Role of Endogenous Arginine Vasopressin in Physostigmine Induced Hypothermic Response in Rats / 医学研究杂志

ABSTRACT

Objective To study the subcutaneous injection of physostigmine (PHY) inducing hypothermic response and its relationship with endogenous arginine vasopressin ( AVP). Methods Core temperature and motor activity were monitored by telemetry in female rats maintained at an ambient temperature of 25℃. Tail skin temperature was measured at 30 min intervals with digital thermometer. The central cholinergic antagonist, scopolamine ( lmg/kg ) and AVP V_1 receptor antagonist were administered during the period of PHY (0. 25mg/kg) induced hypothermia. Plasma AVP concentration was measured at 50 min after administration of PHY. Results Subcutaneous injection of PHY led to a rapid reduction in core temperature concomitant with a marked elevation in the heat loss from the tail. The hypothermic response of PHY was blocked by scopolamine and AVP V1 antagonist. Plasma AVP concentration increased markedly at 50 min after PHY. Conclusion The results suggest that endogenous A VP could be involved in PHY -induced hypothermic processes. This may be a novel mechanisms of action for a reversible anticholinesterase drug ( such as PHY ) - induced hypothermia.