Studies on the nervous regulatory mechanism of blood sugar levels.

Intraarterial injection into the carotid artery or intravenous injection of glucose caused a decrease in efferent discharge rate of the adrenal nerve and an increase in discharge rate of the pancreatic branch of the vagus nerve. Decrease in blood sugar level following administration of insulin increased adrenal nerve activity and caused a decrease in the activity of the pancreatic branch of the vagus nerve. Administration of 2-DG resulted in an increase in adrenal nerve activity and a decrease in pancreatic nerve activity. Glucose also caused a decrease in discharge rate of afferent nerve fibers from glucoreceptors in the liver. The results suggest the existence of a nervous regulatory mechanism of blood sugar levels.