SUPPRESSIVE EFFECT OF VASOPRESSIN ON THE HYPERGLYCEMIC RESPONSE TO INTRACRANIAL INJECTION OF 2-DEOXY-D-GLUCOSE

Vasopressin (VP) is a peptide consisting of 9 amino acids which acts a s a neurotransmitter or neuromodulator in the central nervous system. Neurons containing VP project to some nuclei in the hypothalamus that have a role in energy metabolism. To clarify the possible role of VP o n glucose metabolism in the brain, we examined the effect of intracran ial injection of VP on the hyperglycemia induced by 2-deoxy-D-glucose (2DG) and obtained the following results. The hyperglycemic and hyperg lucagonemic responses induced by 2DG were significantly suppressed and enhanced by co-injections of VP and a VP-antagonist with 2DG, respect ively. However, co-injections of either VP or a VP-antagonist with 2DG had no effect on the change in plasma insulin concentration. These fi ndings suggest that central VP plays a suppressive role in the hypergl ycemic and hyperglucagonemic responses to 2DG.