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The aim of the present study was to investigate the influence of an exercise program on neuropeptide concentrations, disease activity, impairments and disabilities in rheumatoid arthritis (RA). Eleven females (median age 60 years, median disease duration 6.5 years, ARA functional classes I or II) exercised 30 min daily for 4 weeks. The urine concentrations of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and neuropeptide Y-like immunoreactivity (NPY-LI) were analyzed 1 week prior to exercise start, at exercise start, after 2 and 4 weeks of exercise, and after a 4-week follow-up period. Measurements of disease activity, aerobic capacity, grip force, limb muscle function, and activities of daily living (ADL) were also undertaken. The results indicate a decrease (md 5.64 pM to md 3.48 pM, P≤0.05) of CGRP-LI concentrations after 4 weeks’ exercise. NPY-LI concentrations remained unchanged, as did disease activity and aerobic capacity. Muscle function and ADL capacity improved significantly (P≤0.05) after the exercise period. Only the improved grip force remained after the follow-up period. In conclusion the results indicate that decreased CGRP-LI concentration, probably reflecting a decreased sympathetic tone, follows physical exercise and suggest that regular physical activity might be important among individuals with RA to maintain a decreased sympathetic tone and less symptoms from their disease. Copyright 1999 Harcourt Publishers Ltd

Over the last decade, several patients afflicted with xerostomia have been treated with acupuncture. Their salivary flow rates increased significantly and the improvement lasted during a long observation period. We also found that the release of several neuropeptides in the saliva of healthy subjects can be increased by acupuncture stimulation. The concentration of vasoactive intestinal polypeptide increased significantly in the saliva of xerostomic patients after acupuncture treatment. The release of the neuropeptide calcitonin gene-related peptide (CGRP) was investigated in the saliva of xerostomic patients in order to elucidate further the mechanisms of the effect of sensory stimulation (acupuncture) on the salivary secretion. CGRP-like immunoreactivity was measured with radioimmunoassay (RIA) before and after a double series of acupuncture treatment, in stimulated saliva of 14 patients who suffered from xerostomia. The results showed that the concentration of CGRP increased significantly (P<0.001) in the saliva of these patients after the end of acupuncture treatment as compared to base-line levels. Taking into consideration the influence of CGRP on the salivary flow, as well as its trophic effect, we concluded that the increased release of CGRP could be one of the factors that affect positively the salivary flow rates of xerostomic patients who were treated with acupuncture.

Indirect immunofluorescence histochemistry and receptor autoradiography were used to study the localization of transmitter-/peptidecontaining neurons and peptide binding sites in the mediobasal hypothalamus in normal rats and in rats treated neonatally with repeated doses of the neurotoxin monosodium-glutamate (MSG). In the arcuate nucleus, the results showed a virtually complete loss of cell bodies containing immunoreactivity for growth hormone-releasing factor (GRF), galanin (GAL), dynorphin (DYN), enkephalin (ENK), corticotropin-like intermediate peptide (CLIP), neuropeptide Y (NPY), and neuropeptide K (NPK). Tyrosine hydroxylase(TH)-, glutamic acid decarboxylase(GAD)-, neurotensin(NT)- and somatostatin(SOM)-immunoreactive (IR) cells were, however, always detected in the ventrally dislocated, dorsomedial division of the arcuate nucleus. In the median eminence, marked decreases in numbers of GAD-, NT-, GAL-, GRF-, DYN-and ENK-IR fibers were observed. The numbers of TH-, SOM-and NPY-IR fibers were in contrast not or only affected to a very small extent, as revealed with the immunofluorescence technique. Biochemical analysis showed a tendency for MSG to reduce dopamine levels in the median eminence of female rats, whereas no effect was observed in male rats. Autoradiographic studies showed high to moderate NT binding sites, including strong binding over presumably dorsomedial dopamine cells. In MSG-treated rats, there was a marked reduction in GAL binding in the ventromedial nucleus. The findings implicate that most neurons in the ventrolateral and ventromedial arcuate nucleus are sensitive to the toxic effects of MSG, whereas a subpopulation of cells in the dorsomedial division of the arcuate nucleus, including dopamine neurons, are not susceptible to MSG-neurotoxicity. The results indicate, moreover that the very dense TH-IR fiber network in the median eminence predominantly arises from the dorsomedial TH-IR arcuate cells, whereas the GAD-, NT-, GAL-, GRF-and DYN-IR fibers in the median eminence to a large extent arise from the ventrolateral arcuate nucleus. Some ENK-and NPK-positive cells in the arcuate nucleus seem to project to the lateral palisade zone of the median eminence, but most of the ENK-IR fibers in the median eminence, located in the medial palisade zone, seem to primarily originate from an area(s) located outside the arcuate nucleus, presumably the paraventricular nucleus. The NPY-positive fibers in the median eminence contain to a large extent immunoreactive dopamine ß-hydroxylase (DBH), and do not arise from the ventromedial arcuate nucleus. SOM-IR cells in the dorsal periventricular arcuate nucleus do not send major projections to the median eminence. The present findings thus show that MSG treatment represents a valuable tool to clarify the organization of chemically identified neuron populations in the arcuate nucleus-median eminence complex and provide further information for understanding the neuroendocrine effects of neonatal MSG treatment.

