The cytoprotective effect of prostaglandin E2 on taurocholate-induced erosions in gastric mucosa of the rat. Light microscopic, morphometric and scanning electron microscopic investigations.

The morphological changes associated with the cytoprotective effect of prostaglandin E2 (PGE2) following sodium-taurocholate (NaTC) erosive injury in the gastric mucosa were investigated in male rats. A single topic application of NaTC (80 mMol) induced multiple gastric erosions in all animals. Application of 200 micrograms PGE2/kg body weight prior to NaTC treatment led to a significant 90% decrease in the lesion-score in PGE2-protected animals. Light microscopic morphometric studies of the mucus-producing cells in the fundus mucosa were carried out. Within the PGE2-protected animals a significant increase was observed in the length of zones of the mucus-producing cells at the surface and in the foveolae (both PAS-positive and alcian-blue-positive cells). Compared to the NaTC-injured animals, this increase amounted to 8.1% for the PAS-positive, and 6.1% for the alcian-blue-positive zone. Compared to the untreated controls, these values were 4.7% and 3.2% respectively. In the scanning electron microscope we observed a characteristic explosive release of mucus and damage of the cell's surface membranes in the NaTC-treated animals. The PGE2-protected rats showed a predominance of exocytosis of mucus vesicles which formed a characteristic mucus network at the surface membrane. Our investigations suggest that the cytoprotective effect of PGE2 may, in part, be due to an increase in mucus production and to a modification of mucus adherence at the cell membrane.