title: Isometric dynamic response of mammalian heart muscle due to step changes in the calcium concentration of the perfusing medium.
abstract: The isometric tension transient response of isolated kitten papillary muscle was found to exhibit direction-dependent dynamics when subjected to step changes in the calcium concentration of the bathing medium. The tension transient curves could be resolved into a minimum of two to three exponential components, which could be considered to indicate different calcium compounds or compartments within the muscle. However, a model relating calcium diffusion across the muscle to the dose-response curve indicates that the exponential components of the tension transient curves are due to the properties of calcium diffusion through the extracellular space, and that the direction-dependent dynamics are caused by the nonlinearity of the dose-response curve.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008722:Methods; D008954:Models, Biological; D009200:Myocardial Contraction / Q000187:drug effects*
chemical_list: D002118:Calcium