Ca2+ currents in cardiac myocytes: Old story, new insights.
Calcium is a ubiquitous second messenger which plays key roles in numerous physiological functions. In cardiac myocytes, Ca2+ crosses the plasma membrane via specialized voltage-gated Ca2+ channels which have two main functions: (i) carrying depolarizing current by allowing positively charged Ca2+ ions to move into the cell; (ii) triggering Ca2+ release from the sarcoplasmic reticulum. Recently, it has been suggested than Ca2+ channels also participate in excitation-transcription coupling. The purpose of this review is to discuss the physiological roles of Ca2+ currents in cardiac myocytes. Next, we describe local regulation of Ca2+ channels by cyclic nucleotides. We also provide an overview of recent studies investigating the structure-function relationship of Ca2+ channels in cardiac myocytes using heterologous system expression and transgenic mice, with descriptions of the recently discovered Ca2+ channels alpha(1D) and alpha(1E). We finally discuss the potential involvement of Ca2+ currents in cardiac pathologies, such as diseases with autoimmune components, and cardiac remodeling.
Brette
Fabien
F
School of Biomedical Sciences, University of Leeds, Worsley Building Leeds, LS2 9NQ, UK. f.brette@bristol.ac.uk
Leroy
Jérôme
J
Le Guennec
Jean-Yves
JY
Sallé
Laurent
L
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*
D015220:Calcium Channels; D002118:Calcium