Effect of 16-16-dimethyl-prostaglandin E2 on ulceration of isolated amphibian gastric mucosa.
In order to investigate the cytoprotective action of 16-16-dimethyl-prostaglandin E2 (16-16D), we studied its effect on sacs of isolated amphibian gastric mucosa known to ulcerate with high frequency in the absence of nutrient HCO3-. The actions of 16-16D, 2.85 X 10(-6) M, were also studied in an in vitro chamber. The incidence of ulceration in HCO3- -free nutrient media containing 10(-4) M histamine was significantly reduced by 16-16D. When artificial gastric juice (AGJ) was instilled into the lumen of the sac, protection occurred only after a pretreatment period of 60 min. Cytoprotection was not observed when active secretion of H+ was inhibited with 10(-3) M metiamide, and AGJ was placed in the lumen of the sac. In open sheets of fundus stimulated with 10(-4) M histamine, 16-16D did not influence H+ secretion. Isc was significantly higher than in control tissues. We conclude that 16-16D is cytoprotective in amphibian gastric mucosa by an action independent of changes in acid secretion or in blood flow. In addition, our studies suggest that 16-16D may increase the availability to the surface cells of nutrient HCO3- produced by actively secreting oxyntic cells.
D015064:16,16-Dimethylprostaglandin E2 / Q000627:therapeutic use*; D000136:Acid-Base Equilibrium / Q000187:drug effects; D000818:Animals; D001001:Anura; D002021:Buffers; D005753:Gastric Mucosa / Q000187:drug effects* / Q000503:physiopathology; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008785:Metiamide / Q000494:pharmacology; D011459:Prostaglandins E, Synthetic / Q000627:therapeutic use*; D011892:Rana catesbeiana; D013276:Stomach Ulcer / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors
D002021:Buffers; D011459:Prostaglandins E, Synthetic; D008785:Metiamide; D006632:Histamine; D015064:16,16-Dimethylprostaglandin E2