Durussel J J, Berthault M F, Guiffant G, Dufaux J
Laboratoire de Biorhéologie et d'Hydrodynamique Physico-chimique, CNRS URA 343, Université Paris, France.
Acta Physiol Scand. 1998 May;163(1):25-32. doi: 10.1046/j.1365-201x.1998.00342.x.
This study presents the effects of red blood cell (RBC) hyperaggregation on the blood flow and pressure in the rat mesentery and cremaster network. We exclusively studied in situ non-vasodilated organs, in order to maintain the physiological regulation mechanisms. Dextran 500 was injected at different concentrations to increase RBC aggregation. The aggregation rate was measured on very small blood samples with an erythroaggregameter (SEFAM) which evaluated the disaggregating shear stress (tau D) needed to break the RBC aggregates. Microscopic observations and laser Doppler velocimetry were used to quantify the flow rate. The plasmatic dextran concentration (C) increase had different correlated effects: for example, tau D increased from 3 dynes cm-2 (for the control sample) to 14 dynes cm-2 (for C = 75 microM L-1); the flow rate was reduced threefold and very large aggregates were observed in the venules; the arteriolar pressure increased while venular pressure decreased. In order to differentiate the effects of RBC hyperaggregation from those of plasma hyperviscosity (due to dextran 500) on microcirculatory blood flow, we injected an RBC antiaggregating drug (troxerutine) (50 or 100 mg kg-1 i.v.). The consequences were a high reduction for (tau D) (from 14 dynes cm(-2)-9 dynes cm-2), smaller aggregates and higher blood flow in the venules. No effect of troxerutine was observed on plasma viscosity (plasma control: 1.9 cP with or without troxerutine; plasma with dextran at C = 75 microM L-1: 2.45 cP with or without troxerutine). The results strongly suggest that RBC aggregation has a significant influence on blood flow rate in the microcirculatory network.
本研究呈现了红细胞（RBC）过度聚集对大鼠肠系膜和提睾肌网络中血流及血压的影响。我们专门研究了原位非扩张器官，以维持生理调节机制。注射不同浓度的右旋糖酐500以增加红细胞聚集。使用红细胞聚集仪（SEFAM）在非常小的血样上测量聚集率，该仪器评估破坏红细胞聚集体所需的解聚剪切应力（tau D）。通过显微镜观察和激光多普勒测速法对流速进行量化。血浆右旋糖酐浓度（C）的增加具有不同的相关效应：例如，tau D从3达因/平方厘米（对照样本）增加到14达因/平方厘米（对于C = 75微摩尔/升）；流速降低了三倍，并且在小静脉中观察到非常大的聚集体；小动脉血压升高而小静脉血压降低。为了区分红细胞过度聚集与血浆高粘度（由于右旋糖酐500）对微循环血流的影响，我们静脉注射了一种红细胞抗聚集药物（曲克芦丁）（50或100毫克/千克）。结果是（tau D）大幅降低（从14达因/平方厘米降至9达因/平方厘米），聚集体变小，小静脉中的血流增加。未观察到曲克芦丁对血浆粘度有影响（血浆对照：无论有无曲克芦丁均为1.9厘泊；含右旋糖酐且C = 75微摩尔/升的血浆：无论有无曲克芦丁均为2.45厘泊）。结果强烈表明红细胞聚集对微循环网络中的血流速率有显著影响。