Neuropeptide Y (NPY), a regulatory peptide in both the central and peripheral nervous systems, has recently been found in neuroendocrine tumors as well as in the bone marrow of rat and certain autoimmune mice, but not in human bone marrow. To investigate a possible role for NPY in the human hematopoietic system, we have prospectively studied NPY-like immunoreactivity in plasma (P-NPY-LI) and NPY mRNA in bone marrow from children with acute leukemia. Northern blot showed high levels of NPY mRNA in bone marrow and peripheral lymphoblasts from children with B-cell precursor leukemia. In situ hybridization showed NPY mRNA in malignant B-cell precursor lymphoblasts. No NPY mRNA was detected in the bone marrow of children with T-cell leukemia. P-NPY-LI was higher (P less than .001) in 51 children with leukemia (200:50 to 385 pmol/L, median:interquartile range) compared to 51 age-matched healthy controls (37:20 to 52 pmol/L). P-NPY-LI was higher (P less than .001) in those with favorable clinical risk classification. Elevated P- NPY-LI, compared with the upper age-adjusted reference limit, was only found in children with B-cell precursor leukemia (31 of 40), whereas all children with B-cell, T-cell, or myeloid leukemia (n = 11) had normal P-NPY-LI (P less than .001). During the 2- to 46-month follow- up, children with elevated P-NPY-LI had better (P less than .001) outcome compared to those with normal P-NPY-LI (79.4% v 34.6% probability for event-free survival).

Using X-ray film autoradiography the distribution of 125I-galanin binding sites was studied in the forebrain of monkey and man. In the monkey a high density was found in all areas of the neocortex, especially layer 4, and in certain subfields in the hippocampal region. Also in the human brain high activity was seen in neocortex, mainly layer 6 and in hippocampal areas, as well as in amygdala, piriform cortex and hypothalamus. These results suggest that the 29-amino acid peptide galanin may be involved in the regulation of higher cortical functions in primates.

We have studied the presence of five neuropeptides in knee joint synovial fluid from either patients suffering from rheumatoid arthritis and pain (n=18) or being subjected to arthroscopy due to meniscal/cruciate ligament injuries (n=13). Radioimmunoassay technique was used for peptide analysis using antisera SP2 against substance P (SP), K12 against neurokinin A (NKA), CGRPR8 against calcitonin gene-related peptide (CGRP), NPY1 against neuropeptide Y (NPY) and VIP2 agains vasoactive intestinal polypeptide (VIP). No SP could be detected, and lower levels of NKA was found in arthritic joints vs controls. CGRP and NPY was found in higher concentrations in arthritic patients vs controls. VIP was found sporadically in both arhtritis and control patients. Our data show some quantitative differences between patients suffering rheumatoid arhtritis and pain, and patients with non-inflammed joints without pain; indicating an involvement of peptidergic fibers in arthritis in humans.

