Emotional hyperthermia in spontaneously hypertensive rats.

Basal body temperature of spontaneously hypertensive rats (SHR) was found to be significantly elevated compared to normotensive Wistar Kyoto rats (WKR). The hypothermic response to low doses of the alpha 2-receptor agonist clonidine was significantly smaller in SHR compared to WKR. In contrast, the thermoregulatory response of SHR to a non-noxious stressor was heightened. We propose that the elevated basal temperature observed in SHR is not due to an impaired thermolysis but the result of a noradrenaline-mediated hyperreactivity to environmental stress, e.g. handling of the animals during the temperature measurement procedure.