Small doses of capsaicin given intragastrically inhibit gastric basal acidsecretion in healthy human subjects

Although the direct inhibitory effect of small dose of capsaicin on gastric secretory responses was proved in animal observations, the role of capsaic in-sensitive afferent nerves (CSAN) and the effect of capsaicin applied in small and high doses on gastric secretion in human has not been clarified y et. In this study we investigated the influence of different small doses (1 00-800 mu g) of capsaicin given intragastrically through an orogastric tube on gastric basal secretory responses in 10 healthy human subjects. Gastric basal secretory responses (volume, H+-concentration, H+-output) were measu red from the suctions of gastric juice for a 1-h period. It has been found that: a) capsaicin dose-dependently inhibited the volume and H+-output of g astric juice; b) ID50 was found to be about 400 mu g for capsaicin on gastr ic acid secretion; c) the time interval for capsaicin-induced gastric inhib ition existed for about 1 h indifferently from the higher dose (800 mu g) o f capsaicin given after. It has been concluded that the capsaicin (given in small doses) inhibits the gastric basal acid output via stimulation of the inhibition of capsaicin sensitive afferent nerves. (C) 1999 Elsevier Scien ce Ltd. Published by Editions scientifiques et medicales Elsevier SAS.