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)

Melanin concentrating hormone (MCH) is a heptadecapeptide isolated from chum salmon (Oncorhynchus keta) pituitaries. The peptide has been isolated from whole brain extract at a low yield of 1.2 micrograms/1300 brains. MCH activity in the hypothalamus was characterised by in vitro scale bioassay and radioimmunoassay. Specificity of these assay systems was examined with neurotransmitters such as epinephrine, norepinephrine, and dopamine, hypothalamic hormones such as somatostatin, isotocin, Arg-vasotocin, oxytocin, and Arg-vasopressin, and salmon prolactin and its chymotryptic peptide or salmon PRL176-187. Among them only salmon PRL176-187 exhibited weak activities in both assays. The neurotransmitters were 10(4) to 10(5) times less potent than MCH in the bioassay. MCH concentrations in a pituitary and a hypothalamus were estimated as 5300 +/- 750 ng (ca. 106 micrograms/g) and 48 +/- 9.5 ng (ca. 1.6 micrograms/g), respectively, by radioimmunoassay. Lysyl endopeptidase digestion of the hypothalamic extract resulted in a significant increase of biological activity as well as of immunoreactivity. Gel filtration of the hypothalamic extract and subsequent enzymatic digestion revealed that the fractions at higher molecular weight were contributory to the increase in the activities.
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PMID:Characterization of melanin concentrating hormone in teleost hypothalamus. 288 42

The pathophysiological, biochemical, histological, ultrastructural, and immunohistochemical characters of a case of malignant pancreatic islet cell tumor with watery diarrhea syndrome were carefully investigated. Four hormones or mediators--somatostatin (SST), vasoactive intestinal peptide (VIP), serotonin, and prostaglandin E--were markedly elevated in the circulation. The diagnosis was further confirmed by exploratory laparotomy and autopsy. The contents of SST and VIP in tumor tissues were very high. Gel chromatography of tumor extract revealed single peaks for both SST and VIP. Immunohistochemical studies of tumor tissues showed numerous immunoreactive cells to anti-SST, moderate amount of VIP-positive cells, and a few hCG-, insulin-, and glucagon-positive cells. In conclusion, this is an unusual case of Verner-Morrison syndrome in which three kinds of bioactive hormones or mediators were simultaneously secreted; peptides, amine, and prostaglandin.
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PMID:Watery diarrhea syndrome caused by multihormonal malignant pancreatic islet cell tumor secreting somatostatin, vasoactive intestinal peptide, serotonin, and prostaglandin E--a clinicopathological, biochemical, immunohistochemical, and ultrastructural study. 288 47

Variations in the concentrations of plasma and pituitary GH were determined in ducks for 66 and 87 days after hatch, and compared with somatostatin-like immunoreactivity (SLI) in the plasma, hypothalamus and neural lobe. Plasma GH levels gradually decreased during growth, while pituitary GH content increased. The concentration of pituitary GH increased during the first 3 weeks of age and remained relatively constant thereafter. The decline in plasma GH concentration was paralleled by a similar fall in the level of plasma SLI. While the content of hypothalamic SLI increased during development, the SLI concentration was maximal at 14 days of age and lowest in adults. The content and concentration of SLI in the neural lobe, in contrast, increased progressively during development. Gel filtration of hypothalamic and neural lobe extracts demonstrated that both young and older birds had two main peaks of SLI, corresponding to somatostatin-14 and somatostatin-28, and a third, larger form. The elution pattern of plasma SLI was similar in young and older birds and was principally composed of a large molecular species ('big' somatostatin), although an additional small peak eluting between somatostatin-28 and somatostatin-14 was eluted from a large pool of plasma from 90-day-old ducks. These results suggest that increased plasma GH levels in young birds do not result from a hypothalamic somatostatin deficiency nor from variations in molecular forms of SLI, and that the age-related decline in plasma GH concentration is not due to a deficiency in pituitary GH content. The decline in the circulating GH level during growth is probably due to an increase in hypothalamic somatostatin release.
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PMID:Somatostatin-like immunoreactivity in duck plasma, hypothalamus and neural lobe during post-hatch growth: comparison with plasma and pituitary growth hormone concentrations. 288 70

Pancreatic somatostatin-like immunoreactivity (SLI), immunoreactive insulin (IRI) and glucagon-like immunoreactivity (GLI) were measured during growth in ducks. The content of each hormone increased progressively but at different rates in the dorsal, ventral and splenic lobes of the pancreas. In the almost fully grown duck, the splenic lobe contained 80 and 63% of the total content of GLI and SLI respectively but low levels of IRI (23%), which were highest in the dorsal lobe (53%). In contrast to the hormonal content, only total GLI concentrations increased during development, the SLI concentrations remaining stable and IRI concentrations declining during growth. Gel filtration of pancreatic extracts indicated that most of the SLI in the pancreas of young and adult birds was somatostatin-14, although somatostatin-28 was present in the ventral lobe of young birds and larger molecular forms were present in the ventral and dorsal lobes. These changes in pancreatic hormonal content and concentration are dissimilar to age-related changes in SLI, GLI and IRI previously observed in the plasma of ducks. Plasma levels of pancreatic hormones may thus be controlled by hormonal and/or neutral factors during post-hatch growth.
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PMID:Pancreatic somatostatin, glucagon and insulin during post-hatch growth in the duck (Anas platyrhynchos). 288 71

