Ivanov Ivan Tanev
Department of Physics and Biophysics, Stara Zagora Medical Faculty, Thracian University, Stara Zagora 6000, Bulgaria.
Comp Biochem Physiol A Mol Integr Physiol. 2007 Aug;147(4):876-84. doi: 10.1016/j.cbpa.2007.02.016. Epub 2007 Feb 21.
Thermal stability of erythrocyte membrane is a measure for its ability to maintain permeability barrier at deleterious conditions. Hence, it could impact the resistance of erythrocytes against detrimental factors in circulation. In this study the thermostability of erythrocyte membranes was expressed by the temperature, T(go), at which the transmembrane gradient of ion concentration rapidly dissipated during transient heating. T(go) is the inducing temperature of the membrane transition that activated passive ion permeability at hyperthermia causing thermal hemolysis. A good allometric correlation of T(go) to the resistance against thermal hemolysis and the life span of erythrocytes were found for 13 mammals; sheep, cow, goat, dog, horse, man, rabbit, pig, cat, hamster, guinea pig, rat, and mouse. For the same group, the values of T(go) were strictly related to the sphingomyelin content of erythrocyte membranes. The residual ion permeability, P, was temperature activated from 38 to 57 degrees C with activation energy of 250+/-15 kJ/mol that strongly differed from that below 37 degrees C. The projected value of P at 37 degrees C was about half that of residual physiological permeability for Na+ and K+ that build ground for possible explanation of the life span vs membrane thermostability allometric correlation.
红细胞膜的热稳定性是衡量其在有害条件下维持通透性屏障能力的指标。因此，它可能会影响红细胞对循环中有害因素的抵抗力。在本研究中，红细胞膜的热稳定性通过温度T（go）来表示，即在短暂加热期间离子浓度跨膜梯度迅速消散时的温度。T（go）是膜转变的诱导温度，在热疗时激活被动离子通透性，导致热溶血。在13种哺乳动物（绵羊、牛、山羊、狗、马、人、兔子、猪、猫、仓鼠、豚鼠、大鼠和小鼠）中发现T（go）与抗热溶血能力和红细胞寿命之间存在良好的异速生长相关性。对于同一组动物，T（go）的值与红细胞膜的鞘磷脂含量密切相关。残余离子通透性P在38至57摄氏度之间被温度激活，激活能为250±15 kJ/mol，这与低于37摄氏度时的激活能有很大差异。37摄氏度时P的预测值约为Na+和K+残余生理通透性的一半，这为解释寿命与膜热稳定性的异速生长相关性提供了可能的依据。
