Metabolic Adaptation to Cold.
Rept. no. 3 (Final), Sep 68-Sep 69,
YONSEI UNIV SEOUL (REPUBLIC OF KOREA) DEPT OF PHYSIOLOGY
Pagination or Media Count:
Experiments on thermoregulatory responses to cold immersion stimulus were carried out in September, 1968 summer studies and February, 1969 winter studies. Eight each of ama and control subjects were selected at random from a same community in Yong-Do Island, Pusan. The rate of fall in muscle temperature of forearm during a 30 minutes immersion in 6C water bath was significantly slower in the ama in winter and was about the same in the two groups in summer. However, the magnitude of change in the skin temperature and the heat fluxes observed during immersion period was not significantly different either between groups or between seasons. Both finger blood flow and skin temperature during one hour immersion in 6C water bath decreased significantly in the ama as compared to the control. The magnitude of cold-induced vasodilatation during immersion period was significantly greater in the control in winter. The magnitude of reactive hyperemia after a 5 minutes arterial occlusion in both air and 15C water bath was significantly lower in the ama than in the control. In control subjects, post-occluded blood flow to resting values in the air was faster in the ama than in the control but was the same in the two groups. The results suggest that vasoconstrictor tone increased in the ama in winter, indicating the development of vascular adaptation as a part of cold acclimatization. Author
- Anatomy and Physiology