Effect of 16,16-dimethyl prostaglandin E 2 on mucus glycoprotein biosynthesis in rat stomach and duodenal glands

Abstract

The present study describes the effect of 16,16-dimethyl prostaglandin E 2 (16,16-dmPGE 2) on mucus glycoprotein biosynthesis in rat stomach and duodenal glands. After in vivo treatment with 16,16-dmPGE 2 (10 μg/kg subcutaneously) for 1 h, the incorporation rate of [ 3H]galactose, [ 3H]glucosamine, and [ 3H]serine in the ex vivo vascularly perfused stomach was determined by light microscopic autoradiography. As was previously found by us for the surface mucous cells in the fundus of 16,16-dmPGE 2-treated rats, the incorporation of [ 3H]galactose and [ 3H]glucosamine (indicative of mucus glycoprotein synthesis) in the isthmus was increased two- to fourfold. Small if any increases were detected in the mucous cells near the base of the glands of the fundus (neck cells), the mucous cells in the antrum and the mucous cells in the duodenal glands. Total protein synthesis as measured by [ 3H]serine incorporation was not increased in any of these cells. We conclude that 16,16-dmPGE 2 has different effects on mucus glycoprotein biosynthesis in various regions of the rat stomach. Increased biosynthesis in the fundus points to a role for mucus in the prostaglandin-induced protection of the gastric mucosa against injury.