AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 3 255-G262, Copyright © 1980 by American Physiological Society
Role of fatty acid oxidation in mechanism of action of gastric secretagogues
J. Chacin, G. Martinez and E. Severin
The role of beta-oxidation in the mechanism of stimulation of acid
secretion was examined in toad gastric mucosa in vitro. The incubation with
4-pentenoate selectively inhibited in a dose-dependent manner the rate of
14CO2 formation from [1-14C]octanoate. Pretreatment with 20 mM 4-pentenoate
sharply reduced the respiratory and secretory responses to theophylline and
histamine. Tracer studies showed a major utilization of exogenous octanoate
over glucose and pyruvate by the in vitro toad gastric mucosa. Theophylline
and histamine stimulated by 69% the rate of octanoate oxidation. Over 60%
of the increments in oxygen uptake produced by theophylline and histamine
accounted for the increments in octanoate oxidation, whereas glucose and
pyruvate together accounted for less than 25%. Octanoate-dependent
respiration was shown to correlate with octanoate oxidation under both
inhibition with 4-pentenoate and stimulation with theophylline.
Theophylline stimulated by 25% the rate of octanoate oxidation in Cl--free
glucuronate-nutrient solutions. The present work provides further evidence
for the primary role of fatty acid oxidation in the mechanism of acid
secretion in amphibian.
