Effect of vasoactive drugs on gastric blood flow measured by a cross thermocouple method in rats.
To make a continuous recording of gastric blood flow (GBF) in rats, application of a cross thermocouple method was investigated together with related pharmacological studies. When secretagogues (tetragastrin, histamine and methacholine) were given intravenously in a dose sufficient to stimulate acid secretion, the increases in GBF observed were much the same as those seen when the aminopyrine clearance technique was used. When epinephrine and norepinephrine were administered via a close intraarterial route in the stomach, there was an initial decrease followed by an increase in the GBF. This biphasic response was antagonized by phentolamine, but not by propranolol, thereby suggesting that those agonists predominantly stimulate alpha-adrenoceptors. On the contrary, isoprenaline produced an increase in GBF which was attenuated by propranolol. Acetylcholine produced an increase in GBF, which was blocked by atropine. Histamine increased the GBF, and such was inhibited by diphenhydramine, but not by cimetidine, suggesting a stimulation of H-1 receptors by histamine. Serotonin, in a lower dose, and tetragastrin also elicited an increase in GBF. However, with a higher dose of serotonin, there was an increase followed by an apparent decrease in GBF. From these results, it was concluded that the cross thermocouple method is practical for a continuous recording the rat GBF in response to vasoactive drugs.
D000109:Acetylcholine / Q000494:pharmacology; D000632:Aminopyrine / Q000378:metabolism; D000818:Animals; D006632:Histamine / Q000494:pharmacology; D008297:Male; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D013270:Stomach / Q000098:blood supply* / Q000187:drug effects; D013566:Sympathomimetics / Q000494:pharmacology; D013758:Tetragastrin / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects*
D013566:Sympathomimetics; D000632:Aminopyrine; D013758:Tetragastrin; D012701:Serotonin; D006632:Histamine; D000109:Acetylcholine