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)

Ultrastructural investigation of 274 human pituitary adenomas and 39 nontumorous adenohypophyses revealed two distinct types of secretion. Exocytosis was characteristic of prolactin cell adenomas, mixed growth hormone-prolactin cell adenomas, acidophil stem cell adenomas, and nontumorous prolactin cells. The second type, termed "transmembrane effusion," was noted in corticotroph, thyrotroph, gonadotroph, undifferentiated cell adenomas, and oncocytomas, as well as nontumorous corticotrophs, thyrotrophs, and gonadotrophs. It differed from that of prolactin cells and resembled diacrine secretion of gastrointestinal gastrin cells and membrane release in the neurohypophysis. In adenomatous and nontumorous growth hormone cells, neither exocytosis nor transmembrane effusion were apparent, hence a third type of release is suggested. Electron microscopic study of release mechanisms is helpful in the differential diagnosis of pituitary adenomas, since discharge of secretory products is not identical in the various tumor types.
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PMID:Fine structural features of secretion in adenomas of human pituitary gland. 677 93

A fraction increasing water and sodium absorption in rat duodenum was detected in the material obtained at an early stage of purification of the hitherto isolated duodenal hormones. In Wistar rats, duodenal loops were made in situ and filled with a solution containing 0.138 mM NaCl, with 14C PEG and 22Na as markers; the final content was collected after 1 h and the movements of water and Na measured. In contrast to secretin, cholecystokinin, and somatostatin, which induced duodenal secretion, and with pentagastrin, which induced duodenal absorption and stimulated acid secretion, this fraction induced duodenal absorption f Na and water without stimulating acid secretion. The fraction was obtained by chromatography of a concentrate of intestinal peptides in 0.2 M acetic acid on Sephadex G25 (fine), and its active component was found to be methanol-soluble at pH4 and insoluble at pH7.5. It was eluted from carboxymethylcellulose 22 with 0.04 M ammonium bicarbonate and gel filtration of Sephadex G50 *fine), resulting in a tenfold increase in activity. Incubation with chymotrypsin suppressed the biological activity, indicating a peptidic nature. The substance displayed biological and radioimmunological properties distinct from those of the gastrointestinal hormones. Particularly, no cross-reactivity was found with gastrin, prolactin, and angiotensin, which are known to increase intestinal absorption. It therefore seems possible that the activity described is due to a peptide that has as yet not been isolated. The name 'sorbin' is proposed for this active principle.
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PMID:Sorbin, a peptide contained in porcine upper small intestine which induces the absorption of water and sodium in the rat duodenum. 679 42

Synthetic gastrin releasing peptide (GRP) injected intraventricularly (1 microgram/rat), but not intravenously, suppressed rat prolactin (PRL) release induced by a Met-enkephalin analog, FK33-824 (10 micrograms/100 g body wt., iv). GRP also blunted PRL release induced by a dopamine antagonist, domperidone (1 microgram/100 g body wt., iv). In contrast, GRP did not suppress elevated plasma PRL levels sustained by a large dose of domperidone (10 micrograms/100 g body wt., iv). GRP (10(-5) M) had no effect on PRL release from superfused pituitary cells in vitro. These results suggest that GRP inhibits PRL secretion in the rat by acting through the brain to stimulate the dopaminergic mechanism.
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PMID:Inhibition of prolactin secretion by gastrin releasing peptide (GRP) in the rat. 682 49

The effect of porcine gastrin releasing peptide (GRP), a heptacosapeptide with potent gastrin releasing activity which has recently been isolated from porcine non-antral gastric tissue, on pituitary function was investigated in the rat. Graded doses of synthetic porcine GRP were injected intravenously and the animals were killed at various intervals after injection. Prolactin, growth hormone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) were measured in serum by specific radioimmunoassays. GRP had no significant effect on prolactin, growth hormone or FSH serum concentrations at any dose or sampling time studied. In contrast, the heptacosapeptide significantly stimulated LH release and suppressed TSH secretion with injection of low doses. There are striking structural and some functional similarities between GRP and bombesin, an amphibian skin tetradecapeptide which shows amino acid homology with the C-terminal region of GRP. This suggests that the endocrine effects of GRP may be mediated by its bombesin-like residue.
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PMID:Gastrin releasing peptide: endocrine functions in the rat. 685 57

Two possibilities of an inhibition of gastric acid secretion are compared in regard to effectiveness and side effects. Combined i.v. bolus injection of 0.3 mg/kg cimetidine caused almost complete inhibition of peptone-stimulated acid secretion in normal volunteers and duodenal ulcer patients-radomized and double blind investigated-to the same extent as high dose secretin (3 CU/kg/h i.v. infusion) in normal volunteers. Postprandial gastrin was unchanged by combined drug application, but was suppressed by secretin. Temporary blurred vision, dry mouth, and signifiant increase of serum prolactin were side effects of the drug combination, whereas secretin caused dose-dependent diarrhoea, increaded diuresis and elecvation of serum lipase, trypsin, and sodium. Inhibition of acid secretion by combination of the antimuscarinic drug pirenzepine with the H2-receptor blocking substances cimetidine was almost complete, i.e. more effective than the combination of classic anticholinergics with H2-blockers tested so far. Inhibition of acid secretion by secretin was dose-dependent; the dosage clinically applied so far (10 CU/kg s.c. and 0.5 CU/kg/h i.v.) had the smallest effect. In spite of first favourable results with secretin in bleeding mucosal lesions, the observed side effects cast doubt on its broad clinical applicability. A controlled clinical trial of the combination of cimetidine plus pirenzepine as prophylaxis of bleeding from mucosal lesions in risk patients seems to be indicated.
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PMID:[Effectiveness of cimetidine, pirenzepine and synthetic secretin on stimulated gastric acid secretion]. 689 78

