抄録
We examined the sex difference in the relationship between muscle blood flow and muscle tissue oxygenation level following arterial occlusion with and without static handgrip exercise. Healthy young subjects (9 females and 9 males) participated in the present study. We measured brachial arterial blood flow by ultrasound Doppler flowetry before occlusion and after cuff release following arterial occlusion for 2, 4, or 6 min. We also measured muscle tissue oxygen saturation (StO2) before, during and after occlusions with near infrared spectroscopy, and determined the relationship between StO2 just before cuff release and muscle blood flow response. The relationship between StO2 and muscle blood flow following occlusion with static handgrip exercise at 20% maximal voluntary contraction for 2 or 3 min was also determined. StO2 decreased during occlusion in dependence upon the duration of occlusion and exercise. Brachial blood flow increased with decrease in StO2, and the increase in brachial blood flow at a given decrease in StO2 was larger following occlusion with exercise than without exercise, suggesting that exercise augments the blood flow response to increased oxygen demand. The decrease in StO2 was much larger in males than females in all conditions, while percent increase in brachial blood flow in males was not different from females. These suggest that there exists sex difference in muscle blood flow regulation. The increase in muscle blood flow at a given decrease in StO2 was larger in females than males. [J Physiol Sci. 2008;58 Suppl:S160]
