Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of the brain-gastrointestinal polypeptide neurotransmitters bombesin, substance P, neurotensin, and somatostatin-14 on cytotoxicity of peripheral blood mononuclear cells against K-562 and CaCo-2 tumour cells were investigated. Bombesin significantly stimulated cytotoxicity against CaCo-2 target cells (10(-12), 10(-10) M and 10(-6) M) and against K-562 target cells (10(-12) and 10(-10) M) in the short 4 hour assay. Substance P showed a tendency to stimulate cytotoxicity at higher concentrations but the changes observed did not reach significance because of large inter-individual variation of responsiveness. Neurotensin did not influence cytotoxicity against either target cell lines. Somatostatin was found to have no influence on cytotoxicity of peripheral blood mononuclear cells but was the only peptide tested which markedly increased chromium release by target cells alone. These findings support the idea that brain-gastrointestinal neuropeptides can play a part in tumour cytotoxicity.
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PMID:Neuropeptide regulation of cell-mediated cytotoxicity against human tumor cells. 170 Dec 25

Hypothalamic tissue levels of nine regulatory peptides (bombesin, calcitonin gene-related peptide [CGRP], galanin, neuromedin B, neuropeptide Y [NPY], neurotensin, somatostatin, substance P, and vasoactive intestinal peptide [VIP]) were compared in Aston obese diabetic (ob/ob) and lean (+/?) mice aged 4, 16, and 28 weeks. Neurotensin concentrations were significantly lower in ob/ob mice than in lean mice, with a 20% reduction (P = .03) in the whole hypothalamus at 4 weeks of age, a 24% reduction (P = .009) in the lateral hypothalamus at 16 weeks, and a 50% reduction (P = .0007) in the central hypothalamus at 28 weeks of age. Apart from a 42% increase in vasoactive intestinal peptide concentrations in the central hypothalamus of ob/ob mice at 28 weeks (P = .02), levels of the other eight peptides examined did not differ significantly between obese and lean groups. Neurotensin is known to cause anorexia and increased energy expenditure when injected into the central hypothalamus. Reduced hypothalamic neurotensin concentrations may reflect reduced neurotensinergic activity, which might contribute to hyperphagia and decreased energy expenditure, two major defects that contribute to obesity and diabetes in the ob/ob syndrome.
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PMID:Reduced hypothalamic neurotensin concentrations in the genetically obese diabetic (ob/ob) mouse: possible relationship to obesity. 194 36

The distribution and morphology of intestinal endocrine cells was investigated in the mucosa of pelvic ileal reservoirs using immunocytochemical methods. Endoscopic biopsies were obtained from 15 patients after the construction of a modified J-pouch. The mucosa of the reservoir showed a variable degree of colonic metaplasia in all cases. No relevant quantitative variations of gut endocrine cells were detected, as revealed by immunostaining for the general marker, chromogranin, compared with normal ileal mucosa. Immunostaining for different peptide-containing cells resulted in normal number and morphology of serotonin, enteroglucagon, peptide tyrosine-tyrosine, and somatostatin-containing cells. Neurotensin cells were less numerous than in normal mucosa. The role played by gastrointestinal hormones in the adaptive response of the intestine to pouch construction is, presently, unclear. Further studies involving measurements of fasting and meal-stimulated levels of gut hormones in pouch patients might clarify this aspect.
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PMID:Immunocytochemical study of endocrine cells in pelvic ileal reservoirs. 197 12

Two calcium-activated neutral proteases (CAPI & II) were purified from human skeletal muscle by anion exchange, gel filtration and affinity (antipain-Sepharose and Blue Ultrogel A4R) chromatography. The enzymes were homogenous as judged by polyacrylamide gel electrophoresis, and have similar properties with the exception of the Ca2+ concentration required for optimum activity (CAP I = 0.1 mM; CAP II = 1 mM). Both enzymes hydrolysed a wide variety of neuropeptides. In six cases, the products were separated and identified by hplc and amino acid analysis. Neurotensin was hydrolysed at Tyr3-Glu4; dynorphin1-13 at Arg8-Arg9; LH-RH at Gly6-Leu7; CCK-8 at Phe8-NH2, substance-P at Met10-NH2; somatostatin at Thr10-Phe11. Although differences in the rates of neuropeptide degradation were noted for the two CAP's the specificity was the same for these six peptides. It is suggested that conformational requirements may be more important than side chains adjacent to the cleavage site in directing the specificity of CAP.
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PMID:Specificity of neuropeptide degradation by two calcium-activated neutral proteases from human skeletal muscle. 241 Jul 57

