抄録
To investigate whether immersion of the forearm in water containing high concentration CO2 (CO2-water) influences local muscle O2 consumption (MO2) and forearm blood flow (BFmuscle) near-infrared spectroscopy (NIRS) was carried out. Six healthy female volunteers (21-22 years) seated in upright position were instrumented on the right lower arm with a laser Doppler flowmetry probe for recording skin blood flow (BFskin), a NIRS-probe for recording muscle hemoglobin (Hb) contents (oxy-Hb, total-Hb). Blood flow of the forearm was restricted by comprising the inflatable cuff on the upper arm to perform three consecutive venous occlusions (<50 mmHg for 20 s) followed by an arterial occlusion (<280 mmHg, 50 s). MO2 was determined by evaluating the slope of linear regression line of oxy-Hb decreases during arterial occlusion, and BFmuscle was determined by the rate of increase of total-Hb during venous occlusion. Bath water (30°C) exchanged for another, i.e. tap water (CO2<20 ppm) into CO2 water (860-990 ppm) or vice versa, every about 20 min. All subjects reported that CO2-water was warmer than the tap water. The BFskin was significantly 3.6 times larger during CO2-water immersion than tap water immersion. MO2 and BFmuscle during CO2-water immersion was respectively 15% and 32% larger than during tap-water immersion. Results suggest that the artificial CO2-water bathing may increase muscle-blood flow as well as skin blood flow and stimulate the muscle metabolism. [J Physiol Sci. 2007;57 Suppl:S188]
