Prostaglandin E2 localization in the rat ileum.

The application of anti-prostaglandin E2 immunoglobulin to plastic-embedded thin sections of the rat ileum has permitted the localization of prostaglandin E2 in this tissue. In agreement with the published data (Chock & Schmauder-Chock (1988), Schmauder-Chock & Chock (1989)), the results also suggest the presence of an arachidonic acid cascade in the granules of various secretory cells of the gut. Since antibody labelling was found within the secretory granules of connective tissue mast cells, goblet cells, and Paneth cells, the presence of the arachidonic acid cascade in these granules is implied. The appearance of prostaglandin E2 over the non-cellular internal elastic lamina of arterioles suggests that it may have been secreted along with the elastin. The even distribution of prostaglandin throughout the cytoplasm of the erythrocyte is consistent with the concept that this cell scavenges the eicosanoid from the circulation. These data further link the secretory granule to the production of eicosanoids and therefore illustrate the potential sources of prostaglandins in the rat ileum.