Wu X D, Rao M R
Zhongguo Yao Li Xue Bao. 1989 Jan;10(1):58-61.
m-Nifedipine (m-Nif) had weaker inhibitory effects than nifedipine (Nif) on the staircase phenomenon, functional refractory period and contraction (IC50: m-Nif/Nif = 18) of isolated guinea pig left atria at concentrations of 0.1-1.0 mumol/L. At the same concentrations, both m-Nif and Nif could hardly change the post-rest potentiation, excitability and ectopic automaticity induced by epinephrine. m-Nif 0.05 mumol/L, had no effect on the automatic contractile force of isolated right atria but could slow down the automatic rhythm. On the contrary, Nif had little effect on the automatic rhythm but potently inhibited the contractile force. Furthermore, in isolated rabbit aorta strips, m-Nif had an equal or somewhat stronger inhibitory effect on the tension induced by KCl. These results suggest that m-Nif might be superior to Nif in treating myocardial ischemia, arterial hypertension and congestive heart failure.
在0.1 - 1.0μmol/L浓度下，间硝苯地平（m-Nif）对豚鼠离体左心房的阶梯现象、功能性不应期和收缩（IC50：m-Nif/Nif = 18）的抑制作用比硝苯地平（Nif）弱。在相同浓度下，m-Nif和Nif几乎都不能改变肾上腺素诱导的复极化后增强、兴奋性和异位自律性。0.05μmol/L的m-Nif对离体右心房的自动收缩力没有影响，但能减慢自动节律。相反，Nif对自动节律影响很小，但能有效抑制收缩力。此外，在离体兔主动脉条中，m-Nif对氯化钾诱导的张力具有同等或稍强的抑制作用。这些结果表明，m-Nif在治疗心肌缺血、动脉高血压和充血性心力衰竭方面可能优于Nif。
