Pharmacological study of basal acid secretion by the rat isolated fundus preparation.

The rat isolated stomach preparation secretes acid in the absence of exogenous stimulants. This basal secretion of acid was unaffected by high concentration of antagonists to stimulated secretion in this preparation and by TTX. Basal secretion was inhibited by omeprazole (10(-7)-10(-5) M), KSCN (10(-4)-10(-2) M) and to a lesser extent by somatostatin (10(-6)-10(-5) M) but not by verapamil (3 X 10(-4) M), nifedipine (3 X 10(-4) M) and trifluoperazine (10(-3) M). Two long-acting H2-antagonists, oxmetidine and SKF 93479 (10(-5)-10(-4) M) inhibited basal secretion by a mechanism not involving an action at H2-receptors. It is concluded that basal secretion in this in vitro preparation is independent of the endogenous release of known stimulants of acid secretion and activity of the intrinsic nervous system.