A study of gastric secretion induced by close arterial infusions of histamine in the dog

The effects of close arterial infusions of progressively increasing quantities of histamine into different regions of a denervated total stomach pouch were compared with the effects of infusions of histamine into the splenic vein in dogs under chloralose–urethane anesthesia. Infusions of 0.5 mg/h and 2.0 mg/h of histamine into the left gastric artery (lesser curvature of the stomach) were more effective than were the infusions of the same solutions into the gastrosplenic artery (greater curvature) as shown by the shorter latency to the appearance of free HCl and by a greater volume of secretion and total acid output per square centimeter of mucosa. Infusions of excessive quantities of histamine (32.0 mg/h) resulted in a reversible inhibition of HCl output as observed on the lesser curvature. The peptic activity of the gastric juice was low and decreased progressively with increasing amounts of infused histamine. Systemic blood histamine concentrations did not change during infusions of 0.5 mg/h or 2.0 mg/h of histamine into the gastric arteries or splenic vein; infusions of larger amounts of histamine (8.0 mg/h and 32.0 mg/h) resulted in a penetration of histamine into the general circulation and in systemic effects. These effects appeared earlier and with smaller quantities of histamine when the latter was infused into the portal vein close to the liver than when administered into the splenic vein as judged by the appearance of free hydrochloric acid in the gastric contents.