Condon Michael R, Kim Jiyoun E, Deitch Edwin A, Machiedo George W, Spolarics Zoltán
Department of Surgery, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark 07103, USA.
Am J Physiol Heart Circ Physiol. 2003 Jun;284(6):H2177-84. doi: 10.1152/ajpheart.01069.2002.
With the use of the cecal ligation and puncture model in mice, this study tested whether sepsis-induced decreased erythrocyte deformability is restricted to a subpopulation of cells. Erythrocyte subpopulations were isolated by centrifugal elutriation. Lineweaver-Burk conversion of deformability-response curves to shear stress was used to determine the shear stress at half-maximal cell elongation (K(EI)) and maximal cell elongation (EI(max)). Sepsis decreased erythrocyte deformability in whole blood. K(EI) values were elevated (2.7 vs. 2.1 Pa) and EI(max) values decreased (0.56 vs. 0.50) in sepsis compared with sham mice. K(EI) values for cells eluted at 7 ml/min (smallest and oldest cells) were similar; however, K(EI) values for cells eluted at 8 ml/min were greater in septic than sham animals (2.50 vs. 2.10). Younger and larger subpopulations of erythrocytes (eluted at 9, 10, and 11 ml/min) also showed a tendency of decreased deformability in sepsis. Mean corpuscular hemoglobin content was decreased in cells eluted at 7 and 8 ml/min in sepsis (4.5 and 10.2 pg) compared to sham (7.4 and 11.4 pg) mice. This study indicates that an erythrocyte subpopulation that represents 20% of circulating cells shows the most pronounced decrease in cell deformability during sepsis. Increased rigidity together with decreased corpuscular hemoglobin content in these cells may contribute to microcirculatory dysfunction and immune modulation during sepsis.
利用小鼠盲肠结扎和穿刺模型，本研究测试了脓毒症诱导的红细胞变形性降低是否局限于细胞亚群。通过离心淘析分离红细胞亚群。使用Lineweaver-Burk将变形性-反应曲线转换为剪切应力，以确定细胞伸长率达到最大值一半时的剪切应力（K(EI)）和最大细胞伸长率（EI(max)）。脓毒症降低了全血中红细胞的变形性。与假手术小鼠相比，脓毒症小鼠的K(EI)值升高（2.7对2.1 Pa），EI(max)值降低（0.56对0.50）。以7 ml/min洗脱的细胞（最小和最老的细胞）的K(EI)值相似；然而，脓毒症动物中以8 ml/min洗脱的细胞的K(EI)值高于假手术动物（2.50对2.10）。较年轻和较大的红细胞亚群（以9、10和11 ml/min洗脱）在脓毒症中也显示出变形性降低的趋势。与假手术小鼠（7.4和11.4 pg）相比，脓毒症小鼠中以7和8 ml/min洗脱的细胞的平均血红蛋白含量降低（4.5和10.2 pg）。本研究表明，占循环细胞20%的红细胞亚群在脓毒症期间细胞变形性下降最为明显。这些细胞的刚性增加以及血红蛋白含量降低可能导致脓毒症期间的微循环功能障碍和免疫调节。