The effect of duodenal perfusion with pancreaticobiliary juice on plasma motilin was investigated in eight fasting subjects. The study was undertaken with recording of gastrointestinal motility, to predict spontaneous fluctuations in plasma motilin levels. Duodenal perfusion with pancreaticobiliary juice or saline at a rate of 5 ml/min for 10 min was performed in random order after the second or third activity front. The 30-min integrated plasma motilin response was significantly greater after perfusion with pancreaticobiliary juice: 1.5 (0.7-2.3) nmol × min/1 (mean and 95% confidence interval), compared with 1.0 (0.5-1.5) nmol × min/l after saline (p < 0.05). Although perfusion with pancreaticobiliary juice was followed by endogenous plasma motilin peaks after about 20 min in six of eight subjects, the mean interval to the next activity front was not significantly different. In conclusion, duodenal perfusion with pancreaticobiliary juice in phase I of the migrating motor complex releases plasma motilin without affecting the fasting motility pattern.

The amount of synovial fluid in small joints which is available for analysis of endogenous compounds is usually very limited and saline washings are therefore commonly required. However, since the washing fluid is not fully recovered and, furthermore, dilutes the synovial fluid in the joint aspirate, the true synovial fluid concentration of a particular substance is unknown. In the present study we validate the use of vitamin B12 (hydroxocobalamin, 1 mg ml-1) as an internal standard to determine this dilution, since its strong red colour lends itself to spectroscopic measurement by a capillary tube system requiring only 3 μl per sample. The absorbance of different dilutions of the stock solutions (25, 33 and 50% vitamin B12 in saline) by saline, plasma and hyaluronan was measured in order to establish the optimal wavelength, the lower limit of detection and the interference by plasma or hyaluronan in the absorbance. Furthermore, the interaction of vitamin B12 in the analyses of interleukin-1β, serotonin and glucose was investigated. The optimal wavelength was found to be 350 nm and the limit of detection 0.5-0.9% dilution of the vitamin B12 solution. Hyaluronan or plasma did not influence the absorbance measurements and the minute interaction of vitamin B12 in the photometric measurements could be compensated for.

Tachykinins are a family of peptides that may be present in and secreted from carcinoid tumours of mid-gut origin. They are likely to play a role in the pathogenesis of, e.g. the flush, dyspnoea and valvular heart disease seen in the carcinoid syndrome. Since tachykinins are secreted from the tumour into the circulation in bursts, coinciding with flushing attacks, and have short half-lives, we anticipated that analysis of 24-h urine excretion of immunoreactive tachykinin metabolites might prove to be a more sensitive and stable parameter for monitoring than tachykinin-like immunoreactivity in plasma. The study included 48 patients hospitalized for treatment of advanced carcinoid tumours and 32 healthy controls. The urine excretion of tachykinin-like immunoreactive metabolites in the carcinoid patients (median 27.5 pmol 24 h-1, interquartile range (IQR) 8.5-51.0 pmol 24 h-1) was significantly (p<0.001) higher than that in the 32 healthy subjects (median 3.0 pmol 24 h-1, IQR 0.9-4.20 pmol 24 h-1). Of the patients, 38 (79%) had elevated 24-h urine excretion of tachykinin-like immunoreactive metabolites while 31 (64%) had elevated plasma concentrations of tachykinin-like immunoreactive metabolites. Of the patients, 27 (56%) had elevated concentrations of tachykinin-like immunoreactive metabolites both in plasma and urine, 12 (25%) had elevated concentrations only in urine excretion, 3 (6%) had elevated concentrations of only plasma tachykinin-like immunoreactive metabolites and 7 (14%) had elevation of neither plasma nor urine concentrations. Analysis by means of different column chromatographic techniques indicated that the immunoreactive material was heterogeneous, with some components co-eluting with oxidized neurokinin A (NKA) and neuropeptide K (NPK). The urine tachykinin-like immunoreactivity correlates well with that of plasma, but is a slightly more sensitive indicator of elevated tachykinin-like immunoreactivity, probably since levels of urine tachykinin-like immunoreactive metabolites reflect the overall amount of the latter secreted into the circulation during 24 h.

