Prostaglandins and sulfhydryls may mediate gastric protection induced by verapamil in rats.

Verapamil, a type-1 calcium-channel blocker, given intraperitoneally, macroscopically protected the gastric mucosa of rats from 96% ethanol-induced lesions in a dose-dependent fashion. This effect was significant when verapamil at 10 or 20 mg/kg was given 1 hr before ethanol. Histopathologically, verapamil prevented the development of deep necrotic lesions, but did not preserve the surface epithelium. Gastric acid secretion in both pylorus-ligated rats and gastric-diversion rats was inhibited by 20 mg/kg of verapamil. Gastric motility measured by a balloon method was dose-dependently inhibited by verapamil. Verapamil protection was significantly diminished by pretreatment with subcutaneous indomethacin (30 mg/kg) and iodoacetamide (100 mg/kg). The gastric motility inhibited by verapamil was not reversed by indomethacin and iodoacetamide. These results indicate the participation of both endogenous prostaglandins and sulfhydryls of the gastric mucosa in verapamil protection against ethanol damage, but do not relate to a suppression of gastric motility.