Abstract
In many mammalian species (including humans) the parietal cell secretes both acid and intrinsic factor (IF). The aim of this study was to examine the direct effect of prostaglandin E analogues on basal and stimulated IF release in isolated, enriched rabbit parietal cells. The effects of graded concentrations (10−12 to 10−6 M) of 16,16-dimethyl prostaglandin E2 (DMPGE2) and 16-methyl,16-hydroxyl prostaglandin E, (misoprostol) on submaximal histamine-stimulated (10−6 M) secretion were tested. Both analogues failed to alter basal release of IF or aminopyrine accumulation (indirect measure of acid secretion). Increasing concentrations of DMPGE2 resulted in a dose-dependent inhibition of IF release (22 ± 8% decrease at 10−9 M; p < 0.05) and a maximal effective response at 10−7 M (54 ± 9%; p < 0.005). Dose-dependent inhibition of IF secretion was also observed with increasing concentrations of misoprostol, with a 22 ± 7% decrease at 10−9 M (p < 0.05) and maximal effective inhibition at 10−6 M (47 ± 8%; p < 0.01). Misoprostol and DMPGE2 inhibition of acid secretion paralleled IF release. Prostaglandin analogues appear to block IF release potently in histamine-stimulated parietal cells.