红细胞是维持生命最重要的细胞之一, pH是影响其结构功能的重要因素。 结合人血液中存在血清白蛋白, 且可能会对红细胞起作用的特点, 在模拟人体内血液中血清白蛋白与血红蛋白摩尔比值的条件下, 研究pH协同血清白蛋白对单个活态人红细胞的形态, 细胞膜变形能力及胞内血红蛋白结构变化的影响。 结果显示, 不同pH下, 红细胞的表面形态、 膜变形能力的变化规律与其胞内血红蛋白结构的变化有关: 在pH 4.14, 4.76, 10.18时, 红细胞胞内血红蛋白螺旋结构的减少、 疏水性氨基酸的暴露, 血红素珠蛋白结合状态的改变, 影响了血红蛋白结构的稳定性, 从而导致红细胞的结构发生变化, 其形态、 膜变形能力与正常值相比, 变化结果显著。 而在pH 6.51和7.80下, 血红蛋白的拉曼谱结果并未发现有上述变化情况, 胞内血红蛋白的结构没有发生改变, 红细胞的形态、 膜变形能力也接近于正常值。 在pH 5.49和8.76下, 红细胞的表面形态和膜变形能力都有不同程度的变差, 但其胞内血红蛋白的结构并没有改变, 提示红细胞的形态和变形能力的改变可能是可逆的。 结果表明, pH协同血清白蛋白的作用下, 血清白蛋白能对红细胞起保护作用, 增强红细胞调节、 缓冲环境pH变化的能力。 研究结果全面地揭示了在模拟人体内血液中血清白蛋白与血红蛋白摩尔比值的情况下, 红细胞结构功能的变化情况, 不仅有助于阐明红细胞在有关生理、 病理状态下的结构与功能的变化, 而且对其临床表现与有关防治对策都有重要的指导意义。

In the present work, a cell environment which mimicked the real body environment according to the concentration radio between serum albumin and hemoglobin was built, and the cell morphology, the membrane deformation capacity, and the structure of intracellular hemoglobin of single human living erythrocyte under the effect of pH and serum albumin were studied. It was found that at different suspension pH, the magnitude of variations in cell shape and membrane deformation capacity changes with the structural changes of the intracellular hemoglobin. At pH 4.14, 4.76 and 10.18, the loss of helical structure for hemoglobin, exposing of the hydrophobic amino acid in the globin chains, and changing of the combination of heme and globin, would completely destroy the stability of hemoglobin’s structure, which seriously changes RBC’s morphology and membrane deformation capacity. While at pH 6.51 and 7.80, the Raman spectra of erythrocytes are found to have no such changes, indicating that the structure of intracellular hemoglobin was not varied, thus the cell morphology and membrane deformation capacity are quite close to the normal values. At pH 5.49 and 8.76, RBC’s morphology and membrane deformation capacity have different degrees of variation, but the structure of intracellular hemoglobin has not changed, suggesting that the cell morphology and membrane deformation capacity may be reversible. The results suggest that in the suspension solution containing serum albumin, erythrocytes have better ability to regulate and control the variation of the extracellular pH. In summary, upon building an environment which contains the same concentration radio of serum albumin to hemoglobin in the blood, this work performed systematic studies on the effect of pH on human erythrocytes. It can not only help to solve the problems about the mechanism of the structural and functional changes of erythrocytes induced by environmental pH, but also elucidates the possible variation of the erythrocyte under different pathologic states. It is therefore significant for the prevention and treatment of some diseases.