Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Somatostatin has been shown to inhibit the release of various polypeptide hormones including insulin, glucagon, gastrin, thyroid stimulating hormone, and growth hormone. The mechanism by which somatostatin inhibits the release of these various polypeptide hormones has not been fully elucidated. It has been reported that somatostatin increases the level of the second messenger cyclic GMP in rat brain and in the anterior pituitary gland. The present investigation was designed to determine if these responses seen in the anterior pituitary gland and brain were due to activation of guanylate cyclase [GTP-pyrophosphate lyase (cyclizing), E.C.4.6.1.2.], the enzyme that catalyzes the formation of cyclic GMP. Somatostatin at a concentration of 2 pM enhanced guanylate cyclase activity two-fold in rat cerebrum and anterior pituitary gland. This enhancement of guanylate cyclase activity was also seen in rat liver, pancreas, stomach, and small intestine at the same concentration of somatostatin. Increasing the concentration of somatostatin to 20 microM, caused a marked inhibition of guanylate cyclase activity in all these tissues. Dose-reponse curves done on gastric guanylate cyclase activity revealed that over a concentration range of 2 pM to 0.2 microM, somatostatin had a stimulatory effect on guanylate cyclase activity while at concentrations above 10 microM somatostatin was inhibitory to guanylate cyclase activity. The biphasic pattern of enhancement of guanylate cyclase activity at lower concentrations of somatostatin and inhibition at higher concentrations may help to explain some of the discrepancies seen with previous investigations with somatostatin, hormone release, and cyclic nucleotide metabolism.
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PMID:The interrelationship of somatostatin and guanylate cyclase activity. 611 Jan 70

1. The biochemical specificity and duration of action of a single 5 mg subcutaneous dose of des-AA1,2,4,5,12,13-D-Trp8-somatostatin were evaluated in eight patients with symptomatic pancreatic endocrine tumours. 2. There was a reduction by more than 50% for at least 10 h in plasma concentrations of growth hormone, glucagon, gastrin and motilin and for 4--5 h in plasma insulin, pancreatic polypeptide, gastric inhibitory polypeptide and enteroglucagon. 3. This study shows that this octapeptide analogue of somatostatin, like somatostatin itself, lacks specificity in the hormones it suppresses. However, its prolonged duration of action against several hormones when given subcutaneously suggests that it may be of therapeutic use in a number of disease states where excessive plasma concentrations of one or more of these hormones occur.
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PMID:Effect of a long-acting octapeptide analogue of somatostatin on growth hormone and pancreatic and gastrointestinal hormones in man. 611 53

The effect of hypophysectomy and bovine growth hormone (GH) administration on somatostatin (SRIF) content as well as gastrin content in the rat stomach was investigated. SRIF content was determined by a specific radioimmunoassay. The total SRIF content in the stomach had decreased 4 weeks after hypophysectomy but was restored significantly in those rats which were subjected to bovine GH administration for 7 days after hypophysectomy. Furthermore, in control rats, an increase in SRIF content in the stomach was observed after 7 days of GH administration. Similar changes in total content of gastrin were observed after hypophysectomy and bovine GH administration, although these changes were not significant. These results indicate that GH may influence gastric function through changes in SRIF and gastrin content in the stomach.
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PMID:Effect of hypophysectomy and growth hormone administration on somatostatin and gastrin content in the stomach of rats. 611 64

The hypoglycaemia of infantile hyperinsulinism is often exceedingly difficult to control. The use of somatostatin has been advocated recently in such infants because of its effect on inhibiting insulin release, but nothing is known of the wider effects of this potent hormone in the young child. Two infants presenting at 9 weeks and 5 days of age with severe hyperinsulinaemic hypoglycaemia were studied during an infusion of somatostatin. In both infants normoglycaemia was restored with suppression of insulin secretion. An increase in blood ketone bodies occurred, but no change was seen in blood pyruvate, lactate or alanine concentrations. The plasma concentrations of glucagon, cortisol, growth hormone, motilin, pancreatic polypeptide, gastric inhibitory of polypeptide, neurotensin, gastrin and vasoactive intestinal peptide decreased markedly during the somatostatin infusion. No consistent change occurred in plasma enteroglucagon or secretin values. We conclude that somatostatin effectively suppresses abnormal insulin secretion in infants, but it has profound effects on the release of nine other hormones. Further studies are needed to define the consequences of suppressing the release of these hormones before somatostatin can be used routinely in the management of infantile hyperinsulinism.
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PMID:Effect of somatostatin infusion on intermediary metabolism and entero-insular hormone release in infants with hyperinsulinaemic hypoglycaemia. 611 71

