A Study of the Factors Involved in the Production of Gastric Ulcers by the Restraint Technique

Abstract

Summary 1.Six species of experimental animals were tested for the production of gastric ulcers by restraining the animals in wire screen for 24 hours. Mice, rats, guinea pigs, and hamsters had an incidence of gastric ulceration of 92, 86, 46, and 4 per cent, respectively. Gastric ulcers were not induced in rabbits or monkeys by the restraint technique. 2.As the time period of the restraint of the rat was increased from 6 to 24 hours, the incidence of gastric ulcer increased. Recovery of the stomach to normal after 24 hours of restraint required 72 hours. 3.The incidence of gastric ulcers in rats that were deprived of food was found to be higher than that of fed rats, when both groups were restrained for the same time period. Food deprivation also prolonged the time required for the gastric mucosa to return to normal. 4.Younger rats (50 to 185 gm.) had a higher incidence of gastric ulcers than older rats (over 250 gm.) when both groups were subjected to short periods of restraint. Weight did not seem to be an important variable when the rats were restrained for a period of 24 hours. 5.Repeated periods of restraint, 18 hours a day, increased the incidence and severity of gastric ulcers. Rumen ulcers were produced by this procedure. 6.In rats, 8 days after operation, hypophysectomy and bilateral subdiaphragmatic vagotomy did not reduce significantly the incidence of animals with ulcers. Bilateral adrenalectomy significantly increased the incidence and severity of the ulcers produced by restraint. 7.The restraint technique provides a simple, rapid, nonsurgical means of producing ulcers in the glandular portion of the stomach.