Healing-promoting action of the zinc-cimetidine complex on acetic acid-induced gastric ulcers in rats.

We investigated the effect of the zinc-cimetidine complex on the healing of acetic acid-induced gastric ulcers in rats. When the effects of test drugs were assessed on the 15th day after acetic acid injection, the zinc-cimetidine complex at oral doses of 15.0 (11.4 mg as cimetidine), 30.0 and 60.0 mg/kg twice daily promoted the ulcer healing in a dose-dependent manner. Cimetidine was effective at oral doses of over 45.4 mg/kg twice daily. ZnCl2 was ineffective on all ulcer parameters. The effect of the combination of cimetidine and ZnCl2 was similar to that of cimetidine alone. The zinc-cimetidine complex had already inhibited the increase in thiobarbituric acid reactants in the ulcerated region before the ulcer-healing effect of this compound was recognized. A single oral administration of the complex at 15 and 30 mg/kg to normal rats was ineffective in inhibiting acid secretion and in increasing serum gastrin levels, although cimetidine was markedly effective on both parameters. These results indicate that the zinc-cimetidine complex at about 1/4 the dose of cimetidine was as effective as cimetidine when the ulcer-healing effects of both compounds were compared with the same dose of cimetidine. In addition, the ulcer-healing effect of this complex may be due, at least in part, to the inhibition of lipid peroxidation but not due to the inhibition of acid secretion or the trophic effect of gastrin.