In dogs gastric secretion induced by tetragastrin and pancreatic secretion induced by secretin and/or cholecystokinin were inhibited by somatostatin at doses of 0.06-1 microgram X kg-1 X h-1 and 0.06-1 microgram X kg-1 X 0.5 h-1, respectively. Inhibition was a linear function of the logarithm of dose. Basal and 2-deoxy-D-glucose-induced gastric acid secretion was also significantly inhibited by low doses of somatostatin. Results in this study differ from those reported previously by clarifying the action of somatostatin as follows. 1) The inhibitory effect of somatostatin on pancreatic protein secretion was significantly greater than that on water and bicarbonate production. Somatostatin was more effective on cholecystokinin- than secretin-induced pancreatic secretion. 2) Although gastric mucosal blood flow (MBF) was affected by somatostatin, the reduction of MBF was not the primary mechanism responsible for its inhibitory action. 3) The low doses of somatostatin used in this study significantly inhibited gastric and pancreatic secretion without affecting the basal plasma concentrations of insulin, glucagon, growth hormone, gastrin, or secretin in the dogs, suggesting that the inhibitory action was not mediated by changes or reduction in plasma concentration of these hormones.
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PMID:Action of somatostatin on stomach, pancreas, gastric mucosal blood flow, and hormones. 612 5

A series of 25 apudomas of the gastrointestinal tract (22 cases), bronchus (2 cases), and thymus (1 case) were subjected to staining with silver impregnation (Masson-Fontana and Grimelius) techniques and with the commercial immunoperoxidase kits for the peptide hormones adrenocorticotropin, calcitonin, gastrin, glucagon, growth hormone, human chorionic gonadotropin (hCG), insulin, somatostatin, and vasoactive intestinal peptide. Of the tumors studied, 16 were regarded as malignant, and 5 of the patients showed clinical symptoms due to inappropriate hormone secretion. A total of 16 tumors contained cells positive for 1 or more (6 were multihormonal) of the hormones studied. One bronchial carcinoid stained for hCG, which has not been previously reported. In addition, one of the rectal carcinoids contained somatostatin-positive cells, only once described previously. The thymic tumor proved frankly malignant, most probably identical to the oat-cell carcinoma recently described. The findings also substantiate the recent suggestion that gastrointestinal carcinoids cannot be adequately classified on the basis of silver stains only and strongly advocate the use of the immunoperoxidase kits in routine assessments of all the endocrinologically active tumors, whatever their localization might be.
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PMID:Stainability of the peptide hormones in gastrointestinal apudomas as demonstrated by immunoperoxidase kits. 614 78

The effect of somatostatin on splanchnic haemodynamics in patients with liver cirrhosis is not clearly defined, as some Authors reported a decrease in portal pressure and in liver blood flow during i.v. administration of this hormone, while others did not. In 19 subjects with liver cirrhosis and portal hypertension the following parameters were measured before and during i.v. infusion of somatostatin (7.5 micrograms/min): porto-hepatic gradient, effective hepatic plasma flow, specific splenic blood flow, cardiac output. Moreover the gastrin-G-17 plasma levels, those of insulin and growth hormone were measured. Effective hepatic plasma flow decreased significantly during somatostatin infusion (P less than 0.05), averaging a 15% decrease. Porto-hepatic gradient, specific splenic blood flow, cardiac output did not vary significantly. Gastrin, insulin and growth hormone plasma levels decreased significantly (P less than 0.02, 0.01, 0.05). These data indicate that somatostatin infused at the dose of 7.5 micrograms/min provokes endocrine effects, but as far as the splanchnic circulation is concerned, it induces a slight decrease in liver blood flow without affecting portal hypertension.
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PMID:[Effect of somatostatin on splanchnic hemodynamics in liver cirrhosis]. 615 Nov 51

