Susic D, Mandal A K, Kentera D
Hypertension. 1984 Mar-Apr;6(2 Pt 1):262-6.
This study describes the effect of a chronic decrease in hematocrit on blood pressure, cardiac output (CO), total peripheral resistance (TPR), and plasma volume in spontaneously hypertensive rats (SHR), and all but plasma volume in normotensive Wistar rats (NWR). Hematocrit was decreased by treatment with either heparin, vitamin K inhibitor ( pelentan ), or by repeated blood letting (BL). The results show that in SHR, a decrease in hematocrit, regardless of how produced, was associated with a significant decrease (p less than 0.01) in blood pressure. Prevention of heparin-induced decrease in hematocrit by repeated transfusions of red blood cells abolished the blood-pressure-lowering effect of heparin. By using combined data on hematocrit and systolic blood pressure in all five SHR groups, a significantly positive correlation and linear regression between hematocrit and blood pressure were obtained. When compared to control untreated SHR, heparin- or pelentan -treated SHR showed a significant (p less than 0.001) decrease in TPR and a significant increase in CO, while in SHR BL, no difference in TPR or CO was found. Plasma or blood volume did not differ among the groups. In NWR, heparin treatment resulted in significantly decreased hematocrit, decreased TPR, and increased CO compared to control normotensive rats. However, blood pressure did not change. Results confirming the authors' previous study and those of other investigators indicate a direct association between hematocrit and systemic hypertension. Lowering the hematocrit can effectively lower an elevated blood pressure. Moreover, the data suggest that heparin or pelentan induces a vasodilator effect that cannot be attributed to a decrease in hematocrit alone.
本研究描述了慢性降低血细胞比容对自发性高血压大鼠（SHR）的血压、心输出量（CO）、总外周阻力（TPR）和血浆容量的影响，以及对正常血压的Wistar大鼠（NWR）除血浆容量外的其他指标的影响。通过使用肝素、维生素K抑制剂（培伦坦）治疗或反复放血（BL）来降低血细胞比容。结果表明，在SHR中，无论通过何种方式降低血细胞比容，均与血压显著降低（p<0.01）相关。通过反复输注红细胞预防肝素诱导的血细胞比容降低，消除了肝素的降压作用。利用所有五个SHR组的血细胞比容和收缩压的综合数据，获得了血细胞比容与血压之间显著的正相关和线性回归关系。与未治疗的对照SHR相比，肝素或培伦坦治疗的SHR的TPR显著降低（p<0.001），CO显著增加，而在SHR BL组中，TPR或CO未发现差异。各组之间的血浆或血容量没有差异。在NWR中，与正常血压对照大鼠相比，肝素治疗导致血细胞比容显著降低、TPR降低和CO增加。然而，血压没有变化。结果证实了作者先前的研究以及其他研究者的研究，表明血细胞比容与系统性高血压之间存在直接关联。降低血细胞比容可有效降低升高的血压。此外，数据表明肝素或培伦坦诱导的血管舒张作用不能仅归因于血细胞比容的降低。