The regional distribution and relative frequency of argyrophil cells, and of cells immunoreactive for 5-hydroxytryptamine (5-HT), substance P (SP), somatostatin, glicentin, glucagon, bovine pancreatic polypeptide (BPP), gastrin, leucine-enkephalin, gastric inhibitory polypeptide (GIP), cholecystokinin, secretin, motilin, and neurotensin were studied in 9 segments from the gastrointestinal tract of cows (greater than 1 year old) and calves (less than 3 months old). Argyrophil cells, 5-HT-immunoreactive cells, and somatostatin-immunoreactive cells were distributed throughout the gastrointestinal tract, whereas the other immunoreactive cells were more restricted in distribution. Most endocrine cells were more numerous in the calf than in the cow. This feature was most conspicuous in the abomasum. In the abomasum, argyrophil cells in the cow and calf and 5-HT-immunoreactive cells in the calf were found predominantly in the fundic region, whereas somatostatin-immunoreactive cells and gastrin-immunoreactive cells in the cow and calf and 5-HT-immunoreactive cells in the cow were most numerous in the pyloric region. Substance P-, glucagon-, BPP-, and leucine-enkephalin-immunoreactive cells were rarely detected. In the small intestine, argyrophil cells, 5-HT-, SP-, somatostatin-, gastrin-, GIP-, cholecystokinin-, secretin-, and motilin-immunoreactive cells were most numerous in the duodenum. Neurotensin-, glicentin-, glucagon-, and BPP-immunoreactive cells were detected with the highest frequency in the ileum. In the large intestine, argyrophil cells and 5-HT-, glicentin-, BPP-, somatostatin-, glucagon-, and SP-immunoreactive cells occurred with the highest frequency in the rectum.
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PMID:Histologic and immunocytochemical study of endocrine cells in the gastrointestinal tract of the cow and calf. 241 Nov 74

The presence and distribution of regulatory peptides in nerves and endocrine cells of the stomach, intestine and rectum of a urodele amphibian, the mudpuppy, Necturus maculosus, was studied immunohistochemically in sections or whole-mount preparations of the gut wall. The effect of the occurring peptides on gut motility was studied in isolated strip preparations of circular and longitudinal smooth muscle from different parts of the gut. Bombesin-, neurotensin-, substance P- and VIP-like immunoreactivity was present in abundant nerve fibres in the myenteric plexus of both stomach, intestine and rectum. Single fibres or bundles were present in the circular muscle layer and in a well-developed deep muscular plexus in the intestine and rectum. Immunoreactive nerve cells were found in the myenteric plexus of the stomach, intestine (neurotensin only) and rectum. Gastrin/CCK-like immunoreactivity was observed only in a few fibres in stomach and rectum. Endocrine cells containing bombesin-, met-enkephalin-, gastrin/CCK-, neurotensin-, somatostatin- or substance P- like immunoreactivity were present in the mucosa. The effect of bombesin was an inhibition of the rhythmic activity in circular muscle preparations and in longitudinal muscle from the rectum, while longitudinal muscle from the stomach usually responded with a weak increase in tonus. Neurotensin, like-bombesin, was inhibitory on the spontaneous rhythmic activity of circular muscle throughout the gut, while the effect on longitudinal muscle was an increase in tonus. Met-enkephalin and substance P increased the tonus of all types of preparations, and often, in addition, initiated a rhythmic activity superimposed on this maintained tonus. VIP had a general inhibitory effect on the preparations, decreasing tonus and/or abolishing rhythmic activity. It is concluded that bombesin-, neurotensin-, substance P- and VIP-like peptides are present in nerves throughout the urodele gut and may have physiological functions in regulating the motility of the gut. The gastrin/CCK-like peptide present in nerves of the stomach and rectum may affect the function of these parts of the gut. The regulatory peptides present in endocrine cells may, perhaps with the exception of the somatostatin-like peptide, affect the motility humorally.
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PMID:Neuropeptides in the gastrointestinal canal of Necturus maculosus. Distribution and effects on motility. 241 14