Summary: The effects of epithelium removal were studied on the contraction induced by Ca²⁺ in K⁺-depolarizing solution, and by the calcium ionophore A 23187 in guinea-pig isolated tracheal strips. Epithelium removal reduced the maximal response to Ca²⁺ in K⁺-depolarizing solution and caused a significant shift to the right of the Ca²⁺ concentration-response curves. The contraction induced by the calcium ionophore A 23187 (10^-6 M) was also markedly reduced by epithelium removal. These results suggest the occurrence of an epithelium-derived contracting factor. The effects of hexamethonium, atropine, spantide and thiorphan showed that acetylcholine and neurokinins play a minor role in the Ca²⁺-induced contraction. The epithelium-dependent potentiation of the calcium- and of the A 23187-induced contractions was inhibited by an antibody selective for rat calcitonin gene-related peptide (rCGRPα). Therefore, CGRP-like immunoreactive material may be part of the epithelium-dependent contracting factor of guinea-pig trachea. Comparison of concentration-response curves for rCGRPα in epithelium-free and in intact guinea-pig tracheal strips suggests that an epithelium-dependent contracting factor may be mobilized by CGRP. Copyright 1993, 1999 Academic Press

Hypotension is a common and sometimes dangerous side effect of hemodialysis. Its etiology is multifactorial and largely unknown. Earlier studies on the role of endogenous blood pressure regulating agents such as catecholamines and renin have rendered conflicting results. We studied the influence of ultrafiltration and isovolemic hemodialysis separately on the plasma concentrations of the following blood pressure regulating agents: adrenaline, noradrenaline, dopamine, neuropeptide Y, calcitonin gene-related peptide (CGRP), renin (PRA), angiotensin II, vasopressin, aldosterone and Cortisol. During isolated ultrafiltration, plasma levels of two strong vasoconstrictors (noradrenaline and angiotensin II) and one strong vasodilator (calcitonin gene-related peptide, CGRP) increased significantly (noradrenaline 3.24 ± 0.60 nM to 4.31 ± 0.55 nM; p = 0.032, angiotensin II 19.74 ± 3.46 pmol/l to 28.49 ± 7.24 pmol/l; p= 0.047) No symptomatic hypotension occurred. At the end of isovolemic hemodialysis, plasma levels of all the vasoconstricting agents had decreased to pretreatment values, but those of CGRP had continued to rise (from 85.3 ± 17.6 pmol/l to 114.5 ± 25.3 pmol/l, p=0.031). During isovolemic hemodialysis, blood pressure fell to symptomatic levels, but was restored at the end of treatment. The study shows that hemodialysis patients respond to fluid removal by ultrafiltration with an increase in plasma levels of CGRP, noradrenaline and angiotensin II. The net effect is an appropriate vasoconstriction and adequate blood pressure is maintained during isolated ultrafiltration. During hemodialysis, the patients’ blood volumes remained unchanged as evident by a stable hematocrit, the vasoconstrictor hormones returned to normal levels, but in several patients there was a continuous release of vasodilating CGRP. Hypotension, then occurred in these patients due to the imbalance between vasoconstricting and vasodilating factors.

Rats were pretreated with 0.9% NaCl, or 0.1 or 1.0 mg/kg MK-801, an anticonvulsant and a psychotomimetic drug, and 60 minutes later given ECS or sham ECS. After six sessions the animals were sacrificed and neuropeptide Y (NPY-), neurokinin A (NKA-), and calcitonin gene-related peptide (CGRP-) like immunoreactivity (-LI) measured with radioimmunoassays. ECS increased NPY-LI in frontal cortex, striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex and hippocampus. MK-801 increased CGRP in a dose-response manner in frontal cortex, and NKA-LI in occipital cortex. Although the higher MK-801 dose reduced seizure duration by 50%, the ECS induced NPY-LI increase in striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex was not diminished. In contrast, there was a parallel decrease in seizures and NPY-LI and NKA-LI changes in frontal cortex and hippocampus, respectively. Investigation of neuropeptides in brain may contribute to understanding of the mechanisms of action of antide-pressive and antipsychotic treatments and of psychotomimetic drugs.

Abstract: Interleukin-6-like (IL-6-like) immunoreactivity was sought in inflamed and normal human skin using the same immunohistochemical technique as for detection of neuropeptides. Such immunoreactivity was found in dermal and in a few intraepidermal nerve-like fibres in biopsy specimens from inflamed skin from patients with positive epicutaneous patch-test reactions to nickel sulphate, and in skin specimens from patients with atopic dermatitis and prurigo nodularis. However, IL-6-like immunoreactivity was also found in nerve-like fibres in specimens from nonlesional skin. In skin from patients with positive epicutaneous patch-test reactions there was a statistically significantly ( P < 0.01) higher number of IL-6-positive nerve fibres in the epidermis than in normal skin, in contrast to the papillary dermis, in which no difference was found. Moreover, there were clusters of nerve-like fibres with IL-6-like immunoreactivity in the dermis of prurigo nodularis lesions. In these nerve-like fibres, the colocalization of the immunoreactivities for IL-6 and calcitonin gene-related peptide was indicated. Localization of immunoreactivity to nerve-like structures surrounding the eccrine sweat glands indicates that IL-6 is present in autonomic as well as in sensory nerve fibres.

