title: Local Ca(2+) signaling and EC coupling in heart: Ca(2+) sparks and the regulation of the [Ca(2+)](i) transient.
abstract: The elementary event of Ca(2+) release in heart is the Ca(2+) spark. It occurs at a low rate during diastole, activated only by the low cytosolic [Ca(2+)](i). Synchronized activation of many sparks is due to the high local [Ca(2+)](i) in the region surrounding the sarcoplasmic reticulum (SR) Ca(2+) release channels and is responsible for the systolic [Ca(2+)](i) transient. The biophysical basis of this calcium signaling is discussed. Attention is placed on the local organization of the ryanodine receptors (SR Ca(2+) release channels, RyRs) and the other proteins that underlie and modulate excitation-contraction (EC) coupling. A brief review of specific elements that regulate SR Ca(2+) release (including SR lumenal Ca(2+) and coupled gating of RyRs) is presented. Finally integrative calcium signaling in heart is presented in the context of normal heart function and heart failure.
authors.affiliation: Medical Biotechnology Center and Institute of Molecular Cardiology, University of Maryland Biotechnology Institute, 725 W. Lombard Street, Baltimore, MD 21201, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Guatimosim
authors.forename: Keith
authors.initials: K
authors.lastname: Dilly
authors.forename: L Fernando
authors.initials: LF
authors.lastname: Santana
authors.forename: M
authors.initials: M
authors.lastname: Saleet Jafri
authors.forename: Eric A
authors.initials: EA
authors.lastname: Sobie
authors.forename: W J
authors.initials: WJ
authors.lastname: Lederer
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D006168:Guinea Pigs; D006333:Heart Failure / Q000209:etiology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D051381:Rats; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism
chemical_list: D020746:Calcium Channels, L-Type; D019837:Ryanodine Receptor Calcium Release Channel; D002118:Calcium