the entire small intestinal lumen by up to 99%, and significantly reduced chymotrypsin activity by up to 89%; (b) significantly increased duodenal deliveries of lipase activity, amylase activity and volume; (c) did not influence plasma cholecystokinin concentrations; and (d) significantly increased jejunal and ileal deliveries of lipase but not amylase activity. Small intestinal transit and motility were not affected by camostat. In additional in vitro studies, camostat significantly reduced the spontaneous decline in lipase activity in fresh human duodenal juice incubated at 37°C. These findings demonstrate that duodenal deliveries of lipase and amylase activities increase when intraluminal protease activity is decreased; they suggest that this increase is not caused by slower proteolytic destruction of enzyme protein but by stimulation of pancreatic secretion. Thus, luminal protease-mediated feedback regulation of pancreatic secretion may be operative in humans. Because plasma cholecystokinin concentrations were not affected, these effects may in part be independent of cholecystokinin. The data further suggest that proteolytic digestion plays a major role in the rapid loss of luminal lipase activity on small intestinal transit.

This article suggests that for the concept of feedback regulation of the pancreas the application of animal data to humans has obvious limitations. The introduction of the synthetic protease inhibitor camostate (FOY 305) offered the possibility of designing studies in animals and man using the same compound as tool thus allowing reliable comparisons between the different experiments. These experiments revealed that cholecystokinin (CCK) has a dominant role in rats but it has no proven significance for feedback regulation in humans. The existence of such species differences should be kept in mind in studies dealing with pancreatic secretion, growth, pancreatitis, cancer, or related questions.

The therapeutic effect and the mechanism of action of the synthetic trypsin inhibitor camostate were studied in a rat model of acute interstitial pancreatitis induced by four subcutaneous injections of 20 micrograms/kg body weight of cerulein at hourly intervals. Rats with acute pancreatitis were given either 100 mg/kg body weight camostate or volume- and pH-adjusted water via an orogastric tube 30 min after the last cerulein injection. The elevation of serum amylase activity was significantly reduced by camostate treatment and the peak value was seen 1 hr earlier than that observed in the rats that did not receive camostate. Camostate also inhibited the reduction in pancreatic content of lipase and amylase seen during experimental pancreatitis. These effects were accompanied by alleviation of the histologic signs of acute pancreatitis such as cellular infiltration and acinar cell vacuolization. After oral administration, camostate and its metabolite were absorbed from the intestine and were detectable in plasma for more than 6 hr in concentrations high enough to have antiprotease activity. In addition, camostate in the duodenum was able to increase pancreatic juice flow and protein output and to stimulate endogenous secretin release. These results suggest that oral administration of camostate reduces the severity of cerulein-induced acute pancreatitis by releasing endogenous secretin and by its antiprotease activity.

We examined the pattern of expression of several proto-oncogenes during nonneoplastic growth and in acinar cell neoplasms in the rat pancreas. The levels of c-myc, c-raf-1, and c-Ki-ras mRNAs were increased in regenerating pancreata following surgical partial pancreatectomy and following administration of camostat. We also investigated proto-oncogene expression associated with the progression of pancreatic cancers in azaserine-treated rats. Injection of a single dose (30 mg/kg) of azaserine (O-diazoacetyl-L-serine) to 14-d-old rats leads to a variety of neoplastic lesions in the rat pancreas. Total RNA was isolated from lesions in various stages of tumor progression, including adenomas, carcinomas in situ, and invasive carcinomas. We observed increased expression of c-myc, c-raf-1, and c-Ki-ras in azaserine-induced adenomas and carcinomas. Actin expression was also increased in these tissues, whereas amylase expression was variable. However, when compared to the normal growing pancreas, the level of proto-oncogene expression in the adenomas and carcinomas was disproportionate to the degree of cellular division in those tissues. Thus, the alterations induced by azaserine apparently caused a deregulated increase in expression of cellular oncogenes associated with growth regulation.

It has been shown in the rat that endogenous cholecystokinin (CCK), released in response to the non-nutrient trypsin inhibitor camostat, reduces food intake at meals and increases Fos-like immunoreactivity (Fos-LI; a marker for neuronal activation) in the dorsal vagal complex (DVC) of the hindbrain but not the myenteric plexus of the duodenum and jejunum. Experiment 1: We examined Fos-LI in the myenteric and the submucosal plexuses of the gut in response to orogastric gavage of camostat in rats. As we reported previously, camostat failed to increase Fos-LI in the myenteric plexus. We show here that camostat increased Fos-LI in the submucosal plexus of the duodenum and jejunum. Camostat also increased Fos-LI in the DVC. Experiment 2: Pretreatment with devazepide, a specific CCK1 receptor antagonist abolished camostat-induced Fos-LI in the submucosal plexus and the DVC. Experiment 3: Bilateral subdiaphragmatic vagotomy reduced camostat-induced Fos-LI in the submucosal plexus approximately 40% and abolished it in the DVC. Conclusions: Activation of the submucosal plexus by cholecystokinin at the CCK1 receptor accompanies stimulation of the dorsal vagal complex of the hindbrain and inhibition of food intake. Unlike the submucosal plexus, activation of the myenteric plexus is not necessary for cholecystokinin's influence on the dorsal vagal complex and food intake. The lack of activation in the myenteric plexus after camostat stimulation, in contrast to nutrient releasers of CCK such as oleate, suggests that intestinal stimulants can either release different amounts of CCK or cause release of CCK from I cells with different molecular forms of CCK. This would suggest that CCK-8 is released by camostat and is not able to travel to the myenteric plexus while a more stable form of CCK such as CCK-58 can travel to this site that is further away from the I cell.