To structurally characterize the somatostatin receptor in the anterior pituitary, the chemical cross-linking reagent N-5-azido-nitrobenzoyloxysuccinimide was used to attach covalently [125I-Tyr11]somatostatin-14 to its receptor in pituitary membranes. Rat anterior pituitary membranes were incubated with [125I-Tyr11]somatostatin-14, washed, and then treated with 100 microM cross-linker, which was activated by exposure to UV light. Gel electrophoresis followed by autoradiography revealed a broad band centered at 88,000 mol wt. The appearance of this band was unaffected by dithiothreitol. Competitive inhibition of binding by unlabeled somatostatin resulted in a parallel inhibition of labeling of the 88,000 mol wt protein. The addition of guanine nucleotides in concentrations that inhibit binding similarly inhibited cross-linking. The cross-linked membranes were solubilized in Zwittergent 3-12, a nondenaturing detergent, and the glycosylation pattern of the labeled protein was investigated by incubation with various lectins coupled to agarose. The cross-linked protein was selectively adsorbed by wheat germ agglutinin, and this interaction was blocked by the addition of N,N',N"-triacetylchitotriose, indicating that the rat anterior pituitary somatostatin receptor is a glycoprotein containing polymeric beta-1-4 linked N-acetylglucosamine groups. The results of this study show that the rat anterior pituitary somatostatin receptor is a glycoprotein of 88,000 mol wt containing no disulfide-linked subunits.
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PMID:Structural characterization of the somatostatin receptor in rat anterior pituitary membranes. 288 81

Calcitonin is secreted by the C cells of the thyroid in response to a raised serum calcium, and acts on bone to lower serum calcium. The C cells have specific receptors for the dihydroxymetabolite of vitamin D3, 1,25(OH)2D3. Moreover, calcitonin stimulates the synthesis of 1,25(OH)2D3 in the kidney. Parathyroid hormone (PTH), the third calciotrophic hormone, is also trophic to the renal synthesis of 1,25(OH)2D3, and in turn 1,25(OH)2D3 inhibits PTH gene transcription and synthesis. We report here the marked inhibition of calcitonin gene transcription by the injection of physiologically relevant doses of 1,25(OH)2D3 to normal rats that did not raise serum calcium. Calcitonin mRNA levels after 100 pmol 1,25(OH)2D3 decreased to 6% of basal at 6 h and 4% at 48 h, and a dose response showed a marked effect even after 12.5 pmol 1,25(OH)2D3, with no appreciably greater effect with larger doses (up to 200 pmol). Control genes, actin, thyroglobulin (thyroid follicular cells), somatostatin (thyroid C-cells) were not affected by 1,25(OH)2D3. Gel blots showed that 1,25(OH)2D3 decreased calcitonin mRNA levels without any change in its size. In vitro nuclear transcription showed that 1,25(OH)2D3-treated (100 pmol) rats' calcitonin transcription was 10% of control, while thyroglobulin and actin were 100%. We propose that calcium is the major regulator of PTH and calcitonin secretion, while 1,25(OH)2D3 is an important regulator of PTH and calcitonin gene transcription. We believe this to be the first demonstration of an effect of 1,25(OH)2D3 on the C cells thereby establishing a new target organ and site of action of vitamin D. Calcitonin is trophic to 1,25(OH)2D3 synthesis, which in turn inhibits calcitonin synthesis, which are the components of a new endocrinological feedback loop.
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PMID:Regulation of calcitonin gene transcription by vitamin D metabolites in vivo in the rat. 289 28

To study the effect of mucosal inflammation on tissue concentrations of somatostatin, the distribution and concentration of somatostatin in specimens of normal and abnormal (ulcerative colitis and Crohn's disease) ileum and colon were determined by a specific radioimmunoassay. Each tissue specimen obtained at surgery was separated by microdissection into the mucosa-submucosa and the muscularis externa. Immunoreactive somatostatin was acid-extracted from each layer before measurement. Gel chromatography was used to characterize immunoreactive somatostatin measured by radioimmunoassay; somatostatin-28 was the major immunoreactive species measured in human intestine. In normal colon, concentrations of somatostatin were not related to patient age. Concentrations of immunoreactive somatostatin in the mucosa-submucosa of the descending colon were significantly decreased in ulcerative colitis and in Crohn's colitis, compared with normal colon. There was no apparent relationship between concentrations of somatostatin and the duration of inflammatory bowel disease. However, somatostatin concentrations appeared to be lower in patients with severe colitis than in patients with minimal colitis. The decrease in mucosal-submucosal concentrations of somatostatin is in agreement with previous morphologic studies, which have suggested diminished populations of endocrine cells in ulcerative colitis. The possible role of somatostatin in the colon suggests that further studies of the alteration of this gut peptide may be useful in understanding a component of the pathophysiology of idiopathic inflammatory bowel disease.
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PMID:Somatostatin in the idiopathic inflammatory bowel diseases. 289 35

