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

The antisecretory effects of H2-receptor antagonists are limited by food ingestion. The contributions of the cephalic-vagal and gastrinergic mechanisms to this interaction were examined in two 14-hour randomized, cross-over studies in 24 healthy volunteers. In the first study, either ranitidine or placebo was administered IV by a pH-feedback-controlled infusion pump during fasting, modified sham feeding, or food ingestion. Sham feeding resulted in a well-defined and abrupt interaction with the antisecretory effect of ranitidine (lasting 2-3 hours), after which fasting pH levels were regained. The second study, with the same design, showed that gastrin release occurred during this cephalic-vagal phase but was not attenuated by the additional infusion of the anticholinergic pirenzepine. Following eating, intragastric acidity increased and remained elevated for more than 6 hours. This increase was accompanied by prolonged hypergastrinemia, which was not diminished by pirenzepine. Pirenzepine did, however, enhance the antisecretory effect of ranitidine after both sham feeding and food ingestion. The interaction of food or sham feeding with the antisecretory effect of H2 antagonists is a consistent phenomenon. In both the cephalic-vagal and the gastric phases of secretion, this interaction appears to be partially mediated by a noncholinergic release of gastrin.
 ...
PMID:The cephalic and gastric phases of gastric secretion during H2-antagonist treatment. 186 Jun 25

In conscious dogs with esophageal, gastric and pancreatic fistulae, sham-feeding and meat feeding increased the pancreatic protein secretion to a peak, reaching about 39% and 69% of CCK8 maximum, and raised plasma pancreatic polypeptide (PP) levels. Pirenzepine given intravenously (i.v.) (30 nmol.kg-1 or 3 mumol.kg-1) reduced dose-dependently the pancreatic protein and plasma PP responses to sham-feeding and meat feeding, being about 100 times less potent as an inhibitor than atropine. Neither pirenzepine nor atropine affected near-maximal pancreatic bicarbonate and protein responses to secretin (164 pmol.kg-1.h-1) and CCK8 (170 pmol.kg-1.h-1), but both antimuscarinic agents significantly inhibited pancreatic responses to lower doses of these secretagogues. When added to the incubation medium of dispersed canine pancreatic acini, pirenzepine reduced dose-dependently the amylase responses only to urecholine, and not to CCK or gastrin, being about 1000 times less potent as an inhibitor than atropine. This report provides an evidence that pirenzepine inhibits pancreatic secretion in a similar manner to atropine, but that pirenzepine, in both in vivo and in vitro studies, is 2-3 orders of magnitude less potent as an inhibitor than atropine, indicating that the muscarinic pathway of the exocrine pancreas has a low affinity for pirenzepine and may thus involve M2-receptors.
 ...
PMID:Subtypes of muscarinic receptors in canine pancreatic secretion in vivo and in vitro. 244 73

Pirenzepine, a newly described antagonist of selective muscarinic receptors (M1), has been shown to be a potent inhibitor of acid secretion. To determine whether this property of pirenzepine can be explained in part by its actions on hormones regulating acid secretion, we examined pirenzepine's effects on gastrin and somatostatinlike immunoreactivity (SLI) secretion from the isolated, perfused rat stomach. Carbachol at a dose of 10(-6) M inhibited SLI and stimulated gastrin secretion. Both atropine and pirenzepine reversed these effects in a dose-dependent fashion with D50 values of 1 X 10(-9) and 1 X 10(-7) M, respectively, against gastrin stimulation and 1 X 10(-8) and 1 X 10(-7) M, respectively, against SLI inhibition. Pirenzepine caused a progressive parallel rightward shift in the dose-response curves for SLI inhibition and gastrin stimulation by carbachol, suggesting competitive inhibition. The apparent inhibitory constant (ki) was calculated to be approximately 2 X 10(-9) M. These results indicate that gastrin and SLI release from the stomach is governed by high-affinity muscarinic receptors that are sensitive to pirenzepine. Pirenzepine's action as an acid secretory inhibitor, and possibly as an ulcer therapy drug, may be explained in part by these effects on gastric hormone regulation.
 ...
PMID:Pirenzepine-sensitive muscarinic receptors regulate gastric somatostatin and gastrin. 285 28

