Table 1. Effects of nifedipine on systolic tension, coronary flow and maximal (+dT/dt) and minimal (-dT/dt) contractility of isolated rat hearts from Wistar audiogenic rats and Wistar rats.

	WAR	WAR + N20	WAR + N40	Wistar	Wistar + N20	Wistar + N40
ST	10.0 ± 0.6	9.7 ± 1.1	8.5 ± 0.8	9.5 ± 0.6	9.1 ± 0.6	8.8 ± 0.9
CF	7.89 ± 0.9	7.96 ± 0.5	7.11 ± 1.0	8.64 ± 0.8	8.50 ± 0.5	8.21 ± 0.6
+dT/dt	211 ± 15	196 ± 22	212 ± 19	192 ± 18	182 ± 12	173 ± 10
-dT/dt	231 ± 18	244 ± 24	204 ± 18	205 ± 16	202 ± 20	197 ± 7

Data are reported as means ± SEM for 6 rats per group. No significant differences were observed among any of the groups. N20 and N40 = 20 and 40 mg/kg nifedipine, respectively; ST = systolic tension (g); CF = coronary flow (mL/min); WAR = Wistar audiogenic rats.