Angiotensin II stimulates cardiac L-type Ca2+ current by a Ca2+- and protein kinase C-dependent mechanism

Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata 1900, Argentina Angiotensin II (ANG II) evokes positive inotropic responses in various species. However, the effects of this peptide on L-type Ca 2+ currents ( I Ca ) are still controversial. We report in this study that the effects of ANG II on I Ca differ depending on the mode of patch-clamp technique used, standard whole cell (WC) or perforated patch (PP). No significant effects of ANG II (0.5 µM) were observed when WC in cells dialyzed with high EGTA was used. However, when the intracellular milieu was preserved using PP, ANG II induced a significant 77 ± 6% increase in I Ca ( 2.2 ± 0.3 in control and 3.9 ± 0.6 pA/pF in ANG II, n = 8, P