FLOW DYNAMICS OF HUMAN SICKLE ERYTHROCYTES IN THE MESENTERIC MICROCIRCULATION OF THE EXCHANGE-TRANSFUSED RAT
FLOW DYNAMICS OF HUMAN SICKLE ERYTHROCYTES IN THE MESENTERIC MICROCIRCULATION OF THE EXCHANGE-TRANSFUSED RAT
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DOI：
10.1016/0026-2862(87)90050-1
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发表时间：
1987-09-01
影响因子：
3.1
通讯作者：
LESSIN, LS
中科院分区：
文献类型：
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作者：
KURANTSINMILLS, J;JACOBS, HM;LESSIN, LS
为了分析完整动物模型中镰状细胞的微血管流变学，在环境条件下等容交换输注人正常（血红蛋白AA）或镰状细胞（血红蛋白SS）红细胞（O型血）或自体红细胞，测定异体或自体细胞对受体(a)血流动力学和呼吸、(b)血气和(c)酸碱状态的影响。自体红细胞或血红蛋白AA或血红蛋白SS红细胞置换输注大鼠，除HbSS细胞组出现心动过速外，实验期间平均动脉血压、中心静脉压、呼吸速率、血液pH、pCO2和pO2均稳定。动静脉氧含量在三组动物中有所不同，但尽管如此，表明在研究条件下组织氧供应充足。三组大鼠的酸碱状态也相似。采用活体显微镜观察交换输血大鼠肠系膜微循环中红细胞的流动动力学。自体红细胞在16 ~ 30 μ m范围内的时间平均速度。在单个无分支小动脉中，M （id）血管范围为1.07至125 mm/秒，具有不同的通量和壁剪切率。单个HbAA细胞在15 ~ 35 μ m内的时间平均速度。M小动脉的壁剪切速率在1.16 ~ 1.24 mm/秒之间，与自体细胞的壁剪切速率相似。对于大鼠和人HbAA红细胞，流动动力学表明细胞在流动条件下具有正常的剪切依赖性和可变形性特征。镰状细胞的时间平均速度为0.384至0.452 mm/秒，在10- 35-.mu中壁剪切率较低。单个无分支的小动脉，体积流量减少了三倍。在一些小动脉中，具有高轴比和低变形能力的镰状细胞与内皮表面表现出明确的粘附，在这些部位停留几秒钟，直到被血流力移动。在单个无分支血管内或微血管分叉处，低变形性、高轴比的镰状椭圆细胞和镰状棘细胞阻碍血流，停留时间为2 ~ 88秒，从而引起瘀血。这些数据说明了镰状细胞的微血管流动行为，并证明了当镰状细胞通过微循环的连续段时可能导致的流变不平衡状态。
To analyze the microvascular rheology of sickle cells in an intact animal model, rats were isovolemically exchange transfused with human normal (hemoglobin AA) or sickle (hemoglobin SS) erythrocytes (blood group O) or autologous red cells under ambient conditions, and the effects of the heterologous or autologous cells on (a) hemodynamics and respiration, (b) blood gases, and (c) acid-base status of the recipients were determined. Exchange transfusion of rats with autologous red cells or hemoglobin AA or hemoglobin SS erythrocytes was associated with stable mean arterial blood pressure, central venous pressure, respiration rate, blood pH, pCO2, and pO2 during the experimental period, except for tachycardia among the group of rats that received HbSS cells. Arteriovenous oxygen content varied among the three groups of animals, but, nonetheless, suggested adequate tissue oxygen supply under the conditions of the study. Acid-base status also was similar in the three groups of rats. The exchange-transfused rats were utilized to investigate the flow dynamics of red cells in the mesenteric microcirculation by applying intravital microscopy. Time-averaged velocities of the autologous red cells in 16- to 30-.mu.m (id) vessels ranged from 1.07 to 125 mm/sec in single unbranched arterioles with varying flux and wall shear rates. Time-averaged velocities of the HbAA cells in single 15- to 35-.mu.m arterioles ranged from 1.16 to 1.24 mm/sec with wall shear rates similar to the estimates for the autologous cells. For both rat and human HbAA RBCs, the flow dynamics were indicative of normal shear-dependent and deformability characteristics of the cells under the flow conditions. Sickle cells exhibited time-averaged velocities of 0.384 to 0.452 mm/sec, lower wall shear rates in 10- to 35-.mu.m single unbranched arterioles, and three times less volumetric flux. In some arterioles, sickle cells with high axial ratio and low deformability showed definite adhesion to the endothelial surface, residing at such sites for several seconds until dislodged by the force of flow. Within single unbranched vessels or at microvascular bifurcations, sickle elliptocytes and sickle echinocytes with low deformability and high axial ratio obstructed flow and exhibited residence times of 2 to 88 sec, thereby causing stasis. These data illustrate the microvascular flow behavior of sickle cells and demonstrate the rheological disequilibrium state that can result as sickle cells course through successive segments of the microcirculation.