Interrelationships between the gastric cytoprotective effects of vitamin A and beta-carotene and the gastric mucosal superoxide dismutase activity in rats.

Abstract

Gastric mucosal damage was produced in rats by the intragastric administration of 96% ethanol or 0.6 M HCl, according to the method of Robert et al. Vitamin A or beta-carotene, in doses of 10 mg/kg, given intragastrically 30 min before the administration of the necrotizing agents. The animals were killed 1 hr after the administration of the necrotizing agents. The following experimental parameters were studied, without and with application of vitamin A and beta-carotene; number of gastric lesions (ulcers); severity of gastric mucosal lesions (ulcers); gastric mucosal superoxide dismutase (SOD) activity. It was found that; vitamin A and beta-carotene, in doses of 10 mg/kg, are able to prevent significantly both the number and severity of gastric mucosal lesions (ulcers) produced by the application of 96% ethanol or 0.6 M HCl; the significant increase of ethanol-induced gastric mucosal SOD activity can be inhibited by the application of vitamin A and beta-carotene; vitamin A and beta-carotene are capable of preventing the development of gastric mucosal lesions (ulcers) produced by the intragastric administration of 0.6 M HCl, while these agents fail to compensate for the HCl-induced decrease of gastric mucosal SOD activity. It has been suggested that; vitamin A and beta-carotene are gastric cytoprotective agents; the ulcer preventive effects of vitamin A and beta-carotene are partly dependent on their scavanger behaviour.