Pathophysiology of Preeclampsia : The Role of Microcirculation

从了解子痫前期病理生理的角度，我们试图评估组织微循环改变的相关因素。在正常妊娠情况下，通过IVVMS观察，发现随着妊娠的提前，结膜内静脉数量增加，血流聚集，全血黏度值在妊娠中期有下降的趋势，外周静脉张力在妊娠晚期有下降的趋势。这些结果表明，母体循环可以通过控制微循环进行自我调节，这与正常妊娠期间血容量的增加是一致的。关于子痫前期妊娠，研究结果总结如下：1)在皮肤和皮下组织冷却后，利用测量深层体温分布的设备进行研究，发现热导率明显下降，血管舒张功能明显紊乱；2)使用IVVMS测量的血流中静脉数量减少，污泥量增加；3)与正常妊娠相比，全血粘度值升高，外周静脉张力升高。这些结果表明，组织微循环紊乱以及血管扩张和静脉扩张的紊乱是子痫前期妇女病理生理变化的决定因素。从细胞生物学的研究发现，子痫前期妇女血清中存在内源性因子，从而对内皮细胞产生较强的细胞毒作用。

From viewpoint of understanding the pathophysiology of preeclampsia, we attempted to assess the factors pertaining to change in tissue microcirculation.In normal pregnancy, the following findings were obtained : 1) The increases in the number of venules and aggregation of blood flow in conjunctiva bulbi were noted with advance in gestation under conditions of the Intra Vital Video Microscopic System (IVVMS) observation, 2) the values of whole blood viscosity tended to decrease in the second trimester of pregnancy, 3) the peripheral venous tone was found to decrease in the third trimester of pregnancy. These findings suggest that the maternal circulation can adjust itself by controlling the microcirculation, in accord with the increase of bloo volume during normal course of pregnancy.With regard to preeclamptic pregnancy, the findings were summarized as follows : 1) The decrease in thermal conductivity and disturbed vasodilatation was evident when studied after cooling in the skin and subcutaneous tissues, by means of the equipment measuring deep body temperature distribution, 2) The decrease in the number of venules and the increase of sludge of blood flow measured using IVVMS were observed, 3) the increase in the value of whole blood viscosity together with increase in the peripheral venous tone were noted when compared with those in normal pregnancy. These findings indicate that the disturbance in the tissue microcirculation and the disturbance of both vasodilatation and venodilatation were the determinant factors characterizing the pathophysiological changes in preeclamptic women.From the study on cell-biology, it was found that there exist the endogeneous factors in the serum of preeclamptic women, thereby making strong cytotoxic effect on endothelial cells.