Regulation of hippocampal corticosterone receptors by a vasopressin analogue

Vasopressin can alter hippocampal corticosterone receptor number, as a congenital absence of a peptide in the Brattleboro rat results in decreased concentrations of the receptor; this deficit can be reversed with des-glycinimide arginine vasopressin (dGVP), a centrally-acting VP analogue. We examined whether vasopressin might regulate less dramatic fluctuations of hippocampal corticosterone receptor number in the normal rat. Administration of dGVP failed to alter the rate of or extent of down- or up-regulation of hippocampal corticosterone receptors by circulating corticosterone, suggesting that alteration of neural VP content is not a mediating step in such regulation.