Effects of Vagotomy on Histamine Content and Responses to Tetragastrin in the Rat Stomach

Vagotomy in the rat initially caused a significant reduction in acid secretion of the stomach after operation, with complete recovery noted 4 weeks later. Histamine content in the gastric wall also revealed a similar reduction and recovery after vagotomy. The increase in acid secretion responding to tetragastrin was observed as well to diminish markedly and then recover, over a similar course of time. Although tetragastrin caused a marked reduction of histamine content in the unoperated rat stomach, it caused no significant reduction of histamine content in the vagotomized stomach even in later periods after operation. The recovered gastric acid secretion in the vagotomized stomach might thus not be mediated by histamine. It is therefore suggested that the histamine release by tetragastrin needs the vagal nerve, and a receptor other than H_2-receptor may mediate the action of tetragastrin in the vagotomized stomach