Central Nervous System Mediated Inhibition of Insulin Secretion Due to 2-Deoxyglucose

Abstract

Central nervous system control of insulin secretion in the unanesthetized rat was studied in relation to the injection of 2-deoxyglucose (2-DG) via a previously implanted cannula in the lateral cerebral ventricle. The hyperglycemic response to central 2-DG, at a dose (2 mg) which was without effect when injected systemically, was unaccompanied by a rise in insulin levels. The acute insulin response to intraperitoneally injected glucose was markedly attenuated by prior central administration, but not by systemic administration of 2-DG. Adrenalectomy inhibited the hyperglycemic response to central 2-DG and also removed the 2-DG induced inhibition of the insulin response to exogenous glucose. In contrast, central 2-DG was without effect on arginine-stimulated insulin secretion. The results indicate that the neurogenic control of insulin secretion in response to central glucopenia is mediated by the adrenals rather than by direct neural innervation of the beta cells. The differences in the insulin responses to glucose and arginine can be explained by the different effects of epinephrine on these insulin secretogogues. 1 Supported in part by USPHS Grant n. AM-14418 and a Buswell Fellowship by the State University of New York at Buffalo.