Figure 4.
Effects of F 15845 on action potentials from rabbit Purkinje fibres and left atria. (A) Experimental action potential recordings of rabbit left atria (elicited at 1 Hz) in the absence and presence of 10 µM F 15845. (B) Experimental action potential recordings from rabbit Purkinje fibres (elicited at 1 Hz) in the absence and presence of various concentrations of F 15845 (0.1 µM; 1 µM and 10 µM). (C) Experimental recordings of veratridine-modified action potential (elicited at 1 Hz) in the absence and presence of 10 µM F 15845. Veratridine was superfused at 0.1 µM to induce the INap exhibited with the apparent increase in the duration of plateau phase. (D) Graphs representing the effects of F 15845 on APD50 (lower graph) and APD90 (upper graph) in left atria, Purkinje fibres from rabbit hearts and in papillary muscles from guinea pig hearts. Data are means ± SEM of absolute variation (ms). ** < 0.01 and ***P < 0.001 vs. baseline. Values of guinea pig papillary muscle were obtained from a previous study.