Brain vasopressin is involved in stress-induced suppression of immune function in the rat

Abstract

The possibility that vasopressin (VP) is involved in stress-induced suppression of immune function was examined in rats. Intermittent electrical footshock for 60 min suppressed the proliferative response of splenic T cells to the mitogen concanavalin A as well as natural killer (NK) cytotoxicity, and the former change was partially, and the latter was completely, blocked by intracerebroventricular (i.c.v.) preadministration of a V1 receptor antagonist. The footshock-induced suppression of the T cell proliferative response was completely abolished by coadministration of a corticotropin-releasing hormone (CRH) receptor antagonist and the V1 receptor antagonist. The i.c.v. administration of VP suppressed the proliferative response of splenic T cells and NK cytotoxicity in an adrenal-independent manner. These effects were completely reversed by i.c.v. preadministration of the V1 receptor antagonist. These results suggest that brain VP, in conjunction with CRH, suppresses immune function through the V1 receptor in rats under stress.