Evidence That Histamine is a Gastric Secretory Hormone in the Rat

Abstract

One test on each of six chronic gastric fistula rats was made in which after a 12-hour fast C14 l-histidine was injected subcutaneously. Twenty-four hours later, while still fasting, aminoguanidine HCl (AG) (2 mg of the base), a powerful diamine oxidase inhibitor (an antihistaminase), was given hourly subcutaneously through an indwelling needle day and night for 3 additional days. Twenty-four hours after the start of AG, food was given for 12 hours; fasting then occurred for two 12-hour periods, and then food was given again for 12 hours. The average urinary C14 histamine counts per minute during the various AG periods were: first AG control period, 105; second AG control period, 104; 12-hour feeding period, 185; first 12-hour postfeeding-fasting period, 157; second postfeeding-fasting period, 68; final 12-hour feeding period, 106. It is concluded that, on feeding, C14 histamine was released in quantities adequate to stimulate gastric secretion when aminoguanidine was present to prevent histamine destruction.