[Na-Ca-exchange as a mechanism regulating spontaneous contractions of isolated individual cardiomyocytes].
The frequency (f) of spontaneous contractions (SC) were registered on single enzymatically isolated cardiomyocytes of adult rats using current-carrying electrode through which current (50-200 nA) was passed. Cell motion on the electrode during SC caused current oscillations, measured by an amplifier. The actions of Na+, K+, Ca2+, caffeine, epinephrine and isoptin on fSC have been studied. The data obtained suggest that spontaneous contractions of isolated cardiomyocytes are related to increased intracellular Ca2+ concentration due to Na-Ca exchange. Cyclic contractions can possibly be accounted for by the work of sarcoplasmic reticulum.
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002463:Cell Membrane Permeability; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000502:physiology*
D002110:Caffeine; D012964:Sodium; D002118:Calcium
Na-Ca-obmen kak reguliatornoĭ mekhanizm spontannykh sokrashcheniĭ izolirovannykh odinochnykh kardiomiotsitov.