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A 69-year-old woman without pre-existing disease visited our hospital due to general malaise, diarrhea, and arthralgia 3 days after a uterine cancer test. We diagnosed her with sepsis of unknown focus and started treatment immediately, but she died 20 hours after the first visit due to multi-organ failure and septic shock. Later, group A streptococcus was detected from the blood culture, and streptococcal toxic shock syndrome (STSS) was diagnosed. The strain had the emm28 genotype and a mutation in csrR with increased NADase activity. These virulence factors were considered to be related to STSS development in this patient.

Soft tissue sarcomas (STSs) are heterogeneous and aggressive malignancies with few effective therapies available. We have developed T cells expressing a vascular endothelial growth factor receptor 2 (VEGFR2)-specific chimeric antigen receptor (CAR) to establish a tumor angiogenesis-specific CAR-T cells impacting cancers (TACTICs) therapy. In this study, we optimized the manufacturing and transportation of mRNA-transfected anti-VEGFR2 CAR-T cells and collected information that allowed the extrapolation of the efficacy and safety potential of TACTICs therapy for STS patients. Although 5-methoxyuridines versus uridines did not improve CAR-mRNA stability in T cells, the utilization of CleanCap as a 5' cap-structure extended the CAR expression level, increasing VEGFR2-specific cytotoxicity. Furthermore, 4 °C preservation conditions did not affect the viability/cytotoxicity of CAR-T cells, contrarily to a freeze-thaw approach. Importantly, immunohistochemistry showed that most of the STS patients' specimens expressed VEGFR2, suggesting a great potential of our TACTICs approach. However, VEGFR2 expression was also detected in normal tissues, stressing the importance of the application of a strict monitoring schedule to detect (and respond to) the occurrence of adverse effects in clinics. Overall, our results support the development of a "first in humans" study to evaluate the potential of our TACTICs therapy as a new treatment option for STSs.

Pemafibrate, a selective peroxisome proliferator-activated receptor (PPAR) α modulator, is a new drug that specifically modulates PPARα conformation and co-activator recruitment, thereby lowers plasma triglycerides with less off-target effects. Classical PPARα ligands such as fenofibrate suppress inflammatory cells including microglia. However, effects of pemafibrate on microglia have never been addressed. Here we show that pemafibrate, like other PPARα ligands, potently suppressed NF-κB phosphorylation and cytokine expression in microglial cells. PPARα knockdown significantly amplified LPS-induced cytokine expression. Pemafibrate-induced suppression of IL-6 expression was reversed by PPARα knockdown. However, suppression by fenofibrate was not reversed by PPARα knockdown but by Sirtuin 1 (SIRT1) knockdown. In conclusion, pemafibrate and fenofibrate similarly suppresses microglial activation but through distinct PPARα and SIRT1-dependet pathways., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A 40-year-old Japanese woman presented to our hospital with general fatigue and muscle weakness. She had a history of premature loss of deciduous teeth at 4 years old, her serum alkaline phosphatase (ALP) activity was as low as 91 U/L, and radiologic studies revealed thoracic deformity and sacroiliac calcification. Genetic sequencing revealed a heterozygous c.1559delT mutation in the tissue non-specific alkaline phosphatase gene (ALPL). Based on these findings, she was diagnosed with hypophosphatasia (HPP), and treatment with asfotase alfa, a recombinant human tissue-nonspecific alkaline phosphatase (TNSALP), was initiated. After six months of treatment with asfotase alfa, improvements were observed in the SF-36 score, six-minute walk distance, and grasping power. Although the overdiagnosis needs to be avoided, HPP should be considered in patients with undiagnosed musculoskeletal symptoms and a low serum ALP activity.

We visualize plasmon mode patterns induced in a single gold nanorod by three-dimensional scanning near-field optical microscopy. From the near-field transmission imaging, we find that 3rd and 4th order plasmon modes are resonantly excited in the nanorod. We perform electromagnetic simulations based on the discrete dipole approximation method under focused Gaussian beam illumination and demonstrate that the observed near-field spectral and spatial features are well reproduced by the simulation. We also reveal from the three-dimensional near-field microscopy that the 4th order plasmon mode confines optical fields more tightly compared with the 3rd order mode. This result indicates that the even-order plasmon modes are promising for enhancing the light-matter interactions.

It is reported that statins have inconsistent effects on glycemic status and adiponectin concentrations in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the effect of statins on these variables in patients with T2DM and hypercholesterolemia. A control group comprising 24 patients with T2DM but without hypercholesterolemia was observed for more than 12 weeks, while 24 patients with T2DM and hypercholesterolemia were treated with statins for the same period (statin group). The percentage changes in the glycemic status [blood glucose and glycated hemoglobin (HbA1c)], and levels of plasma adiponectin [total and high molecular weight (HMW)] were compared between the two groups. The statin group had reduced percentage changes in HbA1c, blood glucose, and total and HMW-adiponectin concentration percentage changes that were similar to those in the control group. However, when matched for sex, age (±5 years) and HbA1c (±0.5%) with the control group, the pravastatin group had reduced percentage changes in the plasma HMW-adiponectin concentrations than the matched controls (p=0.023). However, there were no differences in the percentage changes in the plasma total adiponectin (p=0.137), HbA1c (p=0.202), or blood glucose concentrations (p=0.450) between the two groups. Pravastatin treatment had no effect on the glycemic status of patients with T2DM and hypercholesterolemia, but may reduce the percentage changes in the plasma HMW-adiponectin concentrations. Hence, patients with T2DM and hypercholesterolemia receiving long-term treatment with pravastatin might experience increased insulin resistance.

A detailed characterization of plasmon modes is important not only for a deeper understanding of plasmons but also for their practical applications. In this study, we investigated the three-dimensional near-field characteristics of high-order plasmon modes excited in a gold hexagonal nanoplate. From the near-field spectroscopic images, we found that both in-plane and out-of-plane plasmon modes observed near 900 nm were spectrally and spatially overlapped. We performed three-dimensional near-field measurement to reveal the optical characteristics of the overlapped modes in detail. We found that the steric near-field distribution near the nanoplate strongly depended on the plasmon mode, and the out-of-plane mode confines electromagnetic fields more tightly than the in-plane mode. We also found that the in-plane mode was dominantly visualized as the probe tip-sample distance increased. These findings demonstrate that the three-dimensional near-field technique enables selective visualization of a single plasmon mode even if multiple modes are spatially and spectrally overlapped.

We herein describe a case of pulmonary tumor thrombotic microangiopathy (PTTM) with rapidly progressing colon cancer. A 61-year-old man who had been receiving treatment for type 2 diabetes mellitus for 3 years was hospitalized due to critical hypoxemia. Computed tomography, which had not shown any abnormalities 3 months previously, revealed a tumor in the ascending colon, multiple nodules in the liver, and the absence of any lung abnormalities. On day 3 of hospitalization, a sudden onset of severe dyspnea and tachycardia occurred, followed by death. Autopsy revealed microscopic metastatic tumor emboli in multiple pulmonary vessels with fibrin thrombus and intimal proliferation, which led to a diagnosis of PTTM.

