Decreased release of somatostatin into the portal vein following electrical vagal stimulation in the cat

Abstract

Electrical vagal stimulations were performed in anesthetized cats, in which the spleen and the intestine below the duodenum had been removed. The cats were provided with acute antral pouches which were perfused during the experiments. Insulin, glucagon, gastrin and somatostatin were measured in portal vein blood (consisting of blood from the stomach and the pancreas). The antral perfusates were analyzed for gastrin and somatostatin. Electrical vagal stimulation increased the release of insulin and glucagon into the portal vein. Gastrin was elevated in antral perfusates and portal vein blood, whereas somatostatin increased in the antral perfusates, but was reduced in portal vein blood. Apparently antral somatostatin, like gastrin, is released into the blood. The finding that portal vein somatostatin was decreased following vagal stimulation, indicates that the release of somatostatin from another large source of somatostatin, presumably the fundic region of the stomach or the pancreas, was decreased by vagal activation.