Regulation of L-type calcium current by protein kinases and other signaling molecules in cardiac myocytes

The objective of study was to investigate the role of protein kinase A, protein kinase C, Src family nonreceptor protein tyrosine kinases and other signaling molecules involved in pathways regulating the L-type calcium current (ICa,L) in enzymatically isolated cardiac myocytes. This objective was realized by resolving four tasks: 1) Examination of the basal activity of β-adrenergic receptor (β-AR) signaling cascade involving β-ARs, adenylyl cyclases, phosphodiesterases, protein kinase A, protein phosphatases (protein phosphatase 1 and protein phosphatase 2A) and L-type voltage-dependent calcium channels in frog and rat ventricular myocytes and human atrial myocytes; 2) Investigation of the role of β3-ARs in regulation of ICa,L and force of contraction in human atrium; 3) Exploration of the role of Src family nonreceptor tyrosine kinases in regulation of ICa,L, determining the route of their activation and site of action in β-AR signaling cascade of human atriual myocytes; 4) Probing of the impact of protein kinase C on basal and β-AR stimulated ICa,L in human atrial myocytes. The experiments were performed using whole-cell configuration of the pach-clamp technique