Prostaglandin-induced pepsinogen secretion from dispersed gastric glands from guinea pig stomach

Abstract

We examined the actions of several prostaglandins (PG) on pepsinogen secretion from dispersed gastric glands prepared from guinea pig stomach. Pepsinogen secretion was stimulated by PGA1, PGA2, PGB2, PGE1, and PGE2. PGE1 and PGE2 were 10 times more potent than PGA1 and PGA2. Reducing the incubation temperature from 37 degrees to 4 degrees C or adding carbonyl cyanide m-chlorophenylhydrazone reduced PG-stimulated pepsinogen secretion. PGE2-induced pepsinogen secretion was not altered by atropine or dibutyryl cGMP. Potentiation of pepsinogen secretion occurred with PGE2 plus carbachol or the calcium ionophore A23187 but not with PGE2 plus secretin or 8-bromo-cAMP. Isobutylmethylxanthine increased the potency and the efficacy of the action of PGE2 on pepsinogen secretion. These results indicate that PGE1, PGA2, PGB2, PGE1, and PGE2 can modulate pepsinogen secretion from dispersed gastric glands from guinea pig stomach. Moreover, potentiation of pepsinogen secretion occurs when PGE2 is combined with secretagogues whose actions appear to be mediated by changes in cellular calcium (carbachol and A23187) but not with secretagogues whose actions appear to be mediated by changes in cellular cAMP (secretin and 8-bromo-cAMP). These data suggest that PG-induced pepsinogen secretion may be mediated by changes in cellular cAMP.