The gastric antisecretory actions of prostaglandin E2 and stable prostacyclin analogues against different secretagogues in perfused whole-stomachs of rat or mouse in vitro.

1 The characteristics of the antisecretory actions of prostaglandin E2 (PGE2) and two stable prostacyclin analogues during different rates of acid stimulation have been evaluated in the lumen-perfused isolated whole stomach of the rat and mouse. 2 In the rat isolated stomach, histamine induced a dose-dependent increase in acid output. Preincubation with PGE2 caused a dose-related and surmountable inhibition. 3 The stable prostacyclin analogues, 6 beta-PGI1 and a 16-phenoxy derivative likewise caused a surmountable inhibition of histamine-stimulated acid output from rat stomach. 4 PGE2 had inconsistent actions on the acid secretion stimulated by pentagastrin, methacholine or dibutyryl cyclic adenosine 3',5'-monophosphate. 5 In the mouse isolated stomach, acid secretion was stimulated by low concentrations of histamine, pentagastrin or methacholine. 6 PGE2 failed to inhibit histamine-stimulated acid output from mouse stomach, but high concentrations of the potent 15-phenoxy analogue did show anti-secretory activity. 7 The results indicate the usefulness of the rat isolated stomach for studying the interaction of prostaglandins with the acid secretory process in mammalian gastric mucosa.