The chronic effects of nicotine monomethidide on gastric secretion in pylorus-ligated rats

Résumé L'action de la nicotine monométhyliodine (NMI) sur la sécrétion gastrique basique et sur les concentrations de choline de cervelles, d'acétylcholine et de nicotine et sur l'activité de la transacétylcholinestérase a été étudiée chez des rats. Le NMI, sel quaternaire de nicotine, qui ne traverse pas la barrière hématoencéphalique, a été administré dans de la gélatine à 6% en dosage sous-cutané de 1000 g/ml/kg/jour pendant 14 jours. Le NMI n'a pas changé de paramètres et aucune trace de nicotine n'a été découverte dans les homogénates de cervelles complètes.     

Inhibitory influence of ligation of the small intestine on gastric secretion in the pylorus-ligated rats

Résumé La ligature de l'intestin, particulièrement du duodénum, gêne la sécrétion gastrique chez le Rat à pylore lié avec ou sans fistule fine.     

Effect of subdiaphragmatic vagotomy on production of gastric ulcers in pylorus-ligated albino rats

Summary A reduction in volume and free and total acidity of gastric content was noted along with reduction in ulcer index, with a shift of the site of ulceration from fundus to the glandular part of stomach, following vagotomy in pylorus-ligated rats. Low volume and acidity explains the absence of ulcers in the fundus, but the increased involvement of glandular part in ulceration is possibly due to weakening of the mucosal barrier following vagotomy.     

Effect of subdiaphragmatic vagotomy on production of gastric ulcers in pylorus-ligated albino rats.

A reduction in volume and free and total acidity of gastric content was noted along with reduction in ulcer index, with a shift of the site of ulceration from fundus to the glandular part of the stomach, following vagotomy in pylorus-ligated rats. Low volume and acidity explains the absence of ulcers in the fundus, but the increased involvement of glandular part in ulceration is possibly due to weakening of the mucosal barrier following vagotomy.     

Urinary output of rats in response to subcutaneous injections of adrenaline

Zusammenfassung Es werden der Effekt einer s.c. Injektion von Adrenalin auf die renale Ausscheidung von Wasser und Elektrolyten bei Ratten sowie Versuche über die Korrelation verschiedener Dosis abhängiger, renaler Adrenalin-Wirkungen beschrieben.     

The effect of hog gastrin on gastric secretion in chronic gastric fistula rats

Résumé L'action de la gastrine de porc a été étudiée chez des rats mâles munis de fistules gastriques. La gastrine était injectée par voie s.c. à des doses de 1–2 ml: 1 ml équivalant à l'activité de 10 g de muqueuse de porc. Le volume de suc gastrique, le volume de suc gastrique par 100 g, l'acidité totale et le débit d'acide accusèrent une pointe dans la première h, alors que la concentration en acide atteignit son maximum vers la troisième h. Le débit de la pepsine diminua entre la troisième et la cinquième h et augmenta légèrement entre la cinquième et la sixième h.

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This research was supported in part by grants from the National Science Foundation (No. GB 6105) and from the AMA ERF, to J. H. T. — Dr.Robitscher of Ayerst Laboratories kindly supplied the ICI-50123.     

Chronic effects of nicotine on gastric secretion in vagotomized rats

Résumé La sécrétion gastrique a été mesurée dans des rats mâles avec ligature pylorique de deux heures, après 14 jours d'injections sous-cutanées de nicotine ou de NaCl. Les résultats de l'administration de nicotine furent une augmentation du volume du suc gastrique, de la production d'acide et de la production de pepsine. La vagotomie abdominale bilatérale a prévenu la stimulation gastrique secreteuse, provoquée par la nicotine.     

Effects of intraventricular administration of insulin on thyrotropin secretion in rats

Intraventricular administration of insulin stimulates increases in the levels of thyrotropin-releasing hormone and thyrotropin in rats.     

Effects of intraventricular administration of insulin on thyrotropin secretion in rats

Summary Intraventricular administration of insulin stimulates increases in the levels of thyrotropin-releasing hormone and thyrotropin in rats.Ovine insulin was kindly supplied from Shimizu Pharm. Co., Ltd. (Japan).Rat TSH radioimmunoassay kit was kindly supplied by NIAMDD.     

Stimulation of gastric secretion by prostaglandin F2 alpha in rats.

In rats with chronic gastric fistulas, prostaglandin F2 alpha stimulated the gastric acid secretion in graded doses of 50, 100, 200 and 400 microgram/kg b.wt, while higher doses above 1 mg/kg b.wt tended to inhibit significantly. The gastric antisecretory effect of prostaglandin E1 could not be altered or modified by subsequent treatment of prostaglandin F2 alpha, while the latter alone without any prior treatment of the former, stimulated output of gastric juice, HCl and pepsin without significantly affecting the concentration of these components.     

Kinetics of insulin secretion in response to glucose by isolated islands of Langerhans from the fetal rat]

Isolated islets of Langerhans from 21.5 day-old foetal Rats were studied in a perifusion system in vitro. The overall dynamics of insulin release by the foetal islets in response to glucose 13.9 mM is biphasic and qualitatively similar to that obtained with islets of adult Rats. The magnitude of the initial phase of insulin secretion is similar for the foetal and adult islets. The second phase is fourfold higher in the adult than in the foetus. The response of foetal islets occurs, 45 to 60 sec. after the increase of glucose concentration in the medium and a maximum insulin release for the first phase is obtained with a lag period of 2 min. The difference between foetal and adult islets is essentially quantitative.     

Tachykinins in regulation of gastric motility and secretion

The tachykinins constitute a family of neuropeptides with a common C-terminal amino acid sequence. The best known tachykinin is substance P. Tachykinins are found in the nerve plexuses and nerve fibers in the stomach of all species examined. The circular muscle layer is densely innervated, whereas the longitudinal layer and the mucosa are less intensively innervated. Tachykinins are also found in a significant number of afferent neurons with cell bodies in the dorsal root ganglia. Release of tachykinin can be demonstrated in response to both electrical stimulation of the vagus nerves and application of capsaicin. In the stomach all three known tachykinin receptors seem to be present. Although species variations exist, NK-2 receptors are generally present on the musculature, NK-1 receptors on both neurons and muscles, and NK-3 receptors on neurons only. Tachykinins stimulate motility in all parts of the stomach, but tachykinins also appear to inhibit motility in certain situations. Also, motility initiated centrally, mediated through the vagus nerves, is influenced by tachykinins. The precise role of tachykinin in the various motor programs in the stomach is not clear. Gastric acid secretion is influenced by tachykinins in several species. Tachykinins do not seem to act as neurotransmitters directly on parietal cells, but may have a modulatory function. The importance of tachykinins for the regulation of pepsinogen and hormone secretion from the stomach remains unclear. Received 24 August 1999; received after revision 1 December 1999; accepted 3 December 1999