Effect of antacid treatment on endogenous prostaglandin synthesis in human antral and duodenal mucosa.

Using 14C-labeled arachidonic acid as precursor for in vitro prostaglandin synthesis, the effect of an antacid containing Al (OH)3, Mg(OH)2 and CaCO3 on endogenous prostaglandin synthesis was investigated in antral and duodenal mucosa of healthy volunteers. After three weeks of treatment with a high-dose antacid, there was no detectable change in the total capacity of the mucosa for prostaglandin synthesis, but the prostaglandin profile was markedly altered. The relative amounts of PGE2 and PGF2 alpha synthesized by antral and duodenal mucosa increased at the expense of the prostaglandins A2/B2, thromboxane A2, and prostacyclin. In a short-term study, this change was not observed following a single antacid dose within 1 hr after application. It is concluded that long-term antacid treatment may alter the prostaglandin pattern formed by gastroduodenal mucosa and this may be related to its therapeutic effect.

[Prostaglandin synthesis in stomach and duodenal mucosa of the human: effect of aspirin with and without antacid]. / Die Prostaglandinsynthese in Magen- und Duodenalmukosa des Menschen: Einfluss von Aspirin mit und ohne Antazidum.

A decreased PG E2 content in gastric mucosa of humans receiving a longterm antirheumatic therapy has been reported to be partially reversed after a one week treatment with an antacid (Reimann et al., Fortschr Med 102 [1984], 25-26). Therefore the effect of an Aspirin treatment of healthy volunteers with or without an antacid on the prostaglandin synthesis in gastric or duodenal mucosa was investigated. 14C-labelled arachidonic acid was used as substrate during in vitro incubation of the mucosal homogenate for determination of the endogenous formation of prostaglandins. Aspirin suppressed the total prostaglandin synthesis to less than 10% of control after one week treatment. The addition of a high dose antacid did not influence this inhibition, and no significant effect on the prostaglandin profile was detectable. It is concluded that antacids do not influence the suppression of the endogenous prostaglandin synthesis by NOSAC's, however another effect, eg a prolonged stability of PG E2 in a less acidic environment is more likely.