[The relationship between temperature adaptation and the effect of noradrenaline on central control of...

In rats cold--adapted (1--3 degrees C) or warmth--adapted (26--28 degrees C) for 4--5 weeks, the body temperature, oxygen uptake, electric muscle activity were continuously recorded before and after intraventricular injection of noradrenaline (NA) at a total volume of 5--8 mcl. At the ambient temperature of 25 degrees C, extremely small doses (5--8 mcg) of NA raised the body temperature due to shivering. Injections of NA were more effective in the cold--adapted rats. Injections of NA at a low ambient temperature (10 degrees C) evoked greater thermoregulatory responses in the warmth-adapted rats.