Zubov A N, Pisareva L N, Salnikov K V
Institute of Cytology, Academy of Sciences of the USSR, Leningrad.
Gen Physiol Biophys. 1991 Aug;10(4):321-32.
Blood plasma, serum and its fractions containing components of different molecular weights as well as some identified serum constituents were tested for their action on sodium currents of voltage-clamped, internally dialyzed neuroblastoma cells. Only components with a molecular weight over 50 kDa produced a persistent increase in sodium channel currents (stimulatory effect) and shifts in activation and inactivation curves along the voltage axis towards more negative or positive potentials, respectively (modifying effect). Both modulations taken together provide a somewhat higher level of sodium electro-excitable system activity. Among the identified serum components tested, including those possessing high physiological activity, albumin was the only one which reproduced the effects of whole blood serum both qualitatively and quantitatively. The data obtained allow to assume albumin to play a role of an active substance responsible for the blood plasma or serum effects on the potential-dependent transporting system in the neuroblastoma cell membrane. Albumin seems to be involved in holding the functional activity of sodium channels on a suitable level rather than being involved in any regulatory processes.
对含有不同分子量成分的血浆、血清及其组分以及一些已鉴定的血清成分，测试了它们对电压钳制、内部透析的神经母细胞瘤细胞钠电流的作用。只有分子量超过50 kDa的成分能使钠通道电流持续增加（刺激作用），并使激活曲线和失活曲线分别沿电压轴朝着更负或更正的电位移动（调节作用）。这两种调节作用共同作用，使钠电兴奋系统的活性水平有所提高。在所测试的已鉴定血清成分中，包括那些具有高生理活性的成分，白蛋白是唯一一种在质量和数量上都能重现全血清作用的成分。所获得的数据表明，白蛋白可能是一种活性物质，负责血浆或血清对神经母细胞瘤细胞膜上电位依赖性转运系统的作用。白蛋白似乎是将钠通道的功能活性维持在适当水平，而不是参与任何调节过程。