The effects of the antimuscarinic drugs pirenzepine and atropine on somatostatin and gastrin portal levels under basal conditions and during bethanechol infusion have been investigated in anesthetized dogs. Iv bolus administration of pirenzepine (1 mg/kg) or atropine (0.1 mg/kg), decreased gastrin concentrations, but did not affect basal somatostatin levels. During 120 min of bethanechol infusion (160 micrograms/kg/h) gastrin levels increased but somatostatin levels were unchanged. Pirenzepine (1 mg/kg iv bolus), administered at the 60th min of bethanechol infusion, decreased the gastrin concentrations, and markedly enhanced somatostatin levels. Under the same conditions atropine (0.1 mg/kg iv bolus) decreased gastrin levels, but had little or no effect on somatostatin levels. These results indicate that muscarinic receptors with similar affinity for pirenzepine and atropine mediate excitatory cholinergic influences on gastrin release. By contrast, muscarinic receptors with higher affinity for pirenzepine seem to be involved in the cholinergic inhibition of somatostatin release: by selectively blocking these receptors, pirenzepine may increase portal somatostatin levels.
 ...
PMID:The effects of the antimuscarinic drugs pirenzepine and atropine on plasma portal levels of somatostatin and gastrin in the dog. 289 79

Effects of orally-administered pirenzepine and propantheline bromide on food-stimulated gastric acid secretion, serum gastrin concentration, salivary flow and heart rate were compared in 10 duodenal ulcer patients in a placebo-controlled, double-blind study. Pirenzepine inhibited acid secretion by 25, 36 and 44% at doses of 50, 100, and 150 mg, respectively, while propantheline inhibited acid secretion by 32 and 41% at doses of 15 and 45 mg, respectively. None of the doses of pirenzepine affected food-stimulated serum gastrin concentrations, whereas 45 mg propantheline increased serum gastrin concentration significantly above placebo control. Enhancement of gastrin release by propantheline was not due to its antisecretory effect since intragastric pH after the meal was held constant at 5.0 by intragastric titration in vivo. Pirenzepine had no significant effect on heart rate and little or no inhibitory effect on salivary volume, depending on the dose administered. By contrast, both doses of propantheline increased heart rate and reduced salivary volume significantly (P less than 0.05). Thus, pirenzepine and propantheline in the doses administered inhibited acid secretion to approximately the same extent but pirenzepine had fewer effects on other organs.
 ...
PMID:Comparison of two antimuscarinic drugs, pirenzepine and propantheline, on gastric acid secretion, serum gastrin concentration, salivary flow and heart rate in patients with duodenal ulcer disease. 297 73

We have studied the effects of the selective muscarinic M1-receptor antagonist pirenzepine and the non-selective muscarinic antagonist atropine on bombesin- and peptone-stimulated gastrin release in healthy subjects. Pirenzepine (i. v. bolus 0.6 mg/kg) and atropine (i. v. bolus 15 micrograms/kg, followed by an infusion of 5 micrograms.kg-1.h-1) were given in doses equipotent in terms of reduction of gastric acid secretion. Neither affected bombesin- or peptone-stimulated gastrin release. These findings do not support the involvement of M1-receptors in the cholinergic regulation of gastrin release and suggest that the reduction in acid secretion caused by pirenzepine is not mediated by inhibition of gastrin release.
 ...
PMID:The effect of selective and non-selective cholinergic blockade on bombesin- and peptone-stimulated gastrin release. 369 21

Pirenzepine is an antimuscarinic drug highly selective for M1 receptors, which proved to be effective in the treatment of peptic ulcer. Aim fo the present study was to assess the frequency of relapses over a 12-month period subsequent to the anatomic healing of duodenal ulcer, obtained with pirenzepine (PRZ). Sixty patients (44 M, 16 F, mean age 42,9 years range 19-73) entered the study. They were allocated at random to a double-blind treatment with placebo or PRZ given at two different dosages, 50 or 100 mg/day respectively, over a consecutive period of 12 months. Clinical evaluations were foreseen every 3 months, while endoscopy and hematology, gastrin plasma levels and intra-ocular pressure assessment at the end of the 6th and 12th month. The intake of antacids or equivalent drugs, in addition to the baseline treatment, was not allowed. Statistical evaluation of the results was performed by chi-square test with Yates' corrections. Difference in percentage of patients without relapses at 6th month and at 12th month was clearly in favour of PRZ compared with placebo. Non changes in the indices of gastrin plasma levels, liver or renal functions and intraocular pressure were reported. No patients complained of side-effects pirenzepine-related. The treatment with full dosage (100 mg/day) did not increase the rate of positive responsiveness compared to that of standard dosage (50 mg/day). It might confirm the importance of the role played by nocturnal acid secretion. For this reason, a decrease in relapses could be expected with the dosage of 100 mg if it was given in a single evening dose. However, therapy with PRZ turned out effective and did not produce side-effects. Its selectivity avoided clinical effects related to a cholinergic system block.
 ...
PMID:[Pharmacologic treatment of duodenal ulcer. Short and long-term results with pirenzepine in ambulatory patients]. 377 6

