[The effect of the external electric field on Ca2+ transport in the sarcoplasmic reticulum].
The effect of active and passive Ca2+ transport in sarcoplasmic reticulum vesicles on the rate of negative diffusion potential dissipation was investigated by the method of potential-sensitive fluorescent probes. Membrane potentials were generated by K+ gradients in the presence of valinomycin and were measured using dye diS-C3-(5). It was shown that the rate of K+ potential dissipation was accelerated during Ca2+ transport and depended on ATP and Ca2+ concentrations. In its turn the initial rate of ATP hydrolysis was found to be increased in the presence of negative potential. The obtained results support an electrogenic mechanism for the Ca2+ transport by the sarcoplasmic reticulum.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D005456:Fluorescent Dyes; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials; D009132:Muscles / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*
D005456:Fluorescent Dyes; D007473:Ion Channels; D000255:Adenosine Triphosphate; D011188:Potassium; D002118:Calcium
Vliianie vneshnego élektricheskogo polia na transport Ca2+ v sarkoplazmaticheskom retikulume.