We hypothesized that endogenous CCK reduces food intake by activating the dorsal vagal complex (DVC) and the myenteric neurons of the gut. To test this hypothesis, adult rats were given camostat mesilate; a nonnutrient releaser of endogenous CCK, by orogastric gavage, and Fos-like immunoreactivity (Fos-LI) was quantified in the DVC and the myenteric plexus. The results for endogenous CCK were compared with those for exogenous CCK-8. Exogenous CCK-8 reduced food intake and stimulated Fos-LI in the DVC and in myenteric neurons of the duodenum and jejunum. In comparison, endogenous CCK reduced food intake and increased DVC Fos-LI but did not increase Fos-LI in the myenteric plexus. Similar to CCK-8, devazepide, a specific CCK1 receptor antagonist, and not L365,260, a specific CCK2 receptor antagonist, attenuated the reduction of food intake by camostat. In addition, Fos-LI in the DVC in response to both exogenous CCK-8 and camostat administration was significantly attenuated by vagotomy, as well as by blocking CCK1 receptors. These results demonstrate for the first time that reduction of food intake in adult rats by endogenous CCK released by a nonnutrient mechanism requires CCK1 receptors, the vagus nerve, and activation of the DVC, but not the myenteric plexus.

Background: Differentiation between functional dyspepsia and early chronic pancreatitis is difficult because these diseases do not produce specific abnormalities in laboratory testing. The aim of this study was to examine the potential efficacy of camostat mesilate, a protease inhibitor, against functional dyspepsia and to characterize patients with favorable responses. Methods: Dyspeptic patients who exhibited no abnormalities on laboratory blood and urine testing, abdominal ultrasonography and upper gastrointestinal endoscopy were randomized to receive camostat mesilate 200 mg three times daily or famotidine 20 mg twice daily for 4 weeks. Symptoms severity was recorded before and at 2 and 4 weeks after starting treatment using a visual analog scale. Results: Epigastralgia was significantly improved after 2 and 4 weeks of treatment in both groups (P

Background Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type 2 diabetes, lacks the expression of cholecystokinin-1 receptor mRNA and exhibits inflammation and degeneration of the pancreas and eventually develops insulinopenic diabetes. Protease inhibitors are known to modulate inflammatory response and fibrosis as well as inhibit proteases activity. Aim To examine the effects of long-term treatment with camostat, a synthetic protease inhibitor, on metabolic and histopathological changes in the islets of OLETF rats. Method OLETF rats were fed either camostat-containing food (200 mg/100 g) from 12 or 28 weeks of age to 72 weeks of age, or fed standard rat diet. Results Camostat-fed rats gained less weight or lost weight, although they consumed more food than the control rat when food intake was adjusted for body weight. Camostat reduced visceral adipose depots and fasting serum concentrations of triglyceride, free fatty acids, cholesterol, glucose, and insulin. Pancreatic insulin content in camostat-treated rats was significantly higher than in control rats. Immunohistochemistry revealed marked suppression of expressions of tumor necrosis factor α , interleukin 1 β , interleukin 6, and α -smooth muscle actin in the islets of camostat-treated rats, compared with control rats. Histologically, disruption of the islets and pancreatic fibrosis were noted in control rats but not in camostat-fed rats. Conclusion Our findings suggest that camostat prevents and reverses obesity, hyperinsulinemia, hyperglycemia, and hyperlipidemia and markedly inhibits inflammation, fibrosis, and disruption of the islets in the genetically obese diabetic OLETF rats.

A four-year-old male with steroid refractory nephrotic syndrome was found to have diffuse deposition of α2-macroglobulin (α2M) in the glomeruli which showed diffuse mesangial pro

Background & Aims: Cholecystokinin (CCK) is known to stimulate the synthesis of digestive enzymes in the pancreas at the translational level. We investigated in vivo the biochemical regulation of initiation factors important for the stimulation of translation of digestive enzyme protein in rat pancreas by CCK. Methods: Intraperitoneal injection of CCK or intragastric administration of a trypsin inhibitor to elicit endogenous CCK release was followed by removal and preparation of pancreas for protein evaluation. Isoelectric focusing was used to evaluate the phosphorylation of the initiation factor eIF4E, and Western blotting and immunoprecipitation followed by Western blotting were used to study the phosphorylation state and amount of other interacting factors. Results: CCK treatment induced a time- and dose-dependent phosphorylation of pancreatic eIF4E and its binding protein (PHAS-I). Because the release of eIF4E from its binding protein as a result of phosphorylation is followed by formation of a messenger RNA cap–binding complex that includes the initiation factor eIF4G, we evaluated the association of eIF4G with released eIF4E and showed that it was increased by CCK. These events occurred over a range of CCK doses from 0.2 to 5 μg/kg. We also evaluated the effect of endogenous CCK by administering a synthetic trypsin inhibitor, camostat (100 mg/kg). Camostat treatment markedly increased the phosphorylation of both PHAS-I and eIF4E and the formation of eIF4E-eIF4G complex. Thus, both exogenous and endogenous CCK activate translational initiation factors in vivo. Conclusions: Activation of translational machinery necessary for initiation of protein synthesis likely contributes to the normal postprandial synthesis of pancreatic digestive enzymes. GASTROENTEROLOGY 2000;119:1731-1739