The effects of pirenzepine on the plasma concentrations of gut hormones in the fasting and postprandial states were studied in six healthy subjects. On separate days and in random order, 10 mg pirenzepine, in 2 ml of solvent, or 2 ml saline (0.15 mol/l) were given intravenously 30 min before a standard normal breakfast (2220 kJ). Pirenzepine was not found to affect basal or postprandial levels of insulin, glucagon, gastric inhibitory peptide (GIP), neurotensin, vasoactive intestinal peptide (VIP) or somatostatin. The basal concentration of pancreatic polypeptide (PP) was lowered (p less than 0.05) and the postprandial elevation reduced, though not significantly. While the basal concentration of motilin was also suppressed (p less than 0.05), the postprandial elevation remained unchanged following pirenzepine. The release of enteroglucagon was reduced significantly in the basal and postprandial states (p less than 0.05 and p less than 0.025 respectively). The postprandial gastrin response was prolonged slightly, but insignificantly, by pirenzepine. It is concluded that pirenzepine does not exert any major or unexpected actions on the hormonal control of digestion.
 ...
PMID:The effect of pirenzepine on meal-stimulated gastrointestinal hormones. 611 82

In a double-blind, placebo controlled and randomised secretory study the effectiveness of pirenzepine, ranitidine, and their combination was compared intraindividually in eight healthy subjects receiving intravenous bolus injections. Pirenzepine (0.15 mg/kg) plus ranitidine (0.6 mg/kg) suppressed peptone-stimulated gastric acid secretion from 69 +/- 11 to 2 +/- 0.4 mmol H+/3 h; the mean percentage inhibition was 97%. Postprandial gastrin was unaffected. There were only minor side-effects in a few experiments (reduction of salivation, brief blurring of vision), but no prolactin stimulation after ranitidine or ranitidine plus pirenzepine. The combined application of ranitidine and pirenzepine inhibited meal-stimulated acid secretion more effectively and produced fewer side-effects than the combination of cimetidine plus pirenzepine studied previously.
 ...
PMID:Complete inhibition of food-stimulated gastric acid secretion by combined application of pirenzepine and ranitidine. 611

To characterize and quantitate pathways of stimulation of gastric secretion via vagal excitation induced by 2-deoxy-D-glucose, we used graded doses of the two muscarinic antagonists, atropine and pirenzepine. Studies were performed in four conscious gastric fistula dogs with antral vagotomy to eliminate the gastrin release component of the vagal response. To further localize the site of action of the antagonists, both were tested against bethanechol, which stimulates secretion at postganglionic sites. Acid and pepsin secretion stimulated by either bethanechol or the vagus were inhibited in a dose-responsive manner by both atropine and pirenzepine, which displayed similar potencies. These data indicate that: 1) the vagus acts on the gastric fundus solely via muscarinic receptors; 2) the muscarinic receptors controlling gastric secretion are of the high-affinity (M-1) subtype; and 3) the vagus is very sensitive to atropine with D50 less than 1.4 nmol/kg. Heart rate was increased up to 120 beats/min above the resting rate by atropine; half-maximal increase was calculated to occur at 10 nmol/kg (ED50). Pirenzepine had a much less potent effect on the heart; the ED50 was 200 to 300 times greater than that for atropine. These data indicate that heart rate is affected by a mechanism acting via a muscarinic receptor pathway that has a low affinity for pirenzepine (M-2 receptor subtype).
 ...
PMID:Effects of pirenzepine and atropine on vagal and cholinergic gastric secretion and gastrin release and on heart rate in the dog. 613 90


1 2 3 Next >>