The effect of acidifying the duodenal contents on splanchnic blood flow

Acidifying the duodenal contents with 0.1 N hydrochloric acid in the dog increased both hepatic artery and portal vein flow, and reduced mesenteric vascular resistance as well as hepatic artery and portal venous inflow resistances. The reaction is absent after intraduodenal injection of 30% glucose and physiological saline solutions. More concentrated acid leads to a greater increase in blood flow. The receptors of the circulatory reflex are situated in the duodenal mucosa and can be blocked with lidocaine.