Mechanism of impaired rheology of aged erythrocytes in relation to the determinants of life span

人红细胞在血流中的寿命主要取决于其通过脾脏的易滤性和粘附性，从而取决于细胞的变形性。目前的研究涉及体内老化红细胞的变形能力。1.开发了一种新的灵敏的方法，用于检测细胞变形能力的细微下降，它测量振荡剪切流中的变形响应。老化红细胞的频率响应在约40 Hz时开始下降。25 ℃时，2 Hz的频率下，年轻红细胞的红其主要原因可能是细胞内粘度增加.长期以来，人们一直认为衰老红细胞能量代谢的降低通过细胞骨架结构的动力学变化引起变形能力的降低，但没有定量研究。本实验表明，衰老红细胞中腺苷酸、ATP和2，3-DPG的减少并不影响细胞的变形能力。相反，人为增加2，3-DPG可能是由于细胞内粘度增加而损害了变形能力。

The life span of human erythrocytes in blood stream depends mainly on the easiness of their filtrability through spleen and on the adhesivity, thus on the cellular deformability. The present studies concerns with the deformability of the in vivo-aged erythrocytes.1. A novel sensitive method for detecting a subtle decrease in cellular deformability is developed, which measures the deformation response in oscillatory shear flow. The frequency response of the aged erythrocytes begins to decrease at ca. 2 Hz at 25 C, while that of young erythrocytes does not at above 3 Hz. The main cause is suggested to be due to the increased intracellular viscosity.2. The decreased energy metabolism in aged erythrocytes has long been said to cause the decrease of the deformability through some change in the dynamics of cytoskeletal structure, without quantitative studies. The present experiments show that the decrease of adenylates, ATP and 2, 3-DPG found in the aged erythrocytes does not affect the cellular deformability. On contrary, the artificially increased 2, 3-DPG impairs the deformability perhaps due to the increased intracellular viscosity.