Effects of posture on peripheral vascular responses to lower body positive pressure
Effects of posture on peripheral vascular responses to lower body positive pressure
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DOI：
10.1152/ajpheart.00462.2006
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发表时间：
2007-07-01
影响因子：
4.8
通讯作者：
Ichinose, Masashi
中科院分区：
文献类型：
--
作者：
Nishiyasu, Takeshi;Hayashida, Shigeko;Ichinose, Masashi
我们验证了这样一种假设，即外周血管对下体正压(LBPP)的反应取决于受试者的姿势。我们测量了11名受试者(男9名，女2名)在卧位和直立状态下的心率、每搏输出量、平均动脉压、腿部和前臂血流量，以及腿部(LVC)和前臂(FVC)的血管电导。平均动脉压与下体负压的增加成正比，仰卧位的平均动脉压大于直立位的。卧位受试者应用下体负压试验时心率不变，而直立受试者心率降低。LBPP降低仰卧位受试者的腿部血流量和LVC[LVC分别为4.8(SD 4.0)、3.6(SD 3.5)和1.4(SD 1.8)m l中心点分钟(-1)中心点mm Hg(-1)、25和50 mm Hg；而立位LVC分别为2.0(SD 1.2)、3.4(SD 3.4)、3.0(SD 2.0)ml中心点min(-1)、中心点mm Hg(-1)，P<；0.05。卧位受试者前臂血流量和FVC均下降[FVC分别为1.3(SD 0.6)，1.0(SD 0.4)和0.9(SD 0.6)ml中心点min(-1)中心点mm Hg(-1)；P<；0.05]，而立位受试者前臂血流量和FVC无明显变化[FVC分别为0.7(SD 0.4)，0.7(SD 0.4)和0.6(SD 0.5)ml中心点min(-1)中心点mm Hg(-1)]。总之，这些发现表明，腿部血管对LBPP应用的反应是姿势依赖的，当受试者采取直立姿势时，下肢和上肢的反应是不同的。
We tested the hypothesis that peripheral vascular responses (in the lower and upper limbs) to application of lower body positive pressure (LBPP) are dependent on the posture of the subjects. We measured heart rate, stroke volume, mean arterial pressure, leg and forearm blood flow (using the Doppler ultrasound technique), and leg (LVC) and forearm (FVC) vascular conductance in 11 subjects (9 men, 2 women) without and with LBPP (25 and 50 mmHg) in supine and upright postures. Mean arterial pressure increased in proportion to increases in LBPP and was greater in supine than in upright subjects. Heart rate was unchanged when LBPP was applied to supine subjects but was reduced in upright ones. Leg blood flow and LVC were both reduced by LBPP in supine subjects [LVC: 4.8 (SD 4.0), 3.6 (SD 3.5), and 1.4 (SD 1.8) ml center dot min(-1)center dot mmHg(-1) before LBPP and during 25 and 50 mmHg LBPP, respectively; P < 0.05] but were increased in upright ones [LVC: 2.0 (SD 1.2), 3.4 (SD 3.4), and 3.0 (SD 2.0) ml center dot min(-1)center dot mmHg(-1), respectively; P < 0.05]. Forearm blood flow and FVC both declined when LBPP was applied to supine subjects [FVC: 1.3 (SD 0.6), 1.0 (SD 0.4), and 0.9 (SD 0.6) ml center dot min(-1)center dot mmHg(-1), respectively; P < 0.05] but remained unchanged in upright ones [FVC: 0.7 (SD 0.4), 0.7 (SD 0.4), and 0.6 (SD 0.5) ml center dot min(-1)center dot mmHg(-1), respectively]. Together, these findings indicate that the leg vascular response to application of LBPP is posture dependent and that the response differs in the lower and upper limbs when subjects assume an upright posture.