A highly sensitive immunoenzymatic technic is presented. The method involves three sequential steps: (1) primary antibody, (2) biotin-labeled secondary antibody, and (3) avidin-biotin-peroxidase complex. Avidin, an egg white protein, has four binding sites for the low-molecular-weight vitamin biotin. Many moieties of biotin can be coupled to the peroxidase molecule. Thus, since a relatively large amount of avidin is incubated with biotin-labeled peroxidase, avidin serves as a link between biotin-peroxidase molecules; in turn, biotin-peroxidase serves as a link between avidin molecules. Consequently, this large lattice-like complex with biotin-binding capability can be attracted to the sites of biotin-labeled antibody, producing a superior staining sensitivity. Several commercially available radioimmunoassay antibodies (e.g., antiglucagon, prolactin, gastrin, growth hormone, and thyroid-stimulating hormone antibodies) were tested for immunohistochemical staining. The unlabeled antibody peroxidase-antiperoxidase method fails to stain gastrin or thyroid-stimulating secretory cells when using these antibodies, and a relatively high antibody concentration is required to produce a positive reaction for glucagon, prolactin, and growth hormone. In contrast, the avidin-biotin-peroxidase complex method successfully demonstrates polypeptide hormones even when antibodies are diluted 20 to 40 times.
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PMID:A comparative study of the peroxidase-antiperoxidase method and an avidin-biotin complex method for studying polypeptide hormones with radioimmunoassay antibodies. 616 37

The tetradecapeptide bombesin was originally isolated from frog skin. Bombesin-like peptides have since been detected in mammalian gastrointestinal tract, brain and lung. These peptides have potent pharmacological effects on the central nervous system; they cause contraction of intestinal, uterine and urinary tract smooth muscle; and stimulate the release of other peptides including gastrin, cholecystokinin, motilin, pancreatic polypeptide, neurotensin, insulin, enteroglucagon, prolactin and growth hormone. Specific plasma membrane receptors for bombesin have been demonstrated on pancreatic acinar cells, brain membranes and pituitary cells. Studies defining the physiological importance of bombesin have been impeded by the lack of a bombesin receptor antagonist. Here we describe experiments which demonstrate that a peptide originally described as a substance P receptor antagonist, [D-Arg, D-Pro, D-Trp, Leu ]substance P, is also a bombesin receptor antagonist. This peptide competitively inhibits the ability of bombesin to stimulate enzyme secretion from dispersed pancreatic acini, and also inhibits the action of other peptides that interact with the bombesin receptor.
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PMID:A synthetic peptide that is a bombesin receptor antagonist. 620 45

Prospective screening was carried out in 12 members of three families with multiple endocrine adenopathies, type I (MEA,I) and in 14 patients with no multiple endocrine adenopathies with and without other endorcinopathies. Elevated basal and responsive (after a meal) plasma concentrations of a relatively new candidate-hormone, human pancreatic polypeptide (hPP), were associated with pancreatic apudoma tumors in three asymptomatic patients with multiple endocrine adenopathies, type I. Two of these patients had excision of the tumors that resulted in normal plasma hPP concentrations postoperatively. Both tumors contained hPP predominantly by immunocytochemistry; one, a pure pancreatic polypeptide apudoma, was studied extensively demonstrating also by radioimmunoassay a high content of hPP and negligible amounts of insulin, glucagon, somatostatin, vasoactive intestinal polypeptide and gastrin. In this patient plasma concentrations of other polypeptides including insulin, glucagon, somatostatin, vasoactive intestinal polypeptide, gastrin, parathyrin, thyrocalcitonin, prolactin, corticotropin, growth hormone, thyrtropin and amine, serotonin, were within normal limits. The other patient, after excision of an hPP-detected pancreatic mixed hPP-gastrinoma, also became eugastrinemic postoperatively. Normal basal plasma hPP concentrations, but with exaggerated hPP responses to a meal in 11 patients, were associated with various combinations of islet cell hyperplasia, antral G cell hyperplasia with moderate hypergastrinemia and parathyroid hyperplasia. The patients with multiple endocrine adenopathies who have demonstrated this type of increased hPP response to a meal have not been operated on but are at risk for islet hyperplasia. Four of the 12 patients with multiple endocrine adenopathies, type I, with both normal basal and normally responsive hPP concentrations have no evidence as yet of pancreatic involvement.
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PMID:Pancreatic polypeptide as screening marker for pancreatic polypeptide apudomas in multiple endocrinopathies. 624 7


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