体温調節に対するアルコールの影響

It is well known that alcohol elicits decreases in body temperature (Wasielewski and Holloway. 2001). It is generally considered that alcohol directly acts on cutaneous blood vessels to induce vasodilation, that is, to increase heat dissipation. On the contrary, alcohol that freely crosses blood brain barrier, might act on thermoregulatory center itself so that body temperature was regulated at lower level than normal. In this study, to test this possibility we investigated that the effects of alcohol on thermoregulatory responses and thermal sensations in humans. Six healthy male subjects participated in this study. Experiments were conducted twice for each subject at a room temperature of 33°C. After 30 min resting period the subject drank either 15% alcohol (alcohol session) or water (water session) at a volume of 3 ml/kgwt. Skin blood flow and sweat rate of the chest were measured. Deep body temperature was measured with a telemetry. In response to alcohol drinking sweat rate increased and reached the peak at 20 min after drinking. Deep body temperature decreased after the onset of sweating. Subjects reported increased hot sensation which temporary paralleled with change in sweat rate. These results suggest that in addition to the direct peripheral effect alcohol would act on thermoregulatory center so as to lower body temperature. (This study was approved by the ethical committee of Waseda Univ.) [Jpn J Physiol 54 Suppl:S230 (2004)]