Core temperature of tailless rats exposed to centrifugation.

Although it comprises only about 5% of the total body surface area of the rat, the tail can dissipate about 17% of the animal's body heat. In the present study, we have investigated the role of the tail in the altered thermoregulation of rats during acute hypergravic exposures (achieved by centrifugation). Such exposures produce a rapid fall in core temperature (Tc) leading to a sustained hypothermia. In addition to the Tc changes, there is a significant, but transient increase of tail temperature, indicative of an accelerated rate of heat loss. To determine the extent to which increased heat loss from the tail affects the hypothermic response, rectal temperature changes were measured in both tailless and intact rats subjected to centrifugation. Results from this study indicate that the increased heat loss from the tail per se does not contribute in a measurable way to the hypothermia induced by centrifugation stress.