Timed urine collections were obtained from normal men and women for a study of somatostatin in urine. Somatostatin-14-like immunoreactivity (S-14 LI) was extracted from urine by adsorption to C-18 silica cartridges, and the extracts were analyzed by RIA directly or after gel and high pressure liquid chromatography (HPLC). S-14 LI was consistently detected in all urine samples. The mean S-14 LI content in 24-h collections in men [10.96 +/- 0.91 (+/- SE) pmol/24 h; n = 10; total volume, 1.96 +/- 0.09 L] was not significantly different from that in women (9.09 +/- 0.85 pmol/24 h; n = 10; total volume, 1.87 +/- 0.09 L). Gel chromatography of 24-h urine collections revealed three major peaks of S-14 LI coeluting with S-14, S-28, and a 12,000 mol wt species corresponding to prosomatostatin. HPLC analysis confirmed the presence of S-14, S-28, and the 12,000 mol wt form and additionally revealed a major fourth peak of 3,000 mol wt, closely related to S-28. Immunoreactivity corresponding to [Des,Ala1]S-14 (S-13) was identified by HPLC coelution with synthetic S-13 and reactivity in a centrally, but not N-terminally directed, S-14 RIA. The relative proportions of the different HPLC peaks varied considerably during the 24-h period. S-14 and S-28 were excreted preferentially during the day, whereas the 12,000 and 3,000 mol wt forms were excreted preferentially at night. The ingestion of a mixed meal evoked parallel increases in plasma S-14 LI and urinary S-14 LI excretion in six normal subjects. We conclude that the principal circulating forms of S-14 LI (S-14, S-28, S-13, and pro-S) are present in urine and that the measurement of urinary S-14 LI could provide a reliable index of integrated plasma S-14 LI concentrations.
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PMID:Measurement and characterization of somatostatin-14-like immunoreactivity in human urine. 289 3

Following development and validation of a radioimmunoassay for somatostatin, the immunoreactivity of this peptide in the plasma of ruminants was measured and the levels in sheep were 9-31 pM (mean 18 +/- 7 pM, n = 48), in lambs 10-54 pM (mean 25 +/- 10 pM, n = 18) and in calves 5-35 pM (mean 12 +/- 6 pM, n = 22). Somatostatin-like immunoreactivity was present in sheep in high concentrations in the antrum (2342 +/- 280 pmol/g wet weight), duodenum (446 +/- 73 pmol/g) and pancreas (832 +/- 208 pmol/g). Lower concentrations (6-150 pmol/g) were found in other regions of the gastrointestinal tract. Molecular sieve chromatography on Bio-Gel P-10 showed that while most of the somatostatin in the antrum was somatostatin-14, in the duodenum about 30% of the total immunoreactivity was somatostatin-28.
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PMID:Immunochemical characterisation of somatostatin in ruminants. 289 72

The actions of progressive doses of intraperitoneally (IP) administered somatostatin-14 (SS-14) and -28 (SS-28) on gastric secretion (acid, pepsin) and mucosal blood flow (MBF) were studied in conscious gastric fistula rats both under basal conditions and under additional administration of pentagastrin. Also, somatostatin-like immunoreactivity was measured in aortal blood in all groups as well as aortal gastrin levels under basal conditions. IP infusion of equimolar doses of SS-14 and SS-28 resulted in an equal and dose-dependent inhibition of basal as well as pentagastrin-stimulated gastric acid secretion. MBF was reduced by either peptide both in the basal and pentagastrin experiments. Under basal conditions pepsin secretion was significantly increased by infusion of SS-14 at the higher doses, by infusion of SS-28 only at the intermediate dose (3.1 nmole kg-1.hr-1). In the pentagastrin experiments, low and intermediate doses of SS-14 tended to lower pepsin outputs but the highest dose of SS-14 stimulated pepsin secretion, whereas SS-28 had no effect on pepsin. Administration of SS-28 inhibited gastrin only at the highest dose (12.3 nmole kg-1.hr-1), and SS-14 had no influence at all on gastrin. After IP infusion of both peptides, plasma SLI rose dose-dependently under basal and stimulated conditions. Gel chromatography indicated an in-vivo conversion of SS-28 to SS-14 or intermediate fragments. It is concluded that SS-14 and SS-28 delivered by IP infusion, inhibit basal and stimulated gastric acid equally in the rat without suppressing gastrin. The mechanism underlying SS-mediated pepsin stimulation is unknown.
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PMID:Gastric secretion and gastrin under progressive doses of somatostatin-14 and -28 administered intraperitoneally to the rat. 289 78


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