Thermosensitivity changes in cold-adapted rats

Cold-adapted rats (unlike non-adapted animals) respond to an acute exposure to external cold by an overshoot increase in metabolic rate and a paradoxi cal increase in body core temperature. In contrast to external cooling, int ernal cooling with the aid of a chronically implanted intravenous heat exch anger elicited comparable increase in metabolic rate, coupled with a large fall in core temperature. It is concluded that cold adaptation alters perip heral thermosensitivity (enhances cold sensitivity), while the thermosensit ivity of the core is not affected by the adaptation process. (C) 2000 Elsev ier Science Ltd. All rights reserved.