Effect of temperature on reactive hyperemia in skeletal muscle

¹ Department of Physiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

Circulatory reactivity to vascular occlusion for periods of 30, 60, and 120 sec was determined on eight isolated canine gracilis muscles under normothermic and hypothermic conditions (approx. 37.5 C, 25 C, 18 C, and 7 C). Control blood flow either increased or decreased when the temperature was lowered but was quite stable at each temperature step. The amount of reactive hyperemia always decreased with hypothermia and was statistically independent of effect from the control blood flow as the temperature was lowered. Recovery from reactive hyperemia required approximately the same time for the three periods of occlusion at each temperature step. The effect of hypothermia on control blood flow appears to determine the time required for recovery from reactive hyperemia.