Overbeck H W, Pamnani M B
Proc Soc Exp Biol Med. 1975 Nov;150(2):331-6. doi: 10.3181/00379727-150-39030.
To study limb vascular responses to plasma hypoosmolality in man, we infused test solutions of hypoosmolar NaCl (145 mOsm/kg) and control solutions of isosmolar NaCl (290 mOsm/kg) into the brachial arteries of 14 mornotensive and 13 essential hypertensive patients. Limb blood pressures were monitored, limb blood flow was measured by indicator-dilution, and limb vascular resistance was calculated as mmHg/ml flow/min/100 cm3 limb volume. The infusions did not significantly change systemic plasma osmolality, sodium concentration, or blood pressure. Compared to control infusions, the hypoosmolar infusions decreased limb venous plasma osmolality and serum sodium concentrations by an average of 12 mOsm/kg and 7 mEq/1, respectively. Compared to control infusions, limb venous serum concentrations of potassium, calcium, magnesium, or blood hematocrit were not altered by the hypoosmolar infusions. In response to the hypoosmolar infusions, limb resistance increased by 28% in normotensives and by 26% in hypertensives. We conclude that the acute local vascular response to a small reduction in plasma osmolality in the limb of man is a large increase in vascular resistance. We found no evidence for abnormal responses to plasma hypoosmolality in essential hypertensives.
为研究人体肢体血管对血浆低渗状态的反应，我们将低渗氯化钠（145毫渗摩尔/千克）测试溶液和等渗氯化钠（290毫渗摩尔/千克）对照溶液注入14名血压正常者和13名原发性高血压患者的肱动脉。监测肢体血压，通过指示剂稀释法测量肢体血流量，并将肢体血管阻力计算为毫米汞柱/毫升血流量/分钟/100立方厘米肢体体积。输注并未显著改变全身血浆渗透压、钠浓度或血压。与对照输注相比，低渗输注使肢体静脉血浆渗透压和血清钠浓度分别平均降低12毫渗摩尔/千克和7毫当量/升。与对照输注相比，低渗输注并未改变肢体静脉血清钾、钙、镁浓度或血细胞比容。对低渗输注的反应是，血压正常者的肢体阻力增加28%，高血压患者的肢体阻力增加26%。我们得出结论，人体肢体血浆渗透压轻度降低时的急性局部血管反应是血管阻力大幅增加。我们未发现原发性高血压患者对血浆低渗状态有异常反应的证据。
