VASOPRESSIN V1 RECEPTOR IN RAT HIPPOCAMPUS IS REGULATED BY ADRENOCORTICAL FUNCTIONS

Two subtypes of arginine vasopressin (AVP) receptors (V1 and V2) have been distinguished, In this study, we examined the characteristics of AVP binding in rat hippocampus and the effects of bilateral adrenalect omy and adrenal steroids on its [H-3]AVP binding. [H-3]AVP binding to rat liver and the hippocampal membranes was strongly inhibited by the V1 antagonist, OPC-21268. ADX resulted in a significant decrease in th e B-max of AVP binding in the hippocampus. Chronic treatment with aldo sterone and corticosterone restored the ADX-induced reduction, but tre atment with dexamethasone did not. These results suggest that the AVP V1 receptor in the hippocampus is regulated by adrenocortical neuroreg ulatory functions.