Combinations of H2-receptor antagonists and classical anticholinergics inhibit stimulated gastric acid secretion more than either drug alone. In double blind, placebo controlled, randomised studies we have compared the effects of single and combined intravenous bolus injections of cimetidine and pirenzepine on peptone-stimulated acid secretion and serum gastrin in man. Combined injection of 3.0 mg/kg cimetidine and 0.3 mg/kg pirenzepine suppressed stimulated acid secretion significantly more than either drug alone, and by 90% in healthy volunteers (n = 8) and patients with duodenal ulcer (n = 5). Side-effects (prolactin stimulation, blurred vision) were diminished by reducing the combined dosages to 1.5 mg/kg cimetidine, to 0.075 and 0.15 mg/kg pirenzepine in another series (n = 10). Postprandial gastrin was not affected by any combination. Combination of cimetidine and pirenzepine suppress food-stimulated gastric secretion more effectively than combination of H2-blockers with classical anticholinergics. Pirenzepine--unlike classical anticholinergics--may distinguish between different subclasses of muscarinic receptors and have a more selective antimuscarinic action. Its interaction with H2-receptor antagonists on parietal cell function seems to be synergistic. Such a combination could be of advantage in patients with gastrinoma, in patients with ulcers and hypersecretion resistant to single drug treatment, and in critically ill patients as prophylaxis of stress ulcer bleeding.
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PMID:Interactions of cimetidine and pirenzepine on peptone-stimulated gastric acid secretion in man. 694 73

Endocrine abnormalities are common symptoms in patients with chronic renal failure. They are characterized by: 1. excessive somatotropin and prolactin secretion, 2. increased peripheral conversion of T4 to rT3, 3. secondary hyperparathyroidism accompanied by a relative insufficiency of calcitonin secretion, 4. hypogonadism, 5. hyperinsulinism and 6. decreased erythropoetin and 1,25-dihydroxy-vitamin D synthesis. In patients with chronic renal insufficiency normal function of the renin-angiotensin-aldosterone system, and pituitary-adrenal axis and normal PgA and PgE2 secretion are found. Increased blood levels of some peptide hormones (e.g. glukagon, gastrin) in patients with chronic renal failure seem to be caused, at least partially by secretion of biologically inactive prohormones and their decreased renal clearance.
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PMID:[Endocrine changes in chronic renal failure]. 700 96

The effects of different doses of D-sulpiride (1, 6, 12 and 25 mg, i.v.) on arterial blood pressure (ABP), heart rate (HR) and prolactin (PRL), growth hormone (GH), insulin and gastrin secretions have been studied in 8 normal men. D-Sulpiride increased systolic ABP with a maximum effect rather 12 mg i.v., while it had only slight effects on diastolic ABP and HR. PRL secretion was increased by D-sulpiride in a dose-dependent way, while insulin secretion was lowered and GH secretion slightly enhanced only in a restricted range of doses (6 mg and 12 mg i.v., respectively). Gastrin secretion seemed to be unaffected by D-sulpiride at any of the tested doses. These results are discussed in view of a possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in contrast with the relatively pure antagonistic action of the levo isomer.
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PMID:Possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in man. 703 36

We determined appropriate temperatures for sample storage and the resulting stability of 14 analytes commonly radioimmunoassayed in the clinical laboratory. Serum specimens to be tested for concentrations of cholylglycine, cortisol, digoxin, ferritin, follitropin, immunoglobulin E, lutropin, prolactin, thyroxin (also blood-spot thyroxin), triiodothyronine, and triiodothyronine uptake could be stored for up to two weeks at room temperature, refrigerated, or frozen without any loss of analyte activity. Specimens for insulin testing require freezing or refrigeration, and specimens for gastrin testing should be stored at -70 degrees C for optimal results.
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PMID:Effect of duration and temperature of storage on serum analyte stability: examination of 14 selected radioimmunoassay procedures. 703 99

The purpose of this study was to ascertain whether selected components of the uremic milieu adversely affected glomerular filtration rate (GFR), the glomerular protein filtration barrier, or the integrity of the proximal renal tubular brush border membrane. To achieve these goals, GFR and the excretion rates of albumin and of brush border derived-renal tubular epithelial antigens (RTE) were measured in normal rats and in rats with experimental nephropathies before and after the intravenous infusion of concentrated urine. This experimental protocol uniformly produced severe biochemical manifestations of uremia (for example 10-50-fold increases in BUN and creatinine, hyperphosphatemia, hyperkalemia, metabolic acidosis). However, despite these perturbations, GFR, albuminuria, and RTE excretion remained constant. To assess the influence of uremic hormonal derangements on renal function, GFR, albuminuria, and RTE excretion were measured in normal rats before and after inducing acute serum elevations of seven hormones whose concentrations are known to be increased in uremia (parathyroid hormone, growth hormone, insulin, glucagon, gastrin, prolactin, gastric inhibitory peptide). Again, GFR, albuminuria, and RTE excretion were not adversely affected. These results suggest that glomerular capillary function and proximal tubular brush border membranes are acutely resistant to many of the solute and hormonal derangements which are characteristic of uremia.
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PMID:A search for nephrotoxic factors within the uremic milieu. 715 30


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