[Lack of low-threshold calcium channels in the membrane of cultured cells of the heart ventricle of newborn rats].
In isolated, cultured neonatal rat ventricular myocytes calcium current was investigated by whole-cell patch clamp technique. The shift of holding potential values from -100-80 mV to -40 mV caused no significant changes in calcium current potential-dependent and kinetic properties. No calcium current component with preferential steady-state inactivation at membrane potentials ranged between -100 and -60 mV was observed. Calcium current component resistant to classic Ca-antagonists action was not found either. All data listed above permit a conclusion on lack of the low-threshold calcium channels in the membrane of single cultured neonatal rat ventricular myocytes. Possible reasons of the absence of this type of calcium are discussed.
Verkhratskiĭ
A N
AN
Pronchuk
N F
NF
Savchenko
A N
AN
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology*; D001693:Biological Transport, Active / Q000502:physiology; D002118:Calcium / Q000493:pharmacokinetics*; D015220:Calcium Channels / Q000502:physiology / Q000648:ultrastructure*; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D006352:Heart Ventricles; D066298:In Vitro Techniques; D009206:Myocardium / Q000648:ultrastructure*; D051381:Rats
D015220:Calcium Channels; D002118:Calcium
Otsutstvie nizkoporogovykh kal'tsievykh kanalov b membrane kul'tiviruemykh kletok zheludochka serdtsa novorozhdennykh krys.