title: The effect of the reciprocal relationship of Ca2+ and cAMP on the control of beating in cultured rat heart cells.
abstract: The demonstration of Ca2+ control of the cAMP level in heart cells and the localization of the Ca2+ activator protein of cAMP phosphodiesterase on the sarcoplasmic reticulum (SR) have led us to postulate a model whereby the Ca2+ flux is related to the cAMP flux. The model suggests that the increase in cytosol Ca2+ automatically results in an increase in SR Ca2+ and a subsequent decrease in cAMP to allow for the periodic flux of Ca2+ and cAMP in the contraction cycle.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D046508:Culture Techniques; D000242:Cyclic AMP / Q000378:metabolism*; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008954:Models, Biological; D009124:Muscle Proteins / Q000378:metabolism; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
chemical_list: D009124:Muscle Proteins; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002118:Calcium