Effect of 16,16-dimethyl prostaglandin E2 on gastric surface epithelial cell damage induced by 20% ethanol in rats.
Prostaglandins protect against the gross damage of gastric mucosa induced by 50-100% ethanol, but do not protect surface epithelial cells (SEC) from necrosis. Since this induced damage to SEC is so severe, we attempted to determine the effects of a prostaglandin on slightly induced SEC damage and gastric potential difference (PD) in response to low concentrations of ethanol. The necrotizing effects of graded concentrations of ethanol (10-50%) to SEC on the rat gastric mucosa were studied by scanning electron and light microscopy. Intragastric instillation of 20% ethanol (v/v, 1 ml/100 g body wt.) to pylorus-ligated rats for 10 min induced slight and reproducible SEC damage consisting mainly of the apical cell membrane erosion of SEC. Pretreatment with 16,16-dimethyl prostaglandin E2 (dmPGE2, 3 or 30 micrograms/kg, p.o. or s.c.) afforded protection of the SEC from 20% ethanol-induced damage. However, the cytoprotective effects of dmPGE2 were abolished when gastric contents were emptied prior to 20% ethanol instillation. Intragastric instillation of ethanol immediately reduced PD in a concentration-related manner. dmPGE2 (3 or 30 micrograms/kg, s.c.) had no effect on the reduction of gastric PD after 20% ethanol treatment and the recovery of reduced PD to normal levels. We conclude that dmPGE2 has no cytoprotective effect on 20% ethanol-induced SEC damage in rat gastric mucosa.
Ohno
T
T
Department of Applied Pharmacology, Kyoto Pharmaceutical University, Japan.
Nakagawa
M
M
Nishimura
S
S
Takeuchi
K
K
Okabe
S
S
D015064:16,16-Dimethylprostaglandin E2 / Q000494:pharmacology*; D000818:Animals; D004847:Epithelial Cells; D000431:Ethanol / Q000494:pharmacology*; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D011459:Prostaglandins E, Synthetic; D000431:Ethanol; D015064:16,16-Dimethylprostaglandin E2