Precise understanding of the spatiotemporal characteristics of plasmons is essential for the development of applications of plasmonic nanoparticles. In this study, we investigated the spatiotemporal properties of high-order plasmon modes induced in a gold triangular nanoplate by static and dynamic near-field measurements. The near-field transmission measurements revealed that in-plane and out-of-plane polarized plasmon modes were simultaneously excited and these modes spectroscopically and spatially overlapped. The superposition of these modes was visualized in the near-field two-photon excitation image of the nanoplate. We performed time-resolved autocorrelation measurements on the nanoplate and found that the correlation width was broader than the excitation pulse due to the plasmon dephasing process. From the correlation width map of the nanoplate, we experimentally demonstrated that the out-of-plane plasmon mode exhibits a longer dephasing time than the in-plane plasmon mode. These findings indicate that the out-of-plane mode is desirable for improving the performance of plasmons in various applications.

Cancer is one of the major causes of death in diabetic patients, and an association between antidiabetic drugs and cancer risk has been reported. Such evidence implies a strong connection between diabetes and cancer. Recently, glucagon has been recognized as a pivotal factor implicated in the pathophysiology of diabetes. Glucagon acts through binding to its receptor, glucagon receptor (GCGR), and cross-talk between GCGR-mediated signals and signaling pathways that regulate cancer cell fate has been unveiled. In the current study, expression of GCGR in colon cancer cell lines and colon cancer tissue obtained from patients was demonstrated. Glucagon significantly promoted colon cancer cell growth, and GCGR knockdown with small interfering RNA attenuated the proliferation-promoting effect of glucagon on colon cancer cells. Molecular assays showed that glucagon acted as an activator of cancer cell growth through deactivation of AMPK and activation of MAPK in a GCGR-dependent manner. Moreover, a stable GCGR knockdown mouse colon cancer cell line, CMT93, grew significantly slower than control in a syngeneic mouse model of type 2 diabetes with glycemia and hyperglucagonemia. The present observations provide experimental evidence that hyperglucagonemia in type 2 diabetes promotes colon cancer progression via GCGR-mediated regulation of AMPK and MAPK pathways., Competing Interests: CONFLICTS OF INTEREST The authors declare that there is no duality of interest associated with this manuscript.

Background: Parathyroid hormone-related protein (PTHrP) that causes hypercalcemia of malignancy appears to function as an endogenous smooth muscle relaxant. For example, PTHrP released upon bladder wall distension relaxes detrusor smooth muscle to accommodate urine. Here, we explored mechanisms underlying PTHrP-induced suppression of the smooth muscle contractility in the gastric antrum that also undergoes a passive distension., Methods: Effects of PTHrP on phasic contractions and electrical slow waves in the antral smooth muscle of the guinea pig stomach were studied using isometric tension and intracellular microelectrode recordings, respectively. Fluorescent immunohistochemistry was also carried out to identify the distribution of PTH/PTHrP receptors., Key Results: Parathyroid hormone-related protein (1-100 nM) reduced the amplitude of phasic contractions and the basal tension. N ω -nitro-l-arginine (L-NA, 100 μM), a nitric oxide (NO) synthase inhibitor, or 1H-[1,2,4]oxadiazolo-[4, 3-a]quinoxalin-1-one (ODQ, 10 µM), a guanylate cyclase inhibitor, diminished the PTHrP (10 nM)-induced reduction in the amplitude of phasic contractions. SQ22536 (300 μM), an adenylate cyclase inhibitor, attenuated the PTHrP-induced reduction in basal tension. The combination of ODQ (10 μM) and SQ22536 (300 μM) inhibited the PTHrP-induced reductions in both phasic contractions and basal tension. PTHrP (100 nM) had no inhibitory effect on the electrical slow waves in the antral smooth muscle. PTH/PTHrP receptors were expressed in cell bodies of PGP9.5-positive neurons in the myenteric plexus., Conclusions & Inferences: Parathyroid hormone-related protein exerts its inhibitory actions on the antral smooth muscle via both nitric oxide-cyclic guanosine monophosphate (NO-cGMP) and cyclic adenosine monophosphate (AMP) pathways. Thus, PTHrP may act as an endogenous relaxant of the gastric antrum employing the two complementary signaling pathways to ensure the adaptive relaxation of stomach., (© 2017 John Wiley & Sons Ltd.)

Clinicians sometimes encounter difficulty in diagnosing hypoglycaemia. Here, we present a case report of a 53-year-old woman with recurrent nocturnal hypoglycaemia. A continuous glucose monitoring system (CGMS) revealed postprandial hyperglycaemia and subsequent hypoglycaemia, and an oral glucose tolerance test showed an impaired glycaemic and delayed hyperinsulinaemic pattern. On the basis of these clinical findings, we diagnosed her unexplained hypoglycaemia as reactive hypoglycaemia. CGMS showed a sharp contrast of diurnal variation in blood glucose levels including hypoglycaemia between before and after treatment with an alpha-glucosidase inhibitor, voglibose. Her hypoglycaemic attacks disappeared., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Competing Interests: Competing interests: None declared.

We developed an advanced near-field optical method by combining an ultrafast near-field optical microscope with a prism-based pulse shaping system. We used this apparatus to visualize plasmonic optical fields and to measure the lifetime of plasmons excited on a rough gold film. We also studied the influence of the phase-modulation of the excitation pulse on the spatial distribution of the optical fields. We found that the spatial distribution of the optical fields can be controlled by a negatively chirped pulse.

Aim: Patients with long-standing diabetes commonly develop diabetic encephalopathy, which is characterized by cognitive impairment and dementia. To identify potential treatments for diabetic encephalopathy, we focused on the protective action of glucagon-like peptide-1 (GLP-1) against neural cell apoptosis. In this study, we evaluated whether exposure of cells to GLP-1 leads to epidermal growth factor receptor (EGFR) transactivation and signaling through the PI3K/Akt/mTOR/GCLc/redox pathway, which we previously reported., Methods: We monitored the phosphorylation of EGFR and Akt in PC12 cells exposed to MG and GLP-1 that had been first incubated in the presence or absence of various inhibitors of EGFR transactivation., Results: DAPI staining revealed that pretreatment of cells with BiPS, HB-EGF and anti-TGF-α neutralization antibodies or AG1478 abrogated the ability of GLP-1 to rescue cells from MG-induced apoptosis. We show that exposure of PC12 cells to GLP-1 induces EGFR phosphorylation and that this effect was inhibited by prior exposure of the cells to BiPS, HB-EGF and anti-TGF-α neutralization antibodies or AG1478. Interestingly, these agents also diminished the capacity of GLP-1 to protect cells from MG-induced apoptosis. Moreover, these agents reduced GLP-1-induced phosphorylation of Akt. EGF itself also protected the cells from MG-induced apoptosis and induced phosphorylation of Akt, which was inhibited by LY294002., Conclusion: The neuroprotective effects of GLP-1 against MG-induced apoptosis are mediated by EGFR transactivation, which signals through the PI3K/Akt/mTOR/GCLc/redox pathway in PC12 cells., (Copyright © 2012 S. Karger AG, Basel.)

