Regulation of cardiac Ca2+ channels by cGMP and NO

摘要: There is ample evidence that cAMP and cGMP lead to opposite contractile electrical responses in the heart [1–11]. Since regulation of L-type calcium channel current (ICa) often correlated with cardiac contraction, it was conceivable both nucleotides exert actions on ICa. The stimulatory effect ICa has been well documented. Cyclic AMP activation cAMP-dependent protein kinase (cAMP-PK) leads phosphorylation Ca2+ channels (or a closely associated protein), resulting an increase mean probability opening stimulation macroscopic [11–13], By symmetry, proposed negative inotropic mediated by decrease Among supporting this hypothesis are findings reduces 45Ca flux [3], shortens action potential duration [14], inhibits -dependent potentials [15–18].