Antisecretory and cytoprotective doses of enprostil do not alter gastric mucosal blood flow

Prostaglandins of the E series are antisecretory and cytoprotective. Cytoprotection occurs in the deep but not superficial gastric mucosa. It has been hypothesized that the mechanism of cytoprotection involves increased gastric mucosal blood flow (GMBF). However, basal and stimulated gastric mucosal blood flow is greater in the deep than superficial corpus mucosa. The purpose of this study was to investigate the effect of a prostaglandin E2 analog, enprostil, on GMBF in the deep mucosa, where cytoprotection is observed, in both antisecretory and cytoprotective doses. Gastric mucosal blood flow in the deep half of the mucosa was measured by the hydrogen gas clearance method before, during and after intragastric perfusion of enprostil, 0.1-100 micrograms/kg, in urethane anesthetized rats. Enprostil did not alter GMBF in any of the doses tested. Therefore, the cytoprotective action of enprostil is mediated by factors other than a primary increase in GMBF.