Mchedlishvili G, Varazashvili M, Mamaladze A, Momtselidze N
Microcirculation Research Center, I. Beritashvili Institute of Physiology, Tbilisi, Republic of Georgia.
Microvasc Res. 1997 May;53(3):201-10. doi: 10.1006/mvre.1997.2012.
Various manifestations of blood flow structuring were investigated in rabbit cerebral cortex capillaries, which possess the most narrow lumina of all parts of the body. Blood flow structuring in the capillaries was characterized by the presence of a stable and comparatively large parietal plasma layer, which changed insignificantly under control and ischemic conditions, but disappeared when blood stasis developed inside the capillaries. The axial core of the blood flow in the capillaries, which occupied almost two-thirds of the intracapillary volume under normal conditions, consisted of significantly deformed (stretched along the microvessels' axes) and nonaggregated erythrocytes. During ischemia the shape of the erythrocytes did not change appreciably; only the blood plasma intervals between them increased significantly, demonstrating reduction of the local hematocrit. During primary blood stasis caused by enhanced intravascular erythrocyte aggregation, typical blood flow structuring became significantly disturbed: red cells filled the whole, or almost the whole, capillary lumina and did not leave visible space for plasma inside the microvessel lumina. We concluded that normal blood flow structuring is a deciding factor in the blood rheological properties of microvessels. Its disturbance, caused by fast accumulation of erythrocytes in the capillary lumina, results in blood rheological disorders and in a slow down to a full stop of the blood flow, despite a preserved arteriolovenular pressure difference.
在兔脑皮质毛细血管中研究了血流结构的各种表现，兔脑皮质毛细血管是身体所有部位中管腔最窄的。毛细血管中的血流结构特点是存在一个稳定且相对较大的壁旁血浆层，在对照和缺血条件下该血浆层变化不明显，但当毛细血管内出现血液淤滞时会消失。正常情况下，毛细血管内血流的轴向核心几乎占据毛细血管容积的三分之二，由明显变形（沿微血管轴拉长）且不聚集的红细胞组成。缺血期间红细胞形状变化不明显；只是它们之间的血浆间隙显著增加，表明局部血细胞比容降低。在由血管内红细胞聚集增强引起的原发性血液淤滞期间，典型的血流结构受到明显干扰：红细胞充满整个或几乎整个毛细血管腔，在微血管腔内没有为血浆留下可见空间。我们得出结论，正常的血流结构是微血管血液流变学特性的决定性因素。其由红细胞在毛细血管腔内快速积聚引起的紊乱会导致血液流变学障碍，以及尽管保留了动静脉压差但血流减慢直至完全停止。