In this 12-week, randomized, double-blind, placebo-controlled trial, the efficacy and safety of transglucosidase (TGD) were compared with placebo in patients with type 2 diabetes mellitus (T2DM). At 12 weeks, TGD 300 mg/day and TGD 900 mg/day significantly reduced HbA1c (0.18 and 0.21%) and insulin concentration (19.4 and 25.0 pmol/l), respectively, vs. placebo. TGD 300 mg/day and TGD 900 mg/day also significantly reduced low-density lipoprotein cholesterol (0.22 and 0.17 mmol/l, respectively). TGD 900 mg/day significantly reduced triglyceride by 0.24 mmol/l and diastolic blood pressure by 8 mmHg. Placebo was associated with a significant increase from baseline in body mass index, alanine aminotransferase and aspartate aminotransferase (0.17 kg/m(2) , 3 and 2 U/l, respectively), whereas TGD was not. TGD 300 mg/day significantly increased high-molecular-weight adiponectin by 0.6 µg/ml. Adverse events did not differ significantly between the groups. TGD resulted in lowering of HbA1c and blood insulin level and improvements in metabolic and cardiovascular risk factors in T2DM., (© 2011 Blackwell Publishing Ltd.)

Exercise is a useful modality to ameliorate postprandial hyperglycemia. Here we show that a short bout (∼6 min) of stair climbing-descending exercise (STAIR) starting at 90 min after meal accelerates the decrease in blood glucose concentrations in middle-aged sedentary men with impaired glucose tolerance, although STAIR is easy to perform and keeps the exercise intensity at a moderate level.

Omeprazole, a proton pump inhibitor, is widely used for the treatment of patients with peptic ulcer, gastroesophageal reflux disease and functional dyspepsia (FD), although some studies have demonstrated that omeprazole delays gastric emptying. The purpose of this study was to investigate the efficacy of omeprazole on gastric motility including gastric myoelectrical activity and gastric emptying. This study was performed on 12 healthy volunteers. Gastric motility was evaluated with cutaneously recorded electrogastrography (EGG) and gastric emptying of semi-solid meals using the (13)C-acetic acid breath test. EGG and gastric emptying were measured before and after treatment with 20 mg omeprazole orally for 7 days. In the fasting state, the percentage of EGG normogastria increased significantly compared to the baseline. No significant changes were observed in other EGG parameters including the percentage of tachygastria and bradygastria in both fasting and postprandial states, and the power ratios between both before and after ingestion of omeprazole. In addition, administrated omeprazole did not show any significant differences in the gastric emptying parameters such as the half emptying time. We conclude that administration of omeprazole did not affect gastric motility but improved gastric myoelectrical activity. These effects of omeprazole may be one of the mechanisms involved in its efficacy in relieving dyspeptic symptoms in FD patients.

Circular smooth muscle preparations isolated from the rat proximal colon periodically generated two different amplitudes and frequencies of phasic contractions: large phasic contractions (LPC) with a frequency of about 1.5 times/min and small phasic contractions (SPC) with a frequency of about 9 times/min. Preparations with no attached longitudinal smooth muscle layer (and also myenteric layer) generated SPC alone, while those with no attached submucosal layer generated only LPC, indicating that the pacemakers of the LPC and SPC are distributed in the myenteric and submucosal layers, respectively. In intact preparations, transmural nerve stimulation (TNS) applied for 1-2 min with different frequencies (0.2-2 Hz) inhibited the phasic contractions. The amplitude of LPC was reduced at >0.25 Hz and abolished at >0.3 Hz, while the amplitude but not the frequency of SPC was reduced at >0.5 Hz (in a frequency-dependent way). The TNS-induced inhibitory responses were augmented by atropine and attenuated by N(omega)-nitro-L-arginine (L-NA). In the presence of L-NA and atropine, TNS elicited biphasic (inhibitory and following excitatory) responses. The former were not antagonized by apamin, guanethidine or suramin, while the latter were antagonized by capsaicin, suggesting an innervation by non-adrenergic non-cholinergic non-nitrergic (NANCNN) inhibitory and peptidergic excitatory nerves, respectively. In preparations with the longitudinal muscle layer removed, TNS inhibited only the amplitude of SPC, which was augmented by atropine and antagonized by L-NA. In intact preparations, muscarinic stimulation with acetylcholine increased the frequency of LPC, while nitrergic stimulation with sodium nitroprusside reduced the amplitude and frequency of LPC, and also the amplitude but not the frequency of SPC. These results indicate that the rat proximal colon has two types of pacemaker cells. Myenteric pacemaker cells which receive predominantly nitrergic, but also cholinergic, peptidergic and NANCNN innervation, and submucosal pacemaker cells that are not markedly influenced by intramural nerves.

Patients with long-standing diabetes commonly develop diabetic encephalopathy, which is characterized by cognitive impairment and dementia. Oxidative stress-induced neuronal cell apoptosis is a contributing factor. Glucagon-like peptide (GLP)-1 has recently become an attractive treatment modality for patients with diabetes. It also readily enters the brain, prevents neuronal cell apoptosis, and improves the cognitive impairment characteristic of Alzheimer's disease. Therefore, we investigated whether GLP-1 could protect against oxidative stress-induced neuronal cell apoptosis in pheochromocytoma (PC12) cells. PC12 cells were exposed to 1 mM methylglyoxal (MG) or MG plus 3.30 microg/ml GLP-1. Cell apoptosis, expression and phosphorylation of phosphatidylinositol-3 kinase/Akt/mammalian target of rapamycin/gamma-glutamylcysteine ligase catalytic subunit (GCLc), and redox balance were then determined. The data showed that MG induced PC12 apoptosis in accordance with the redox (glutathione (GSH) and GSH/glutathione disulfide [GSSG]) imbalance. GLP-1 protected against this MG-induced apoptosis, which corresponded to the phosphorylation of PI3K, Akt, and mTOR, as well as the upregulation of GCLc and the restoration of the redox imbalance. Inhibitors of PI3K (LY294002), Akt (Akt-I), and mTOR (rapamycin) reduced the GLP-1-induced GCLc upregulation and its protection against MG-induced PC12 apoptosis. The GLP-1-induced redox restoration was also attenuated by rapamycin. In conclusion, the neuroprotective effect of GLP-1 is due to an enhancement of PI3K/Akt/mTOR/GCLc/redox signaling.

It is well known that insulin resistance affects osteodystrophy, and there is an important relationship between insulin resistance and hepato-biliary disease. It is also well known that hepato-biliary and pancreatic disease is associated with osteodystrophy. In the present review, we describe the mechanism of diabetes and osteodystrophy due to hepato-biliary and pancreatic disease. Hepatic osteodystrophy is associated with malabsorption, abnormalities of vitamin D metabolism, inflammatory cytokines, receptor activator of NF-kappaB ligand, and insulin-like growth factor-1. In particular, tumor necrosis factor-alpha and malabsorption are important factors for viral and alcoholic hepatitis, respectively. Malabsorption due to steatorrhea is important for cholestatic disease and chronic pancreatitis. A greater focus on non-alcoholic steatohepatitis (NASH) and further investigations to clarify the relationship between osteodystrophy and NASH are needed.