The potency of several peptides and drugs as histamine liberators was assessed using the rat isolated hind limb preparation. Neurotensin (NT) and compound 48/80 (C48/80) were effective in concentrations as low as 10(-9) M and 10(-8) M, respectively. Threshold concentrations of vasoactive intestinal peptide (VIP) and substance P (SP) varied between 5 X 10(-7) to 5 X 10(-6) M while somatostatin (SS) was barely active at 6 X 10(-6) M. No histamine release could be detected following the use of high concentrations of thyrotropin releasing hormone (TRH) (6 X 10(-6) M), dynorphin (DYN) (6 X 10(-6) M) bradykinin (BK), des-Arg9-BK or bombesin (BB) (at 10(-5) M). Poly-L-Lysine and the calcium ionophore A23187 were about 100 times less active than NT. Concanavalin A (Con A) was inactive at 10(-6) M. These results indicate that NT is more potent (on a molar basis) as histamine liberator in the rat hind limb preparation (which contains a large population of cutaneous and subcutaneous mast cells) than any of the other compounds tested. Histamine release by NT was inhibited by preexposure of the rat hind limb mast cells to a high concentration of SP (1.5 X 10(-6) M). This result adds further support to the hypothesis suggesting that NT and SP might share a common mechanism of action and/or act through common receptors at least in rat mast cells.
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PMID:Potency of various peptides as histamine liberators in the rat hind limb. 241 86

The effects of the putative neurotransmitters acetylcholine, adrenaline, adenosine, ATP, bombesin, 5-hydroxytryptamine, met-enkephalin, neurotensin, somatostatin, substance P and VIP have been investigated in the perfused intestine of the cod, Gadus morhua. The presence and distribution of the different types of nerves was investigated with immunohistochemistry and Falck-Hillarp fluorescence histochemistry. A spontaneous rhythmic activity of the perfused preparations usually occurred within a few minutes from the start of the experiment. This activity was diminished or abolished by addition of atropine, methysergide or tetrodotoxin to the perfusion fluid. Acetylcholine, 5-hydroxytryptamine or substance P caused a contraction of the intestinal wall. The response to acetylcholine was blocked by atropine but not by tetrodotoxin, while the response to 5-hydroxytryptamine was blocked by methysergide and usually also by tetrodotoxin. This indicates that the effect of acetylcholine is direct on the muscle cells, while the effect of 5-hydroxytryptamine may be at least partly via a second neuron. All adrenergic agonists (adrenaline, isoprenaline and phenylephrine) had a dominating inhibitory effect on the intestine. Experiments with antagonists showed that the inhibition is due to stimulation of both alpha-adrenoceptors and beta-adrenoceptors. ATP, adenosine and somatostatin also caused a relaxation of the intestinal wall, often followed by a contraction. Met-enkephalin produced variable responses, either a relaxation, a contraction or both. Bombesin caused a weak inhibition, if anything. Neurotensin and VIP did not visibly affect the intestinal motility. 5-HT-, substance P- and VIP-like immunoreactivity and catecholamine fluorescence were observed in the myenteric plexus, submucosa and muscle layers in all parts of the intestine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neurotransmitters in the intestine of the Atlantic cod, Gadus morhua. 241 59

This study reports on a difference in the inhibitory action of the neuropeptides somatostatin and Met-enkephalin on acetylcholine (ACh) release from myenteric plexus-longitudinal muscle strips of guinea pig small intestine. Met-enkephalin (8.7 X 10(-8) M) inhibited ACh release evoked by either substance P (3.7 X 10(-8) M) or neurotensin (7.5 X 10(-11) M), and this inhibition could be reversed by naloxone (5 X 10(-8) to 5 X 10(-5) M). Neurotensin-induced ACh release was also sensitive to the inhibition by somatostatin. However, when tested in a dose range from 6.1 X 10(-8) to 6.1 X 10(-6) M, somatostatin was ineffective in reducing the efflux of ACh evoked by substance P. These observations provided evidence to support the view that inhibitory peptidergic neurons within the myenteric plexus modulate the activity of cholinergic neurons with a high degree of specificity and that both somatostatin and Met-enkephalin have distinct neuromodulatory functions in the gut.
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PMID:Inhibitory peptidergic neurons: functional difference between somatostatin and enkephalin in myenteric plexus. 241 98

Effects of hormonal peptides on inflammation were investigated in normal rats receiving injections of urate crystals into the hindpaw. Beta endorphin, somatostatin and alpha melanocyte stimulating hormone injected along with urate crystals produced diminished swelling. Neurotensin and substance P produced increased swelling. Intramuscular calcitonin inhibited inflammation. In rats made deficient in essential fatty acids, thereby becoming deficient in prostaglandins, beta endorphin nullified the proinflammogenic activity of prostaglandin E2. A hypothesis is proposed that modification of inflammation by neuropeptides is part of the continuum of inflammation-regeneration, a generalized host defense mechanism against noxious stimuli.
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PMID:Effects of peptide hormones in urate crystal inflammation. 241 5


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