[The effect of the high-molecular components of the blood serum--gamma-globulin and albumin--on the sodium channel activity of neuroblastoma cells].

Blood serum gamma-globulin and albumin were tested for their effect on the sodium currents of voltage clamped internally perfused serum deprived neuroblastoma cells. Albumin in the concentration corresponding to its content in 5% blood serum (22 microM) produced an increase in sodium channel currents and shifts in activation and inactivation curves along the voltage axis towards more negative or positive potentials, respectively. These results both qualitatively and quantitatively reproduce the effects of 5% blood serum observed previously (Zubov, Sal'nikov, 1984, 1986). The addition of gamma-globulin failed to change the parameters registered. The data obtained led us to an assumption of the role of albumin as an active substance responsible for the effect of blood serum on the potential-dependent sodium-transporting system of neuroblastoma cell membrane.