Importance of noradrenaline in cold adaptation

Abstract

Noradrenaline (300 µg/kg) was injected daily for 45 days in a group of 15 rats. At the end of this period O₂ consumption and rectal temperature responses to noradrenaline (200 µg/kg) were measured at 30 C in these animals as well as in cold-acclimated and control groups. Noradrenaline-treated and cold-acclimated animals have a larger O₂ and rectal temperature increase than the control. At –20 C the noradrenaline-treated and cold-adapted rats maintained a higher rectal temperature and survived longer than the control group. These results indicate that repeated injections of noradrenaline to animals at room temperature can produce some cold acclimation and suggest that noradrenaline may be of importance in acquiring acclimation in rats exposed to cold.