[Effects of sevoflurane on contraction, membrane ionic currents and intracellular cyclic AMP concentration in canine single ventricular cells].

: The effects of sevoflurane (SV) on contraction, membrane ionic currents and intracellular cAMP concentration were studied in single canine ventricular cells. The authors demonstrated first that SV depressed contractile response of single ventricular cells in a dose-dependent manner. In electrophysiological studies, SV depressed the plateau height and duration of action potentials. Whole-cell voltage clamp experiments revealed that SV depressed voltage-dependent Ca2+ currents in a dose-dependent manner but SV (1%, 2%) did not change Na+ currents. Further, SV (1%, 2%) did not reduce intracellular cAMP concentrations. We conclude that the decrease of myocardial contractile response in single canine cardiac cells by SV is mainly due to the inhibition of voltage-dependent L-type of Ca2+ channels at the sarcolemma and not through changes in intracellular cAMP levels.