Increased hand blood flow limits other skin vasodilation

Abstract

1. 1. To examine whether the increased hand blood flow (BF), mainly arteriovenous anastomoses (AVA) flow, limits an increase in other skin BF during thermal load, 7 healthy male subjects were exercised for 25 min and then rested for 20 min in wrist occlusion (OCCL) and control experiments (CONT), respectively. 2. 2. In OCCL, both wrists were occluded at pressure of 250 mmHg from the 15th min of exercise. 3. 3. In CONT, the wrists were free throughout the experiment. Finger and forearm skin temperature greatly increased in CONT, but did not rise in OCCL. 4. 4. Suppressed hand BF in OCCL induced compensatory increases of skin BF and sweat rate in the chest at least. 5. 5. However, wrist occlusion induced a significant rise in esophageal temperature and a significant fall in mean arterial pressure (MAP). 6. 6. These results suggest that the rising hand BF greatly contributes to limit the increase in other skin BFs without any fall of MAP during thermal load.