Non-Invasive Method of Inducing Hypothermia in Multiple Rats Simultaneously

摘要

Hypothermia has been and continues to be a problem faced by military personnel when operating in cold environments or when water immersion in moderate temperatures results in the loss of body heat that is not compensated for by heat production. Vascular leakage of large protein molecules and accompanying water or extravasation manifested in a loss of vascular volume is one of the pathophysiological findings resulting from rewarming following hypothermia. Recent work in this laboratory with hyperthermic rats has shown that hyperthermia-induced extravasation can be quantitated and the organ sites located using recovery of Evans Blue from tissues. Recovery of fluorescent microspheres from the same rats indicated a change in reticuloendothelial system function with hyperthermia. Prior to using the same techniques to quantitate these changes following hypothermia and rewarming, it was necessary to develop a non-invasive method of inducing closely controlled hypothermia in rats. This report describes the construction of three water cooled copper coils into which anesthetized rats were placed. Valves in the parallel tubing connecting these coils allowed the cooling and subsequent rewarming of three rats simultaneously with only one circulating water bath. Data on 3 sets of 3 rats are presented.