title: Ionic determinants of spontaneous activity in clusters of cultured cardiac cells from newborn rats.
abstract: The spontaneous activity of cell clusters derived from ventricle cells of newborn rats was studied using a recording television microscope. The influence of varying concentrations of sodium, potassium, calcium, tetrodotoxin (TTX), and that of 2 mM MnCl2 was tested. The spontaneous activity of the cell clusters persisted in TTX but it was abolished by Mn. The beating rate increased when [Ca]0 and [Na]0 were changed from 0.3 mM to 3.0 mM and from 30 mM to 75 mM; it decreased with a change of [Na]0 from 75 mM to 142 mM. It is concluded that electrogenesis in their behavior to very young embryonic rat heart cells or cells of the rabbit sinoauricular node.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D006321:Heart / Q000502:physiology; D008345:Manganese / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D011188:Potassium / Q000502:physiology; D051381:Rats; D012964:Sodium / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D008345:Manganese; D013779:Tetrodotoxin; D012964:Sodium; D011188:Potassium; D002118:Calcium