Shore A C, Sandeman D D, Tooke J E
Clinical Microvascular Unit, Postgraduate Medical School, University of Exeter, United Kingdom.
Am J Physiol. 1993 Sep;265(3 Pt 2):H820-3. doi: 10.1152/ajpheart.1993.265.3.H820.
Moderate autoregulation of capillary pressure occurs during changes in arterial and/or venous pressure in animals. Whether an increase in systemic blood pressure is transmitted to capillaries in humans is unknown. Eight healthy volunteers performed isometric handgrip exercise (30% of maximum) while nailfold capillary pressure (CP) and digital arterial blood pressure (DBP) were measured in the contralateral hand. CP was measured for 40 s before exercise and 40-100 s during exercise. Only experiments with no change in pipette position and no artifactual changes in flow were accepted. Basal DBP was stable [91.5 +/- 12.7 mmHg (-40 to -20 s basal) and 91.3 +/- 11.8 mmHg (-20 to 0 s basal)], and isometric exercise increased DBP [100.4 +/- 13.9 mmHg (0-20 s exercise) and 103.1 +/- 15.3 mmHg (20-40 s exercise); P < 0.05]. CP was unchanged during the first 40 s of exercise [18.9 +/- 4.9 mmHg (-40 to 20 s basal), 18.9 +/- 5.2 mmHg (-20 to 0 s basal), 18.4 +/- 4.7 mmHg (0-20 s exercise), and 18.3 +/- 5.3 mmHg (20-40 s exercise)] and remained unchanged for up to 100 s (n = 5), despite a continued elevation of DBP. These data suggest that protective mechanisms minimize the transmission of increases in systemic blood pressure to the capillary bed in humans.
在动物中，毛细血管压力存在适度的自动调节，发生于动脉和/或静脉压力变化期间。系统性血压升高是否会传递至人体毛细血管尚不清楚。八名健康志愿者进行等长握力运动（最大力量的30%），同时测量对侧手部的甲襞毛细血管压力（CP）和指动脉血压（DBP）。在运动前40秒和运动期间40 - 100秒测量CP。仅接受移液管位置无变化且流量无人为变化的实验。基础DBP稳定[基础期 - 40至 - 20秒时为91.5±12.7 mmHg，基础期 - 20至0秒时为91.3±11.8 mmHg]，等长运动使DBP升高[运动期0至20秒时为100.4±13.9 mmHg，运动期20至40秒时为103.1±15.3 mmHg；P < 0.05]。运动的前40秒CP无变化[基础期 - 40至20秒时为18.9±4.9 mmHg，基础期 - 20至0秒时为18.9±5.2 mmHg，运动期0至20秒时为18.4±4.7 mmHg，运动期20至40秒时为18.3±5.3 mmHg]，并且在长达100秒内保持不变（n = 5），尽管DBP持续升高。这些数据表明，保护机制可将系统性血压升高传递至人体毛细血管床的情况降至最低。