Ascites caused by hypothyroidism is rare and the pathogenesis is unclear. Several reports have presented cases of progressive ascites with hypothyroidism and elevated tumor markers. We report a 31-year-old female case with massive ascites and elevated serum CA 125 concentrations. The patient had no typical feature of hypothyroidism except an accumulation of ascitic fluid which showed elevated total protein concentration and a high serum-ascites albumin gradient (SAAG). There was no finding of malignancy. Following thyroid hormone replacement, the ascites was completely resolved accompanied by reduced concentrations of serum CA125. In general, primary hypothyroidism with ascites presents with coexisting massive pericardial or pleural effusion. The massive ascites and increased serum CA125 concentrations may have led us to make the incorrect diagnosis of ovarian malignancy. The evaluation of thyroid function is useful to determine the pathology of high-protein ascites or elevated tumor markers, and ascites may be treatable by thyroid replacement therapy.

Diabetic gastropathy is suggested to be the result of not only an autonomic neuropathy but also to disorder of the spontaneous rhythmic motility of the gastric smooth muscle. Attempts were made to investigate the alteration of the effects of endothelin-1 (ET-1), which is known to enhance the spontaneous activity of gastrointestinal smooth muscle, on gastric activity in streptozotocin (STZ)-induced diabetic rats. STZ-induced diabetic rats were prepared by the injection of Sprague-Dawley (SD) rats with STZ (i.p.). Isometric mechanical responses were recorded in isolated circular smooth muscle strips of the stomach antrum, to measure changes in the rhythmicity of the smooth muscle. ET-1 (10 nM) significantly elevated the resting tension and the frequency of spontaneous contraction, but did not alter the amplitude of the spontaneous oscillatory contractions in normal rats. In diabetic rats, ET-1 elevated the resting tension, and spontaneous contractions were increased in frequency, however they were decreased in amplitude. In normal rats, sarafotoxin S6c (S6c, 10 nM), a selective ET(B) receptor agonist, elevated the resting tension slightly and increased both the frequency and amplitude of the spontaneous contractions. However, S6c significantly elevated the resting tension alone in STZ-induced diabetic rats. Selective stimulation of endothelin type A (ET(A)) receptors with ET-1, in the presence of a selective antagonist of ET(B) receptors, produced similar responses in the gastric muscle of both normal and diabetic rats. These results indicate that ET-1 elevates the resting tension and increases the frequency of the spontaneous oscillatory contractions in both normal and STZ-induced diabetic rats, to a similar extent. However, the specific actions on ET(B) receptors were quite different between the two: the elevating actions on the resting tension were much greater in STZ-diabetic rats than in normal rats. The results suggested the facilitation of ET(B) receptor signaling in the antrum during the pathogenesis of diabetic gastropathy.

Neutrophil-endothelial adhesion is a crucial step in vascular inflammation and is recognized as a direct cause of serious atherosclerosis-mediated diseases. We previously demonstrated that high concentrations of glucose increased adhesion in a protein kinase C (PKC)-dependent manner within 48 h of administration by increasing the surface expression of endothelial adhesion molecules. In this study, we focused on the effects of histamine 2 receptor antagonists on endothelial-neutrophil adhesion and on the surface expression of endothelial adhesion molecules mediated by high glucose levels. Histamine 2 receptor antagonists have pleiotropic effects; they not only block the secretion of gastric acid, but also inhibit cell-cell adhesion, resulting in inhibition of metastasis. However, relevant mechanisms of action are not yet fully understood. Of three histamine 2 receptor antagonists (cimetidine, ranitidine, and famotidine), only cimetidine significantly attenuated adhesion mediated by 48-h incubation with 27.8 mM glucose. Cimetidine was found to decrease the surface expression of endothelial adhesion molecules intercellular adhesion molecule-1 and P-selectin, but not E-selectin. To determine the effects of cimetidine on intracellular level, we examined the effects of cimetidine on PKC-induced changes in adhesion, as well as the effects of nitric oxide (NO) synthase inhibitors on cimetidine. We found that NO synthase inhibitors reduced the inhibitory effects of cimetidine, whereas cimetidine did not affect adhesion mediated by a PKC activator. These data suggest that cimetidine acts directly on endothelial cells to inhibit high-glucose-induced expression of adhesion molecules and neutrophil adhesion mediated by increasing endothelial NO production, but not by inhibiting PKC.

Background: Insulin induces endothelium-dependent vasodilatation, which may be casually related to the insulin resistance and hypertension. Endothelium-derived nitric oxide (NO) is the most important mechanism of insulin-induced vasodilatation, and a possible contribution of endothelium-derived hyperpolarizing factor (EDHF) is also considered. Attempts were made to observe the effects of insulin on acetylcholine (ACh)-induced hyperpolarization in the submucosal arteriole of the guinea pig ileum, the objective being to investigate possible involvement of EDHF in the actions of insulin., Methods: Conventional microelectrode techniques were applied to measure the membrane potential of smooth muscle cells in the submucosal arteriole. EDHF-induced hyperpolarization was elicited by ACh in the presence of both N(omega)-nitro-L-arginine (L-NNA) (100 microM) and diclofenac (1 microM)., Results: The resting membrane potential was -70.9 mV, and Ba(2+) (0.5 mM) depolarized the membrane to -33.0 mV. Insulin (10 microU/ml to 100 mU/ml) did not change the membrane potential in the absence or presence of Ba(2+). In the presence of Ba(2+), ACh (3 microM) hyperpolarized the membrane with two components, an initial large hyperpolarization followed by a slow and small one. Low concentration of insulin (100 microU/ml) did not alter the ACh-induced hyperpolarization. High concentration of insulin (100 mU/ml) shortened the time required to reach the peak amplitude and tended to increase the peak amplitude of the ACh-induced hyperpolarization., Conclusions: The data show that insulin enhances the ACh-induced hyperpolarization in the submucosal arterioles of the guinea pig ileum. The results suggested that EDHF also accounts for one of the endothelial factors involved in the insulin-induced vasodilatation.

Electrophysiological effects of endothelin-1 (ET-1) on circular smooth muscle of rat gastric antrum were investigated by using intracellular membrane potential recording techniques. ET-1 (10 nM) caused an initial hyperpolarization of the membrane which was followed by a sustained depolarization. ET-1 also increased the frequency but not the amplitude of slow waves. In the presence of the endothelin type A (ETA) receptor antagonist, BQ123 (1 microM), ET-1 (10 nM) depolarized the membrane and increased the frequency of slow waves, but without the initial hyperpolarization. The selective endothelin type B (ETB) receptor agonist, sarafotoxin S6c (10 nM), also depolarized the membrane and increased the frequency of slow waves. In the presence of the ETB receptor antagonist, BQ788 (1 microM), ET-1 (10 nM) hyperpolarized the membrane. However, in the presence of BQ788, ET-1 caused neither the depolarization nor the increase in the frequency of the slow waves. The ET-1-induced hyperpolarization was completely abolished by apamin (0.1 microM). In the presence of apamin, ET-1 depolarized the membrane and increased the frequency of slow waves. The ET-1-induced depolarization was significantly attenuated by 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS, 0.3 mM). The increase of the frequency by ET-1 was observed both in the presence and absence of DIDS. These results suggest that, ET-1 hyperpolarizes the membrane by the activation of Ca2+-activated K+ channels via ETA receptors, and depolarizes the membrane by the activation of Ca2+-activated Cl- channels via ETB receptors. ET-1 also appears to increase the frequency of slow waves via ETB receptors, however this mechanism would seem to be independent of membrane depolarization.