Background: Previous studies suggest that E2 prostaglandins and the microflora may participate in the regulation of endocrine cells and of gastrointestinal cell kinetics. Our aim is to examine the actions of endogenous prostaglandins and of the microflora on gastrointestinal cell proliferation and tissue levels of neuroendocrine peptides. Methods: Germfree and ex-germfree rats were treated with subcutaneous placebo or 1.5 mg/kg indomethacin for 3 days. All rats were labeled with 3H-methyl-thymidine, and biopsy specimens from different parts of the gastrointestinal tract were processed for autoradiography. DNA synthesis was estimated by the labeling index, except in the oxyntic mucosa, where the total number of labeled cells present in 7.5 mm mucosa was used. The concentration of neuroendocrine peptides was determined by radioimmunoassay. Results: In the germfree rat, indomethacin reduced DNA synthesis in the fundus, duodenum, and proximal jejunum (P < 0.05) and the number of villous cells throughout the small intestine (P <0.05). Exposure to microflora increased DNA synthesis in the proximal and distal jejunum, ileum, and colon (P < 0.05 versus germfree controls) and the number of crypt cells in the distal small intestine and colon (P < 0.05) and reduced the number of villous cells in the small intestine (P < 0.05) but did not affect tissue concentrations of neuroendocrine peptides. Indomethacin increased the concentration of somatostatin in the stomach, duodenum, and colon of germfree rats (P < 0.001), the concentration of calcitonin gene-related peptide (CGRP) and enteroglucagon in the proximal and distal jejunum and ileum (P < 0.001), and the concentration of glucagon in the colon (P <0.05). The concentrations of somatostatin, CGRP, and glucagon were lower in indomethacin-treated ex-germfree rats than in indomethacin-treated germfree rats (P < 0.01). Conclusions: Indomethacin selectively reduced DNA synthesis in the upper gastrointestinal tract of germfree rats, indicating a basal stimulatory role for endogenous prostaglandins on cell proliferation. Endogenous prostaglandins modulate synthesis or release of gastrointestinal neuroendocrine peptides. Somatostatin may mediate indomethacin-induced reduction of DNA synthesis. The microflora stimulates cell proliferation and influences tissue levels of neuroendocrine peptides in a manner opposite to that of indomethacin.

Neuropeptide Y (NPY) was investigated as a possible tumor marker in pediatric patients with tumors of the sympathetic nervous system. Seven patients with neuroblastoma, 3 patients with ganglioneuroblastoma, and 2 with ganglioneuroma, were compared with 12 matched healthy controls and 34 tumor controls. NPY-like immunoreactivity (NPYLI) was analyzed in extracted plasma using a competitive radioimmunoassay. At diagnosis, plasma NPYLI was significantly increased (p < .001) in the neuroblastoma patients (352 ± 99 pM; mean ± SEM) when compared with healthy controls (36 ± 4 pM) and tumor controls (30 ± 2 pM). Ganglioneuroblastoma and ganglioneuroma patients had lower levels (57 ± 8 pM) than neuroblastoma patients but still significantly higher than the controls. In all patients with sympathetic tumors, the NPYLI level was decreased after treatment. Five neuroblastoma patients relapsed; all had increasing NPYLI levels. In 3 of these patients, increasing NPYLI was the first sign of relapse. Plasma NPYLI correlated well to urinary levels of homovanillic acid. NPY in plasma (NPYLI) may be a clinically useful marker of pediatric neuroblastoma for diagnosis and differential diagnosis. NPYLI correlates well with the clinical course and can be the first sign of relapse. Plasma determinations of NPYLI make it possible to monitor rapid alterations of disease.

