Osmoregulatory reactions of frog erythrocytes under conditions of activation and blockade of Ca2+-channels

The kinetics of cell osmoregulatory reactions under conditions of activation and blockade of Ca2+-channels was studied on a model of frog polyfunctional nucleated erythrocytes. Both activation and blockade of Ca2+-channels has been established to promote swelling of nuclei and an increase of the nucleocytoplasmic ratios under conditions of hypotonic exposure. The osmoregulatory cell reactions after activation of Ca2+-channels are manifested as a decrease of the cell volume. The blocker of Ca2+-channels verapamil produces a transitory increase and decrease of the erythrocyte volume with time intervals of 30 and 60 s. The clearly expressed functional activity of the nuclear membrane in response to the hypotonic action under conditions of activation and blockade of Ca2+-channels indicates participation of Ca2+ ions in mechanisms of the nucleocytoplasmic transfer.