Objective: Endothelial-neutrophil adhesion is crucial for vascular injury, the major cause of diabetic vascular complications. On the other hand, platelet aggregation inhibitors, frequently used for diabetic patients with intermittent claudication, have been shown to decrease the incidence of atherosclerosis-mediated diseases (acute myocardial infarction and stroke). However, whether these agents act directly on the endothelial reactions to hyperglycemia remains unclear. Therefore, we examined their direct effects on endothelial-neutrophil adhesion and expression of endothelial adhesion molecules induced by high glucose., Methods and Results: After human endothelial cells were cultured in high glucose medium, neutrophils from healthy volunteers were added and allowed to adhere for 30 min. Adhered neutrophils were quantified by measuring their myeloperoxidase (MPO) activities, and surface expression of endothelial adhesion molecules was determined with an enzyme immunoassay. Of the platelet aggregation inhibitors tested, only cilostazol significantly attenuated the adhesion through decreasing expression of intercellular adhesion molecule-1 (ICAM-1) and P-selectin. In addition, nitric oxide (NO) synthase inhibitors reduced the inhibitory effects of cilostazol, but a protein kinase C (PKC) activator did not., Conclusions: Cilostazol may act directly on endothelial cells to inhibit expression of adhesion molecules and neutrophil adhesion induced by high glucose through increasing NO production.

Background and Aim: Many lines of evidence indicate that hyperinsulinemia might be associated with coronary atherosclerosis, and, currently, there are no effective strategies for preventing this. We previously reported that high insulin enhances neutrophil-transendothelial migration, a process that involves increased surface presentation of platelet endothelial cell adhesion molecule-1 (PECAM-1) through a mitogen-activated protein (MAP) kinase-dependent event. In this current study, we examined if antidiabetic agents, especially K(ATP) channel blockers, might similarly protect against the leukocyte-endothelial cell interactions enhanced by high insulin., Methods: Neutrophils transmigration across umbilical vein endothelial cells (in high insulin medium) with or without K(ATP) channel blockers was performed. Neutrophil migration was quantified by measuring myeloperoxidase, and surface expression of endothelial PECAM-1 was examined using cell-surface enzyme immunoassay., Results: Neutrophil-transendothelial migration and PECAM-1 expression were enhanced by insulin (100 micro U/mL, 24 h) and were attenuated by gliclazide (20 micro M), but not by other K(ATP) channel blockers (glibenclamide, nateglinide, and glimepiride). Neutrophil migration and PECAM-1 expression were also increased by the mitogen-activated protein (MAP) kinase activator, anisomycin (1 micro M), and also attenuated by gliclazide. Nitric oxide (NO) synthase inhibitors did not modify either gliclazide effect., Conclusions: Our results suggest that the K(ATP) channel blocker, gliclazide, blocks high insulin-mediated neutrophil migration and PECAM-1 expression. These gliclazide effects may be mediated through the inhibition of MAP kinase activation and are unrelated to NO production., (Copyright 2004 John Wiley & Sons, Ltd.)

Background and Aim: There are many lines of evidence indicating that hyperinsulinemia but not hyperglycemia is linked to the development of atherosclerotic diseases such as coronary events in diabetic patients. K(ATP) channel blockers of the sulphonylurea class are used widely to treat type 2 diabetes mellitus even with hyperinsulinemia. In this study, we determined whether K(ATP) channel blockers can protect against atherosclerotic processes enhanced by hyperinsulinemia, namely leukocyte-endothelial cell interactions. In addition, we characterized the intracellular mechanisms involved in protective actions of the K(ATP) channel blocker(s)., Method: Studies of adhesion between neutrophils and human umbilical vein endothelial cells incubated in insulin-rich medium with or without K(ATP) channel blockers were performed. Adhered neutrophils were quantified by measuring their myeloperoxidase activities, and surface expression of endothelial ICAM-1 was examined using an enzyme immunoassay., Results: Both neutrophil adhesion and ICAM-1 expression enhanced by high insulin (100 microU/ml, 48 h) were attenuated by gliclazide (20 microM), but not by other K(ATP) channel blockers (glibenclamide, nateglinide, and glimepiride). In addition, both neutrophil adhesion and ICAM-1 expression which were increased by a MAP kinase activator, anisomycin (1 microM), or a PKC activator, phorbol 12-myristate 13-acetate (10 nM) were also attenuated by gliclazide. Nitric oxide (NO) synthase inhibitors did not affect these effects of gliclazide., Conclusions: These results suggest that among K(ATP) channel blockers, only gliclazide can act directly on endothelial cells to inhibit neutrophil-endothelial cell adhesion and ICAM-1 expression enhanced by hyperinsulinemia. These effects of gliclazide are mediated through inhibiting activation of MAP kinase and PKC, unrelated to NO production.

Background and Aims: There is growing evidence that hyperinsulinemia is linked to the development of atherosclerosis in patients with diabetes. We demonstrated previously that high insulin exacerbates neutrophil-endothelial cell adhesion and endothelial intercellular adhesion molecule (ICAM)-1 expression through activation of protein kinase C (PKC) and mitogen-activated protein (MAP) kinase. Though 3-hydroxymethyl-3-glutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been employed as therapeutic agents in the treatment of dyslipidemia, which is frequently accompanied by diabetes mellitus; it is not known whether statins protect against leukocyte-endothelial interactions, especially in hyperinsulinemia. In this study, we determined which statin(s) could protect against endothelial reactions to high insulin., Methods: Studies of adhesion between neutrophils from healthy volunteers and human umbilical vein endothelial cells incubated in regular insulin-rich medium with or without statins were performed. Adhered neutrophils were quantified by measuring their myeloperoxidase (MPO) activities, and endothelial expression of ICAM-1 was examined using an enzyme immunoassay., Results: Both the increased neutrophil-endothelial cell adhesion and ICAM-1 expression caused by high insulin (100 microU/ml) for 48 h were significantly attenuated by pretreatment with cerivastatin (0.01 microM), but not by fluvastatin (0.5 microM) or pravastatin (0.05 microM). These protective actions of cerivastatin were attenuated by a key intermediate in the cholesterol biosynthesis pathway, mevalonate (400 microM). In addition, cerivastatin attenuated both neutrophil-endothelial cell adhesion and endothelial ICAM-1 expression enhanced by a MAP kinase activator, anisomycin (1 microM) but not by a PKC activator, PMA (10 nM)., Conclusions: These results suggest that through inhibiting MAP kinase but not PKC activation therapy with cerivastatin would be promising strategy for inhibiting neutrophil-endothelial cell adhesion and endothelial ICAM-1 expression enhanced by high insulin, which is closely correlated with atherosclerosis.

