Autonomic Mediation of the Effect of Raised Arterial Glucose upon Free Fatty Acids

Abstract
The intravenous infusion of 600 milligrams of glucose over 30 minutes caused a 17 percent fall in the concentration of free fatty acids in arterial blood of subjects who had fasted overnight. This response to glucose was abolished in subjects treated previously with ganglionic or adrenergic blocking agents. Small amounts of insulin were secreted in response to these glucose infusions, but in insulin-dependent diabetics incapable of altering plasma insulin to any great extent, the effect of glucose upon free fatty acids could be obtained provided the subjects were primed with long-acting insulin before the infusions were begun. The response of free fatty acids to doses of glucose which elevated the concentration of glucose in arterial blood by only 3 mg percent and the blockade of this response by autonomic and adrenergic blocking agents suggest that centers in the central nervous system exist which are capable of responding to elevations of arterial glucose by inhibiting the sympathetic tone partially responsible for sustaining lipolysis in fasting.