Effect of Capsaicin on Gastric Acid Secretion and Mucosal Blood Flow in the Rat

Abstract

The effect of capsaicin, a pungent ingredient in capsicum fruit, upon gastric acid secretion and mucosal blood flow was assessed in the anesthetized rat. At each 15 minute interval, 0.3 ml saline solution, with or without various doses of pure synthetic capsaicin (the doses varied from 50 to 2,000 microgram/kg rat) was delivered into the gastric lumen via a gastric fistula. The gastric contents were withdrawn after 15 minutes for acid assay and replaced with a new saline solution. Capsaicin of increasing doses (up to 1,000 microgram/kg) progressively increased the acid output. Gastric inhibitors hexamethonium and atropine, completely abolished the acid secretion induced by capsaicin whereas secretin only partially reduced such a response. The systemic blood pressure was not affected by the capsaicin or the method employed. However, the aminopyrine clearance which was the indicator of the gastric mucosal blood flow increased in accordance with the increase in the acid output. It is suggested that the effect of capsaicin on the acid secretion and mucosal blood flow is by the release of endogenous gastric secretagogues which increase both tissue perfusion and the secretory activity.

Gastric motility changes in capsaicin-induced cytoprotection in the rat stomach.

“…On the other hand, activation of capsaicinsensitive afferent neurons enhances blood flow in a variety of somatic tissues (14). In fact, intragastric capsaicin produced a marked and sustained increase of mucosal blood flow, in agreement with the findings by others that capsaicin is able to enhance the gastric clearance of aminopyrine and aniline (20,21). Since this response was attenuated by indomethacin and desensitization of afferent neurons, similar to the motility response, the same mechanism might operate in these two responses induced by capsaicin.…”

Capsaicin-Induced Calcitonin Gene-Related Peptide Release from Isolated Rat Stomach Measured with a New Chemiluminescent Enzyme Immunoassay

“…Recent studies suggested that capsaicin-sensitive afferent neurons are involved in the pathophysiological regulation of gastric functions such as secretion and mucosal blood flow (GMBF) (10) and contribute to the mucosal protective mechanism against noxious stimuli (11)(12)(13)(14). The mammalian stomach is densely innervated by capsaicin-sensitive primary afferent neurons containing CGRP (15).…”

Effect of Eugenol on Gastric Function in Rats.

“…Earlier studies in capsaicin-treated rats showed maximum secretion of free acid to occur at a capsaicin dose of 1,000 ,u g/kg [6]; and with alcohol the maximal effect was seen at 40% [10]. By comparison eugenol appears to be a more potent secretagogue, as even a small dose of 10 ,u g/kg body weight resulted in a measurable response (Figs.…”

“…These contents were analyzed for free acids by titration with 0.01 N Na®H to pH 2.0 with thymol blue used as indicator. Free acids were expressed as mEq/liter of gastric contents; and secretory rate was given as ,u Eq/g of stomach [6].…”