The electrophysiological properties of smooth muscle in the murine lower oesophageal sphincter (LOS) were investigated by intracellular microelectrode recording. Inhibitory junction potentials (IJPs) evoked by trains of field stimulation (30 V, 0.2-0.3 ms, 10 stimuli at 1-50 Hz) were observed in the murine LOS in the presence of atropine (1 microM) and nifedipine (1 microM). The IJP consists of two components, which we termed fast IJP and slow IJP. The fast IJP was partly sensitive to guanethidine (5 microM), pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS, 30 microM) and apamin (0.1 microM), suggesting that the fast IJP was produced partly through the activation of apamin-sensitive Ca2+-activated K+ channels and of P2-purinoceptors. The other part of the fast IJP was sensitive to N(omega)-nitro-L-arginine (L-NNA, 100 microM) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ, 1 microM), but insensitive to apamin (0.1 microM), iberiotoxin (50 nM) and charybdotoxin (30 nM). Slow IJP was sensitive to L-NNA (100 microM), ODQ (10 microM) and glibenclamide (10 microM), but insensitive to apamin (0.1 microM), iberiotoxin (50 nM) and charybdotoxin (30 nM). KT5823, a protein kinase G (PKG) inhibitor, had no effect on the fast and slow IJP in this tissue. It was suggested that, in the mouse LOS, adenosine trisphosphate (ATP) partly mediated the fast UP through apamin-sensitive Ca2+-activated K+ channels, and nitric oxide mediated the remained part of the fast IJP and the slow IJP through cGMP, but not PKG. ATP-sensitive K+ channels were suggested to be partly involved in the production of slow IJP, but the responsible channel(s) for the nitrergic fast IJP remained unclarified.

Neutrophil-endothelial adhesion is a crucial step in vascular inflammation, which is recognized as the direct cause of atherosclerosis-mediated serious diseases. We demonstrated previously that high glucose increased adhesion in a protein kinase C (PKC)-dependent manner within 48 h through increasing surface expression of endothelial adhesion molecules. On the other hand, statins, used for patients with hypercholesterolemia, have been shown to decrease the incidence of atherosclerosis-mediated diseases, but direct effects of statins on endothelial cells remain unclear. In this study, we examined the effects of these compounds on high glucose-mediated neutrophil-endothelial adhesion with respect to the participation of PKC and nitric oxide (NO). After human endothelial cells were cultured for 48 h in high glucose medium, neutrophils from healthy volunteers were added and allowed to adhere for 30 min. Adhered neutrophils were quantified by measuring their myeloperoxidase activities, and surface expression of endothelial adhesion molecules was determined with an enzyme immunoassay. Both pravastatin (0.05 microM) and fluvastatin (0.5 microM) significantly attenuated the adhesion mediated by 27.8 mM glucose for 48 h through decreasing surface expression of endothelial adhesion molecules (intercellular adhesion molecule-1, P-selectin, and E-selectin). NO synthase inhibitors reduced the inhibitory effects of statins, whereas statins did not affect the adhesion mediated by a PKC activator. These data suggest that statins act directly on endothelial cells to inhibit expression of adhesion molecules and neutrophil adhesion mediated by high glucose through increasing endothelial NO production, but not by inhibiting PKC.

Aim: Pioglitazone is considered to reduce insulin resistance. This study was conducted to evaluate the efficacy, safety and clinical profile of pioglitazone in patients whose type 2 diabetes were poorly controlled with alpha-glucosidase inhibitor alone or alpha-glucosidase in combination with sulfonylurea., Methods: Twenty patients with type 2 diabetes were treated with pioglitazone (30 mg q.d.) orally for 16 weeks., Results: There were significant reductions in HbA1C, FPG and postprandial plasma glucose at week 16. As adverse events, oedema, hypoglycaemia-like reaction, increases in LDH, CPK, etc. were noted. There was no significant change in TNF-alpha. Leptin levels increased significantly at week 16 and were still increasing 4 weeks after the treatment. Per cent body fat was almost constant throughout the study period. When efficacy was classified by demographic variables, pioglitazone was found to be more effective in the subjects who had a higher postprandial 2-h plasma glucose level, leptin level or per cent body fat value., Conclusion: Pioglitazone was considered to be effective when used in patients whose type 2 diabetes were poorly controlled with alpha-glucosidase inhibitor alone or alpha-glucosidase in combination with sulfonylurea.

Background: We previously reported that culture of endothelial cells in the presence of high glucose concentrations (27.8 and 55.5 mM) increase neutrophils adhesion because of the increase in endothelial adhesion molecules expression via activation of a protein kinase C (PKC) pathway. The antidiabetic sulfonylurea gliclazide, but not glibenclamide, inhibited these events, but the mechanisms involved were not clarified then. We present hereafter the results of further investigations of that effect with special reference to PKC activation., Methods: Human umbilical vein endothelial cells (HUVEC) were cultured for 48 h in a glucose-rich medium and neutrophils from healthy volunteers were then added and allowed to adhere for 30 min. Adhered neutrophils were quantified by measuring myeloperoxidase (MPO) activities and the surface expression of endothelial adhesion molecules was determined by enzyme immunoassay., Results: Culture in the presence of a high glucose concentration (27.8 mM for 48 h) increased neutrophils-endothelial cells adhesion and the surface expression of intercellular adhesion molecule-1 (ICAM-1), P-selectin, and E-selectin on the endothelial cells. These phenomena were significantly inhibited by gliclazide (20 microM). On the other hand, phorbol 12-myristate 13-acetate (PMA), a PKC activator, had an effect similar to a high glucose concentration and that effect was also inhibited by gliclazide., Conclusions: These data suggest that gliclazide inhibits high glucose-mediated neutrophils-endothelial cells adhesion and expression of endothelial adhesion molecules through inhibition of a PKC pathway.

Background: We have previously reported that endothelial cells cultured in the presence of high concentrations of glucose (27.8 and 55.5 mM) exhibited enhanced neutrophil adhesion through increased expression of endothelial adhesion molecules via the activation of a protein kinase C (PKC)-dependent pathway. We also found that the aldose reductase inhibitor, epalrestat, inhibited these events, but the mechanisms for this inhibition remained unclear. In this study, we further investigated the inhibitory mechanisms of epalrestat with reference to PKC activation and nitric oxide (NO) production., Methods: Human umbilical vein endothelial cells (HUVECs) were cultured for 48 h in glucose-rich medium and neutrophils from healthy volunteers were then added and allowed to adhere for 30 min. Adhered neutrophils were quantified by measuring myeloperoxidase (MPO) activity and surface expression of endothelial adhesion molecules was determined by enzyme immunoassay., Results: Culture in the presence of a high concentration of glucose (27.8 mM for 48 h) increased neutrophil-endothelial cell adhesion and surface expression of intercellular adhesion molecule-1 (ICAM-1), P-selectin, and E-selectin on endothelial cells. These phenomena were significantly inhibited by epalrestat (10 microM), while NO synthase (NOS) inhibitors reduced the inhibitory effects of this compound. In contrast, 10 nM phorbol 12-myristate 13-acetate (PMA), a PKC activator, showed similar effects as high glucose, and these effects were also inhibited by epalrestat., Conclusions: Our data suggested that epalrestat inhibited high glucose-mediated neutrophil-endothelial cell adhesion and expression of endothelial adhesion molecules not only through inhibition of a PKC-dependent pathway, but also through increased endothelial NO production.

