AJP - Regulatory, Integrative and Comparative Physiology, Vol 250, Issue 5 764-R769, Copyright © 1986 by American Physiological Society
Inhibition of gastric emptying and feeding by fenfluramine
P. H. Robinson, T. H. Moran and P. R. McHugh
To assess the mechanism by which the anorectic agent fenfluramine
influences feeding, we examined in Macaca mulatta the effect of
intragastric fenfluramine (2 mg/kg) on both feeding and the gastric
emptying of saline and glucose test meals. Gastric emptying was measured by
the dye-dilution technique, using chronic indwelling intragastric cannulas.
The emptying of normal saline was inhibited by fenfluramine as was the
initial bolus phase of the emptying of glucose. In contrast, the subsequent
controlled phase of glucose emptying was unaffected in two out of four
animals, slightly inhibited in one, and strongly inhibited in only one
monkey. Rhesus monkeys trained to drink a glucose solution to satiety
drank, on average, 21% less after fenfluramine. The emptying of the
consumed glucose solution from the stomach was reduced by 39%, whereas
gastric volume at satiety was reduced by only 10%. The reduction of intake
was strongly related to the degree of inhibition of gastric emptying. These
results support an important role for the inhibition of gastric emptying in
fenfluramine-induced suppression of feeding.
