Study of cold-induced vasodilation due to cold exposure / 体力科学

ABSTRACT

This study was carried out to examine the following. 1) For 20 adult males in summer, cold-induced vasodilation (CIVD) immersed in ice water (ice water CIVD) and CIVD exposed to cold air of 0°C, -5°C and -10°C (cold air CIVD) were compared. The blood pressure was measured and examined during the course of measuring ice water CIVD and -10°C cold air CIVD. 2) -10°C cold air CIVD was measured in summer and in winter for 40 males.<BR>The results for 1) and 2) are summarized as follows.<BR>1. Definite effects of the difference in thermal transmission rate was observed between cold air CIVD and ice water CIVD. Finger skin temperature fell as the temperature at cold air CIVD dropped to 0, -5 and -10°C. At -10°C cold air CIVD where the drop of skin temperature was greatest, the temperature at first rise (TFR) was higher, time of temperature rise (TTR) was longer and amplitude of temperature (AT) was greater, compared with the respective values at ice water CIVD. However, no difference was observed in mean skin temperature (MST) during the exposure. Individual difference in values at cold air CIVD was greater than that at ice water CIVD.<BR>2. The time of maximum rise of blood pressure response after cold exposure was 5 minutes at ice water CIVD and 20 minutes at -10°C cold air CIVD. The rate of blood pressure rise at -10°C cold air CIVD was significantly greater. The time when the rise of blood pres-sure reached the maximum was identical with the time when the skin temperature became lowest.<BR>3. At -10°C cold air CIVD, MST and TFR were higher and TTR shorter in winter than those in summer. At ice water CIVD, the values in summer were higher for MST and TFR and shorter for TTR as mentioned previously.<BR>4. The temperature before -10°C cold air CIVD (TB) showed a significant correlation with MST and TFR, though not with TTR.<BR>5. A comparison of these results with Watanuki et al.'s report reveal some differences.