1. The effects of endothelin-1 (ET-1) on guinea-pig lower oesophageal sphincter (LOS) circular smooth muscle were investigated by using intracellular microelectrodes and isometric tension recording techniques. 2. ET-1 produced biphasic mechanical responses; an initial transient relaxation followed by a sustained contraction. The initial relaxation was not inhibited by either tetrodotoxin (TTX, 1 microM) or L-N(G)-nitroarginine (L-NOARG, 100 microM). The sustained contraction was greatly attenuated by nifedipine (1 microM). 3. ET-1 (1 - 30 nM) induced a concentration-dependent hyperpolarisation that was unaffected by TTX or L-NOARG. The ET(A) receptor antagonist, BQ123 (0.3 microM) abolished the ET-1-induced hyperpolarisation, whereas the ET(B) receptor antagonist, BQ788 (0.3 microM) had no detectable effect. Sarafotoxin S6c (10 nM) did not change the membrane potential. 4. The ET-1-induced hyperpolarisation was abolished by apamin (0.1 microM). Interestingly, apamin abolished the ET-1-induced transient relaxation but potentiated the sustained contraction. 5. In Ca(2+)-free Krebs solution, the ET-1-induced hyperpolarisation was greatly attenuated and returned to the control value when the tissue was reperfused with Krebs solution containing Ca(2+). The ET-1-induced hyperpolarisation was insensitive to nifedipine but was attenuated by SK&F 96365 (1 - [beta-[3-(4 - methoxy - phenyl)propoxy] - 4 - methoxyphenethyl] - 1H-imidazole hydrochloride, 50 microM), an inhibitor of receptor-mediated Ca(2+) entry. The residual component of the ET-1-induced hyperpolarisation was sensitive to thapsigargin (1 microM). 6. These results demonstrate that, in guinea-pig LOS circular smooth muscle, ET-1 hyperpolarizes the membrane by activating apamin-sensitive K(+) channels, mainly as a result of receptor-mediated Ca(2+) entry and partly by Ca(2+) release from intracellular stores. The hyperpolarisation triggers the initial transient relaxation, which acts to oppose the sustained contraction.

Alteration of mechanical responses elicited by transmural nerve stimulation (TNS) was investigated in pylorus muscle of stomach isolated from mutant mice lacking expression of IP, type-1 receptor. In wild and mutant mice. TNS inhibited spontaneous contractions and generated an off-response at the cessation. The effects of inhibitors of neurotransmission revealed that in wild mice, acetylcholine and nitric oxide were involved as excitatory and inhibitory mediators, respectively. In mutant mice, a lack of nitroxidergic component with associated attenuation of cholinergic transmission was found. The off-response was inhibited by apamin in both mice. In mutant mice, spantide-sensitive excitatory response appeared in the presence of apamin. Acetylcholine and substance P enhanced while noradrenaline and sodium nitroprusside inhibited spontaneous contractions, in both wild and mutant mice; the actions were weaker in mutant mice than in wild mice for any agonists. The results indicate that pylorus smooth muscles receive cholinergic excitatory and nitroxidergic and non-adrenergic non-cholinergic inhibitory projections, and a lack of IP, type-1 receptor results in an impairment of cholinergic and nitroxidergic components, with no alteration of non-adrenergic non-cholinergic inhibitory projections. In addition, the mutation induces a substance P projection which is not detected in wild mice.

N,N'-Dicyanonaphthoquinodiimines fused with a pyrazine ring 1 were prepared from the corresponding quinones 4. The new acceptors 1 have a planar pi-system and undergo reversible two-stage 1e-reduction. Quaternization of the pyridyl substituent in 1d-f gave pyridinium derivatives 2d+, 2e+, and R-3+, respectively, which are stronger acceptors that undergo three-stage 1e-reduction. Upon electrochemical reduction of these cations, novel radicals 2d., 2e., and R-3. were generated and isolated as stable solids. The molecular geometries determined by X-ray analysis indicated that these radicals adopt a zwitterionic structure, in which the unpaired electron is located on the quinodiimine unit but not on the pyridyl group. These novel radicals undergo facile and reversible 1e-oxidation as well as two-stage 1e-reduction. The observed amphotericity endows the radicals with electrical conductivities (10(-5) to 10(-9) S cm-1), and these thus represent a new motif for single-component organic semiconductors.

1. The effects of inhibition of acetylcholine (ACh)-induced hyperpolarization on dilatation of submucosal arterioles were investigated in the guinea-pig ileum. 2. In smooth muscles of the arterioles depolarized by Ba(2+) (0.5 mM) to about -40 mV, ACh (3 microM) repolarized the membrane to about -65 mV (hyperpolarization), irrespective of the absence or presence of L-N(omega)-nitroarginine (L-NOARG, 0.1 mM) and diclofenac (1 microM), and increased the diameter (dilatation). 3. Combined application of charybdotoxin (CTX, 50 nM) and apamin (0.1 microM), inhibitors of some types of K(+)-channels, abolished the ACh-induced hyperpolarization and dilatation. 4. 18 beta-Glycerrhetinic acid (18 beta-GA, 30 microM), a known inhibitor of gap junctions, depolarized the membrane to about -36 mV, either in the absence or in the presence of Ba(2+), with no associated contraction of the arterioles. In the presence of 18 beta-GA, ACh-induced hyperpolarization was abolished, however the dilatation was inhibited only partially, with associated inhibition of constriction produced by Ba(2+) and NA. 5. 18 beta-GA inhibited the dilatation produced by sodium nitroprusside, an NO donor. 6. The ACh-induced hyperpolarization and dilatation were abolished in the presence of 2-aminoethoxydiphenyl borate (30 microM), an inhibitory modulator of inositol trisphosphate receptor-mediated Ca(2+) release from intracellular stores. 7. It is concluded that in submucosal arterioles, hyperpolarizations produced by ACh have causal relationship to the arteriolar dilatation. 18 beta-GA did not induce parallel relationship between hyperpolarization and dilatation produced by ACh. 18 beta-GA may have unidentified inhibitory effects on agonist-mediated actions, in addition to the inhibition of gap junctions.

1. Using the conventional whole-cell clamp method, the electrical responses of individual smooth muscle and endothelial cells to acetylcholine (ACh) were observed in multicellular preparations where the two types of cells remained in close apposition. 2. In both types of cells, ACh induced similar hyperpolarizing responses which, when recorded in current clamp mode, had two phases (an initial fast and a second slower phase). 3. After blocking gap junctions, including myoendothelial junctions, with 18beta-glycyrrhetinic acid, ACh induced an outward current with two phases in voltage-clamped endothelial cells. The outward current appeared around -90 mV and increased linearly with the membrane depolarization. 4. In smooth muscle cells, ACh failed to induce a membrane current after gap junctions had been blocked with 18beta-glycyrrhetinic acid. The inhibition of ACh-induced response by 18beta-glycyrrhetinic acid was observed using either sharp or patch electrodes. 5. Nominally Ca2+-free solution reduced the initial phase and abolished the second phase of ACh-induced responses of endothelial cells. Both phases were also reduced by charybdotoxin (CTX). 6. Our results indicate that in guinea-pig mesenteric arterioles, ACh hyperpolarizes endothelial cells by activating Ca2+-activated K+ channels which are sensitive to CTX. On the other hand, hyperpolarizing responses detected in smooth muscle cells seem to originate in endothelial cells and conduct to the muscle layer via myoendothelial gap junctions.