Summary— We have studied the contribution of epinephrine to experimentally induced urethral inflammation in the rat. Inflammation was induced by inserting latex strips into the urethra. The effects of various experimental procedures were assessed according to a 4-point scale based on histological findings. The results showed that 0.5 mg/kg epinephrine decreased the severity of catheter-induced urethral inflammation. This effect was blocked by the a2-adrenergic agonist, yohimbine, but not by a1(prazosin), ß1(M32 MTC), or ß2(butoxamine) antagonists. The results suggest that the suppressive effect of epinephrine is mediated by action at the a2adrenergic receptor.

Hypertension often occurs with fluid overload. The most common mechanism is considered to be mediated by increased cardiac output. Hemodialysis (HD) patients frequently have large amounts of fluid overload. Neuropeptide Y (NPY) is activated by stress and contributes to hypertension and heart failure. We speculated that NPY may be released by the stress of fluid overload and, by its vasoconstrictor effect, may contribute to hypertension and heart failure. Plasma levels of NPY and other vasoconstrictors were studied in 20 HD patients with varying degrees of fluid overload, and the relationship of NPY plasma levels to blood pressure was analyzed. The plasma concentrations of NPY correlated with the degree of fluid overload (r = 0.89; P < 0.0001) and the mean arterial blood pressure (r = 0.85; P < 0.0001). Seven patients had fluid overload of greater than 6% of body weight. They had higher blood pressures and higher plasma concentrations of NPY than 13 HD patients with less than 5% of fluid retention (systolic blood pressure, 179+/-8.2 v 145+/-3.7 mm Hg, P = 0.007; NPY, 61+/-4.6 v 26.8+/-2.7 pmol/L, P < 0.001). In stepwise multiple regression analysis, NPY alone explained blood pressure elevation when analyzed with fluid overload and angiotensin II, renin, noradrenaline, and adrenaline levels. We hypothesized that fluid overload in dialysis patients is a stress- inducing state that activates the sympathetic nervous system and releases the vasoconstrictor NPY. The resulting inappropriate vasoconstriction may contribute to volume-induced hypertension and heart failure in a vicious cycle. We conclude that determination of plasma NPY levels may be useful as a marker of the clinical threat of overhydration. (Am J Kidney Dis 1998 May;31(5):803-8)

Abstract. Vasoactive intestinal peptide (VIP) is a potent stimulant of duodenal HCO3−secretion and may, like prostaglandins, have a stimulatory role in the local duodenal HCO3−response to luminal HCl. Using a proximal duodenal loop in conscious rats, we examined the local luminal release of HCO3−. VIP and prostaglandin (PG) E2in response to increasing concentrations of HCl (0.01–150 mmol l−1), perfused for 5 min at 60‐min intervals. HCO3−and PGE2were detected in all basal saline perfusate effluents, and were increased in a concentration‐dependent manner by all acid concentrations tested. VIP was increased in a concentration dependent manner from pH 3. Exogenous VIP did not affect the basal luminal output of PGE2, or vice versa. Inhibition of prostaglandin synthesis by indomethacin augmented the HCl‐stimulated luminal release of VIP, as well as the HCO3−response to exogenous VIP. The results are in agreement with previous studies, demonstrating that PGE2is an important regulator of the duodenal HCO3−response to HCl in the rat. In addition, prostaglandins may negatively modulate the release of VIP from local VIPergic neurones, as well as the HCO3−secretagogue effect of VIP. Released VIP may contribute to the HCO3−response at pH ≤ 3.

