Abstract: "The experiments were undertaken to investigate the effects of microinjection of arginine vasopressin (AVP) and arginine vasopressin monoclonal antibody (AVPMcAb) into the medial amygdaloid nucleus (meA) on endotoxin-induced fever in rabbits. The results were as follows：①Injection of AVP into meA markedly suppressed en-dotoxin-induced fever. Injection of AVPMcAb into meA markedly augmented and prolonged fever responses. (2) Injection of AVP or AVPMcAb alone into lateral amygdaloid nucleus did not influence febrile responses. These results provided evidences that AVP might act within the meA to evoke antipyresis. "