Effect of alpha and beta adrenoreceptor antagonists on glucagon-induced inhibition of gastric acid secretion in cats.

The aim of the present study was to examine the effect of alpha and beta adrenoceptor blockade on gastric acid secretion, mucosal blood flow (GMBF) and catecholamine content of the gastric mucosa during glucagon-induced inhibition of gastric acid secretion. The secretory response to continuous infusion of pentagastrin (6 micrograms/kg/h) was reduced by regitine (0.5 mg/kg/h) and propranolol (25 micrograms/kg/h). Glucagon (25 ng/kg/h) further slightly decreased HCl secretion. GMBF was also significantly inhibited by regitine and propranolol. Administration of glucagon continued decreasing of the GMBF. By determining the change in the ratio of blood flow to secretory rate, this reduction in mucosal blood flow was found to be secondary to a fall in secretion. In these studies a concomitant increase in noradrenaline content of the gastric mucosa was observed: after regitine by 50%, after propranolol--by 32.5%, after these blockers given simultaneously--by 75%. The level of noradrenaline was higher after subsequent administration of glucagon. Our results indicate that more than one component is responsible for the inhibitory effect of glucagon on pentagastrin-stimulated gastric acid secretion.

Effect of glucagon on pentagastrin-stimulated gastric acid secretion and mucosal blood flow in cats.

The effect of glucagon given intravenously on pentagastrin-stimulated gastric acid secretion and gastric mucosal blood flow was studied in anaesthetized cats with gastric fistula. In parallel the catecholamines content in the gastric mucosa was measured. A continuous infusion of glucagon (25 ng/kg/h) caused a significant decrease of acid output (on the average by 33%) and gastric mucosal blood flow (by 40%). In these studies a concomitant increase in noradrenaline content of gastric mucosa was always seen (on the average by 108%). By determining the change in the ratio of blood flow to secretory rate a reduction in mucosal blood flow was found to be primary to the fall in secretion. The studies indicate that the inhibitory effect of glucagon on pentagastrin-stimulated acid secretion is due to restriction of mucosal blood flow. The results confirm also earlier data that glucagon stimulates the release of catecholamines.

The composition of fatty acids of the serum and erythrocytes after an alimentary cholesterol load.

The content of certain fatty acids of the serum and erythrocytes was compared in rabbits before and after 11 days on a diet with added cholesterol. The alimentary cholesterol load reduced the levels of linolic and arachidonic acids in the serum, while in the erythrocytes the level of linolic acid was increased. Changes in the levels of the remaining determined fatty acids were not significant statistically.

Levels of linoleic acid and saturated and monounsaturated fatty acids in selected lipid fractions of the serum and platelets in patients with coronary arterial disease.

The levels of serum fatty acids in the serum and in the serum fractions of cholesterol esters (ECH) and triglycerides (TG) and the levels of these acids in these fractions of platelets were compared in healthy controls and in patients with clinically manifested coronary arterial disease. Decreased level of linoleic acid was found in the serum and in the ECH fraction of the serum in the patients, with a rise in the level of palmitic acid in the ECH fraction of the serum of these patients. The level of linoleic acid in the ECH and TG platelet fractions in these patients was not different from that in the healthy controls, while in the platelet TG fraction of the patients the level of palmitoleic acid was raised, and the level of oleic acid was increased in the platelet ECH fraction.

Effect of low body temperature on gastric secretory activity in the guinea pig under urethane general anaesthesia.

Effect of low body temperature on gastric secretory activity in the guinea pig under urethane general anaesthesia. Acta Physiol. Pol., 1978, 29 (1): 61-66. The effect of low body temperature on spontaneous and histamine (H) stimulated or Nalpha Nalpha-dimethylhistamine (NDMH)-stimulated gastric secretion was investigated in the guinea pig under general anaesthesia with urethane. In normothermia NDMH had a stronger stimulatory action on acid secretion In hypothermia (30 degrees C and 25 degrees C) only NDMH showed some stimulating effect. The obtained results point to the necessity of strict controlling of body temperature in the experiments performed on animals under general anaesthesia and suggest that the lack of effect at low temperature may be connected with an inhibition of the processes of H side-chain methylation when the rate of metabolic processes in the organism has fallen.

Influence of some inhibitors of histamine metabolism on the gastric secretion.

Influence of some inhibitors of histamine metabolism on the gastric secretion. Acta Physiol. Pol., 1977, 28 (6): 515-520. The influence of inhibitors of histamine metabolism on histamine (H) and Nalpha Nalpha-dimethylhistamine (NDMH) stimulated gastric secretion was studied in guinea-pigs and cats. Inhibitors of monoamine oxidase (MAO) and diamine oxidase (DAO): N-oxide diacetylaminopyridine (AAP) and N-oxide 2 aminopyridine (AP) increased HCI secretion in the gastric juice after H and NDMH. Inhibitors of N-methyl transferase: amodiaquine (A) and quinacrine (Q) increased HC1 secretion in the gastric juice after H but not after NDMH. The lack of action of A and Q on NDMH-stimulated gastric secretion suggests, that in guinea-pig and cat NDMH is not methylated additionally at the imidazole ring and therefore, it is a stronger gastric secretagogue than histamine itself.