[Divalent cations and nifedipine action on Ca(2+) transport into myometrial plasmalemma vesicles].

While using 45Ca2+ on the model of "outside-out configuration" vesicules of the myometrium cells sarcolemma an investigation of Cd2+, Zn2+, Co2+ and niphedipin on Ca2+ transport into the vesicules in the conditions of protons gradient transmembrane dissipation has been conducted. The above listed substances blocking effect corresponds to their physicochemical properties. Cadmium and zinc ions are considerably more effective in suppressing Ca2+ transport into the vesicules under the dissipation of delta pH on the membrane if compare with the case of delta pH = 0. In the case of niphedipin inhibiting action an opposite result is observed. The hypothesis has been made, that dissipation of delta pH on the sarcolemma is capable to strengthen the transmembrane Ca2+ transport by means of changing the channel structures conformation.