Rearing rats (Rattus norvegicus) at 30 degrees C does not alter sensitivity to noradrenaline.

Rats reared from birth at 30 degrees C show a permanent deficit in body temperature regulation. To test the ability of heat-reared rats to respond to an adrenergic drive, carbon dioxide production was measured at five doses of noradrenaline in rats reared at either 20 or 30 degrees C. Noradrenaline-induced carbon dioxide production was greater at all doses in 20 degrees C rats, but sensitivity to noradrenaline was the same in heat-reared and control animals. These findings support the conclusion that the thermoregulatory deficit induced by heat rearing is due to a change induced in the nervous system.