The use of a somatostatin analogue (SMS 201-995) has greatly facilitated the treatment of patients with the midgut carcinoid syndrome. Clinical studies have shown that SMS reduces the peripheral levels of tumour-produced serotonin (5-HT) and tachykinins, e.g. neuropeptide K (NPK), basally and after pentagastrin provocation. Some studies have indicated an inhibitory effect of SMS on tumour cell growth as well. In the present study we have investigated the effects of SMS on four different human midgut carcinoid tumours maintained in long term culture. Media levels of 5-HT and NPK-LI in tumour cell cultures decreased rapidly during incubation with SMS (10(-8)-10(-10) M) in all four tumours studied without evidence for tachyphylaxis (up to 6 weeks observation period). SMS treatment (10(-8) M) during 4 days reduced the media concentrations of 5-HT by 56%, while the intracellular contents of 5-HT were decreased by 27% indicating dual inhibitory effects on synthesis and secretion of 5-HT from tumour cells. The DNA contents of cultures were not affected by SMS (10(-8) M or 10(-10) M) treatment for 4 or 14 days. When tumour cell cultures were challenged with isoprenaline (IP) (10(-6) M) no reduction of the IP induced release of 5-HT could be detected after pretreatment of tumour cell cultures with SMS (10(-8) M) for 1 h, 4 h or 4 days. These studies provide evidence for a direct action of the somatostatin analogue on midgut carcinoid tumour cells, reducing both synthesis and secretion of hormones from tumour cells. This effect appears not to be related to inhibition of tumour cell growth. The inhibition of 5-HT secretion from tumour cells by SMS seems to operate via a second messenger system different from the one mediating the beta-adrenoceptor stimulated release of 5-HT.

We have investigated the effect of histamine2-receptor blockade on gastric carcinoid formation inMastomys, a rodent prone to develop gastric carcinoids. During long-term treatment (8–24 weeks) with loxtidine, a 3–5 fold increase in plasma gastrin levels was observed. Oxyntic mucosal histamine and histidine decarboxylase activity were increased 2 times and 4–10 times respectively in loxitidine-treated animals, as compared to controls. An increase in oxyntic mucosal thickness was also noted in all treated animals, while gross tumors were only observed in animals treated for 24 weeks. Immunocytochemical analysis of treated animals revealed a marked proliferation of chromogranin-positive cells in the oxyntic mucosa. These cells were identified as ECL cells because they were labeled by histamine antibodies, but not by gastrin-, somatostatin-or serotonin-antibodies. Hyperplasia of endocrine cells was noted after 8 weeks of treatment, while dysplastic lesions were seen after 16 weeks and the first micro- or macrocarcinoids after 24 weeks of treatment. No tumors, or hyperplastic changes, were observed in control animals. The results demonstrate that histamine2-receptor blockade significantly enhances the development of gastric carcinoids inMastomys and suggest that hypergastrinemia may be important for the development of these tumors.

Tumour cells from a hepatic metastasis of a midgut carcinoid tumour were studied during 240 days of culture. A cell line could not be established, but the cells regularly formed large clusters and islets. The spontaneous release of serotonin (5-HT) and neuropeptide K-like immunoreactivity from cultures were followed. The amine and the peptide levels were unstable without evident covariation. The response to stimulation with noradrenaline and isoprenaline was studied during the culture period. The tumour cells released 5-HT selectively at stimulation with isoprenaline. This responsiveness also showed considerable variation with long periods of quiescence. Ultrastructurally the tumour cells showed a certain degree of polarization with apical microvilli and a supranuclear Golgi apparatus. When studied by confocal laser scanning the tumour cells were demonstrated to be cylindrical in shape with a cytoplasmic attachment to the matrix.

Assay of regulatory peptides has an established role in the diagnosis and management of several peptide-producing tumours, including endocrine pancreatic tumours, carcinoid tumours, medullary thyroidea carcinomas, pheochromocytomas, and neuroblastomas. Proper sample handling (rapid cooling and freezing) is important since most regulatory peptides (except gastrin and pancreatic polypeptide) are labile in plasma. The immunoassay should preferably have broad specificity for the peptide family to be analysed since endocrine tumours may result in elevated concentrations of different spectra of the peptides in individual patients. From the analytical point of view, this is in contrast with the preferences of the physiologist who is usually interested in measuring the concentration of a single member of the peptide family with as high specificity as possible.

Treatment with the somatostatin analogue octreotide, SMS 201-995 (Sandostatin), has been carried out in a series of 23 patients with malignant midgut carcinoid tumours. the patients received initially 50 μg twice a day for six months, thereafter a median of 100 pg twice daily. Six of 22 evaluable patients (28%) showed objective tumour response lasting for 6 to 30 months. Stable disease was observed in 8 of the 22 patients (36%) and progressive disease in a further 8 patients (36%). A subjective response with decrease of diarrhoea or flushing was noted in 11 out of 22 patients (50%). Two out of 6 patients with objective response demonstrated a significant decrease of tumour size lasting for 6 and 30 months respectively. in order to maintain the clinical response, the dose had to be increased in all 6 responders. the adverse effects included development of diabetic blood glucose levels in 8 out of 22 patients (36%). Albumin-modified serum calcium levels were significantly reduced after treatment with octreotide 50 μg twice a day. One patient developed symptoms of hypocalcemia which was reversed by supplementation with calcium and D-vitamins. the somatostatin analogue SMS 201-995 has a beneficial effect in the treatment of patients with the carcinoid syndrome. However, the precise role of the drug in the long-term management of these patients has to be further investigated.

