Kilgour R D, Carranza A, Findlay R
Department of Exercise Science, Concordia University, Montreal, Quebec, Canada.
Aviat Space Environ Med. 1997 Jan;68(1):46-50.
Forearm blood flow (FBF) was measured by electrical impedance plethysmography in order to identify the influence of local cooling of the contralateral hand after 3 min of arterial occlusion. Ten volunteers (six females, four males) were randomly assigned to the following three experimental conditions on separate days: a) 6 min of local hand cooling (5-7 degrees C); b) 3 min of arterial occlusion of the forearm; and c) combined arterial occlusion and local cooling.
All subjects experienced the typical pressor response during 6 min of hand cooling as evidenced by the significant increase (p < and = 0.05) in heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP). The FBF responses demonstrated an immediate increase (p < and = 0.05) within the first 30 s of hand submersion and then progressively declined over the next 5 min. The forearm vascular resistance (FVR = MAP/FBF) made an initial drop during the first 30 s of cooling and then gradually rose to reach peak levels between 5-6 min of cooling. With respect to the hyperemic response, FBF significantly increased (p < and = 0.05) from baseline (mean +/- SEM; 1.09 +/- 0.18 ml x 100 ml-1.min-1) and achieved peak levels (6.75 +/- 0.64 ml x 100 ml-1.min-1) within the initial 30 s of the post-occlusion period. Thereafter, FBF declined rapidly by 30-60 s (1.67 +/- 0.29 ml x 100 ml-1.min-1) and 60-90 s (1.26 +/- 0.33 ml x 100 ml-1.min-1) of the post-occlusion period.
When the reactive hyperemic response was coupled with hand cooling, FBF increased above baseline values and reached peak levels during the initial 30 s of the post-occlusion period. However, the magnitude of the hyperemic response was significantly lower in the cold condition compared to the hyperemia alone (3.20 +/- 0.42 vs 6.75 +/- 0.64 ml x 100 ml-1.min-1; p < and = 0.05). Clearly, the overall sympathetic response to local cooling had an overriding effect on the factors that promote peripheral vasodilation following brief periods (3 min) of arterial occlusion.
采用电阻抗体积描记法测量前臂血流量（FBF），以确定在动脉闭塞3分钟后对侧手部局部冷却的影响。10名志愿者（6名女性，4名男性）在不同日期被随机分配到以下三种实验条件：a）手部局部冷却6分钟（5 - 7摄氏度）；b）前臂动脉闭塞3分钟；c）动脉闭塞与局部冷却相结合。
所有受试者在手部冷却6分钟期间均出现典型的升压反应，心率（HR）、收缩压（SBP）和舒张压（DBP）显著升高（p≤0.05）。FBF反应显示，手部浸入的前30秒内立即增加（p≤0.05），然后在接下来的5分钟内逐渐下降。前臂血管阻力（FVR = MAP/FBF）在冷却的前30秒内最初下降，然后在冷却5 - 6分钟之间逐渐上升至峰值水平。关于充血反应，FBF从基线（平均值±标准误；1.09±0.18 ml×100 ml⁻¹·min⁻¹）显著增加（p≤0.05），并在闭塞后最初30秒内达到峰值水平（6.75±0.64 ml×100 ml⁻¹·min⁻¹）。此后，FBF在闭塞后30 - 60秒（1.67±0.29 ml×100 ml⁻¹·min⁻¹）和60 - 90秒（1.26±0.33 ml×100 ml⁻¹·min⁻¹）迅速下降。
当反应性充血反应与手部冷却相结合时，FBF高于基线值增加，并在闭塞后最初30秒内达到峰值水平。然而，与单独充血相比，寒冷条件下充血反应的幅度显著降低（3.20±0.42 vs 6.75±0.64 ml×100 ml⁻¹·min⁻¹；p≤0.05）。显然，对局部冷却的整体交感神经反应对促进短暂（3分钟）动脉闭塞后外周血管舒张的因素具有压倒性影响。