The effects of suramin on electrical and mechanical responses produced by adenosine triphosphate (ATP), acetylcholine and transmural nerve stimulation were observed in antrum smooth muscle isolated from the guinea-pig stomach. Suramin (>10(-6) M) inhibited the non-adrenergic non-cholinergic inhibitory junction potential, with no alteration of the resting membrane potential, slow wave and the ATP-induced responses (hyperpolarization and inhibition of slow waves). The amplitude, but not the frequency, of spontaneous rhythmic contraction was inhibited by suramin (>10(-5) M), with no alteration of electrical responses of the membrane. Transmural nerve stimulation elicited cholinergic excitatory and non-adrenergic non-cholinergic inhibitory responses on the spontaneous contraction, and suramin inhibited only the latter. Suramin did not alter the ATP-induced inhibition of spontaneous contraction. The contractions produced by low concentrations (<10(-7) M), but not high concentrations (10(-6) - 10(-5) M), of acetylcholine were inhibited by suramin. It is concluded that in smooth muscle of the guinea-pig antrum, suramin inhibits contractions produced spontaneously and by low concentrations of acetylcholine, with no relation to the electrical responses of the membrane. Parallel inhibition by suramin of the electrical and mechanical responses elicited by excitation of non-adrenergic non-cholinergic inhibitory nerves may not be causally related to the inhibition of ATP-receptors.

Inhibitory neurotransmission in guinea pig lower esophageal sphincter (LES) muscles was investigated by using electrophysiological methods. Transmural nerve stimulation (TNS) initiated an inhibitory junction potential (i.j.p.); the amplitude increased 35% by atropine (10(-6) M) and converted to a muscarinic excitatory junction potential (e.j.p.) by apamin (10(-7) M) plus Nomega-nitro-L-arginine (L-NNA, 10(-5) M). In atropinized tissue, the i.j.p. amplitude was reduced 58% by guanethidine (5 x 10(-6) M), 41% by L-NNA (10(-5) M), 57% by suramin (10(-4) M), and it was abolished by apamin (10(-7) M), suggesting that this potential was produced by ATP and nitric oxide (NO) released from adrenergic and nitrergic nerves, respectively, through the activation of Ca2+-sensitive K+ channels. Hyperpolarizations produced by ATP and NO were inhibited by apamin. The i.j.p. amplitude was reduced after desensitizing the membrane with ATP. In atropinized tissue, TNS produced a relaxation that was reduced 15% by guanethidine (5 x 10(-6) M), 50% by L-NNA (10(-5) M), and 30% by apamin (10(-7) M). Thus the LES receives cholinergic excitatory and adrenergic and nitrergic inhibitory innervations; the latter two components contribute evenly to the i.j.p. generation. The relaxation is mainly produced by NO in a membrane potential-independent way.

Only very rarely do multiple parapapillary choledochoduodenal fistulas occur concurrently with ampullary carcinoma. The following presents just such a case, which occurred in a 51 year-old Japanese female hospitalized for epigastralgia. Gastrointestinal fiberscopy (GIF) showed abnormal swelling of Vater's papilla. She was diagnosed as having ampullary carcinoma and choledochoduodenal fistulas, as determined by hypotonic duodenography (HDG), endoscopic retrograde cholangiopancreatography (ERCP) and from the histopathology of the ampullary mucosal biopsy. Pancreatoduodenectomy was performed. We postulated that the multiple fistulas were formed on the longitudinal fold of Vater's papilla by an ampullary carcinoma, and that the fistulas played a major role in bile drainage. As a result, jaundice was not seen throughout the entire clinical course. We report on the mechanism of fistula formation, with a review of the recent literature.

Membrane responses were recorded from isolated gastric smooth muscle of Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats, using microelectrode techniques. At the age of 68-76 weeks, the blood sugar level was 181 mg/dl in LETO rats and 350 mg/dL in OLETF rats. In both rats, the membrane potential was stable in fundus muscle and spontaneously active with generation of slow waves in antrum muscle. The resting membrane potential was about - 46 mV in fundus and - 55 mV in antrum muscles of LETO rats, and the values were 3-7 mV lower in OLETF rats. The slow waves were generated regularly in LETO rats, while they were irregular and of small amplitude in OLETF rats. Transmural nerve stimulation evoked a cholinergic excitatory junction potential and following inhibitory junction potential in LETO rats, and only an inhibitory junction potential of smaller size was generated in most of OLETF rats. The acetylcholine-induced depolarization was greater in OLETF than in LETO rats. The level of hyperpolarization produced by noradrenaline was similar between OLETF and LETO rats. Thus, the reduction of the resting membrane potential, weakening of spontaneous activity, impairment of cholinergic transmission and cholinergic supersensitivity were associated with hyperglycemia. These alterations were considered due to the development of diabetes mellitus.

Electrical properties of colonic smooth muscle were investigated in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model animal for spontaneous non-insulin-dependent diabetes mellitus (NIDDM), and the results were compared with those obtained from the Long-Evans Tokushima Otsuka (LETO) rat, a control of OLETF rat. At experiments (aged 60-80 weeks), blood glucose level was about 171 mg/dl in LETO rats and 370 mg/dl in OLETF rats. Feces in the colon were restricted to the proximal region in LETO rats and distributed widely in the whole colon in OLETF rats. In both LETO and OLETF rats, the circular smooth muscle strips of the isolated distal colon revealed two types of spontaneous electrical response, slow wave and transient hyperpolarization. The resting membrane potential was smaller in OLETF rats than in LETO rats by about 3 mV, but it was not positively related with the blood glucose level. The amplitude of hyperpolarization produced by noradrenaline (NA) was smaller in OLETF rats than in LETO rats. Transmural nerve stimulation evoked a non-adrenergic, non-cholinergic (NANC) inhibitory junction potential (i.j.p.) in both LETO and OLETF rats; the amplitude of the i.j.p. was smaller in OLETF rats than in LETO rats, while the latency of the i.j.p. was longer in OLETF rats than in LETO rats. Thus, in the distal colon, NIDDM may cause a depolarization of the membrane, an attenuation of NANC inhibitory transmission and a reduction in reactivity of adrenoceptors to NA. These results suggest that the constipation appearing with diabetes mellitus involves dysfunction of both the enteric autonomic nerves and the smooth muscles in the colon.

Electrophysiological experiments were carried out to investigate the prokinetic actions of DQ-2511 on isolated smooth muscle of the guinea pig stomach. DQ-2511 enhanced the myogenic gastric slow waves and cholinergic excitatory junction potential and reduced the frequency of slow waves and the nonadrenergic, noncholinergic, and nonnitrergic inhibitory junction potential, with no significant alteration of the resting membrane potential. The results suggest that the prokinetic actions of DQ-2511 involve excitatory actions directly on smooth muscle and indirectly on cholinergic transmission.

Peroxidation of lipids in serum and tissues of mice placed in low or high levels of oxygen was examined. After exposure to 100% oxygen for 3 h, no significant differences were observed between control and exposed mice. However, exposure to 100% oxygen for 6 h resulted in a decrease in oxygen consumption, an increase in lipid peroxides in tissues and serum, and the formation of hydroxyl radicals in tissues and serum. At low concentrations of oxygen (14% or 16%), a decrease in oxygen consumption, peroxidation of lipids and formation of hydroxyl radicals also were observed. Damage to mice was great with the lower oxygen concentrations of oxygen. There was a close correlation between the consumption of oxygen lipid peroxidation, formation of hydroxyl radicals.