摘要
In our experiment it was found that,in guinea pig papillary muscles,8205 de-creased the automaticity and prolonged the functional refractory period（FRP）as well asdecreased the contractile amplitude dose-dependently,but exerted no effect on the excitabili-ty.The dose-response curves of isoproterenol shifted to the right in parallel manner,inaccordance with competitive antagonistic,but the effect of 8205 was much less than thatof propranolol.Dose-response curves of CaCl<sub>2</sub> shifted to the right non-parallelly.The re-sults indicated that the mechanism of anti-arrhythmia of 8205 might be related to theCa<sup>2+</sup>-antagonism.
In our experiment it was found that,in guinea pig papillary muscles,8205 de- creased the automaticity and prolonged the functional refractory period(FRP)as well as decreased the contractile amplitude dose-dependently,but exerted no effect on the excitabili- ty.The dose-response curves of isoproterenol shifted to the right in parallel manner,in accordance with competitive antagonistic,but the effect of 8205 was much less than that of propranolol.Dose-response curves of CaCl_2 shifted to the right non-parallelly.The re- sults indicated that the mechanism of anti-arrhythmia of 8205 might be related to the Ca^(2+)-antagonism.
