AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 2 244-G247, Copyright © 1986 by American Physiological Society
Histamine H2-receptor involvement in the regulation of gastric emptying
A. Dubois and D. O. Castell
The effect of cimetidine on gastric emptying and gastric secretion was
evaluated in eight chair-adapted rhesus monkeys. A dye-dilution technique
was used to simultaneously determine gastric emptying, gastric secretion of
water and hydrogen ion (H+), and intragastric volume and H+ concentration.
A continuous intravenous infusion of either saline (control) or cimetidine
(4 mg X kg-1 X h-1) was administered during a 40-min fasting steady state
and following intragastric instillation of 100 ml of water. During fasting,
administration of cimetidine abolished H+ secretion and significantly
decreased fractional emptying rate and water secretion (P less than 0.05).
After the water load, cimetidine also suppressed H+ secretion and reduced
fractional emptying and water secretion compared with control (P less than
0.05). Increasing HCl concentration of the test solution to 50 mM
significantly decreased fractional emptying both during saline and further
suppressed emptying during cimetidine infusion (P less than 0.05). In
conclusion, cimetidine significantly decreased gastric emptying during
fasting and following a liquid load. Restoring intragastric acidity to
physiological levels removed the effect of gastric acid suppression on
emptying and unmasked the full potential for cimetidine to decrease gastric
emptying, possibily through an effect on gastric smooth muscle.