The aim of this study was to assess the effect of blocking the axonal transport of sensory neuropeptides, by local injection of colchicine at pelvic ganglia level, on the sensory and efferent functions mediated by capsaicin-sensitive primary afferent neurons innervating the rat urinary bladder. Bilateral injection of colchicine in the prostatic tissue underneath the pelvic ganglia of male rats induced a time-dependent reduction (maximal at 72 h, 100% reduction) of the in vitro contraction of the bladder strips induced by capsaicin (1 μM). The response to electrical field stimulation was also reduced, although to a lesser extent. The direct contractions induced by substance P (100 nM) or KCl (80 mM) were not affected by colchicine pretreatment. In vivo, perigangliar injection of colchicine (72 h before) greatly increased bladder capacity, and reduced the amplitude of micturition contractions and micturition frequency. Capsaicin-induced plasma protein extravasation was abolished in the urinary bladder and reduced in the distal, but not the proximal ureter of colchicine-treated rats. Topical application of capsaicin onto the urinary bladder or onto the stomach induced a cardiovascular pressor reflex in urethane-anaesthetized, spinalized rats. Colchicine pretreatment reduced (by about 50%) the pressor response elicited by chemonociceptive stimulation of the bladder but not that arising from the stomach.

Like medicine, statistics is an art requiring a good portion of judgement and common sense as well as formal skills. It is therefore not always possible to claim superiority of one statistical technique over another in a given situation. However, several studies have indicated that about half of all biomedical research papers contain obvious statistical errors, several of which may be corrected by proper instructions to authors or by specific statistical reviewing of the papers - hence the present guidelines.

It is generally believed that diabetic neuropathy is due to chronic hyperglycaemia. However, experience from insulinoma patients and experimental studies show that hypoglycaemia may also cause neuropathy. Accordingly, the plantar nerves of diabetic eu‐/hypoglycaemic BB/Wor rats treated with insulin implants exhibit a distinct neuropathy. To what extent hypoglycaemic neuropathy affects axon terminals in skin and muscle is unknown. In the present study we examine the occurrence of epidermal axon profiles and the neuropeptide calcitonin gene‐related peptide (CGRP) in plantar skin, and of end plate axon terminals in a plantar muscle of diabetic BB/Wor rats subjected to long periods of hypoglycaemia. The number of protein gene product‐immunoreactive axon profiles was found to be normal in heel skin biopsy specimens from eu‐/hypoglycaemic rats, but many profiles were short and thin. The content of CGRP in the skin biopsy samples was significantly below normal. After staining with antibodies against the vesicular acetyl choline transporter protein, the occurrence of end plate axon terminals was significantly reduced in sections from the flexor hallucis brevis muscle of eu‐/hypoglycaemic rats. Moreover, the end plate axon terminals tended to be abnormally small in these rats. We conclude that the hypoglycaemic neuropathy seen in plantar nerve trunks of diabetic BB/Wor rats treated with insulin implants is accompanied by mild alterations in the epidermal innervation of plantar skin and a more obviously abnormal nerve terminal pattern in plantar muscle.

To investigate the hypothesis that calcitonin gene-related peptide (CGRP), a potent vasodilator, is an important physiological defence against fluid overload, plasma CGRP concentrations were measured in various degrees of fluid overload in 26 haemodialysis patients, for whom diuresis, mediated by atrial natriuretic peptide (ANP), is not a possible defence mechanism. Plasma CGRP concentrations were positively correlated with the degree of fluid excess (r= 0·815, p = 0·0001) and were significantly higher in 5 patients with severe fluid overload than in those less severely affected (143 [SE 14] vs 52 [11] pmol/l; p<0·001). CGRP may be an effective defence against complications of fluid overload since it can increase capitance by vasodilatation.