抄録
We investigated the effects of alcohol on thermoregulatory responses and thermal sensations during cold exposure in humans. Eight healthy men participated in this study. Experiments were conducted twice for each subject at a room temperature of 18 °C. After a 30-min resting period, the subject drank either 15% alcohol (alcohol session) at a dose of 0.36 g/kg body weight or an equal volume of water (control session). Deep body temperature gradually decreased throughout 90-min measurement both in the alcohol and control sessions (from 36.9 ± 0.1 °C to 36.6 ± 0.1 °C) without any statistically significant differences. Metabolic rate in the control session started to increase 30 min after the onset of measurement. On the other hand, in the alcohol session, metabolic rate remained unchanged in spite of a decrease in body core temperature. Whole body cold sensation became strong in the control session during cold exposure, whereas it changed to "not cold at all" after alcohol drinking, which would inhibit the behavioral regulation, if available. In the previous study we have already shown that both autonomic and behavioral thermoregulation is also modulated to decrease body temperature in hot environment (Yoda et al., 2005). Thus, alcohol influences all thermoregulatory mechanisms including behavior so as to decrease body core temperature. These results suggest that alcohol affects some elements common to all the effector mechanisms, most presumably thermosensitive neurons in the brain. [J Physiol Sci. 2006;56 Suppl:S229]
