Glycogen synthetase activity in liver: regulation by the autonomic nerves.

Electrical stimulation of the vagus nerve in intact or pancreatectomized rabbits resulted in a marked increase, within 5 minutes of the onset of stimulation, in the total activity of liver glycogen synthetase. The effect was completely counteracted by simultaneous stimulation of the splanchnic nerve, although stimulation of the splanchnic nerve alone had little effect on the enzyme. Injection of insulin caused an increase in both the total activity of glycogen synthetase and the activity that was independent of glucose-6-phosphate. The response of the enzyme to vagal stimulation was much faster than to administration of insulin.