间硝苯啶对兔和肾型高血压大鼠肺动脉的钙拮抗作用

间硝苯啶（ｍ－Ｎｉｆ）和硝苯啶（Ｎｉｆ）对氯化钙所致正常家兔肺动脉环呈非竞争拮抗作用，ＰＤ＇２分别为６．１４和５．９８。松弛兔肺动脉环收缩的ＩＣ５０分别为０．９３μｍｏｌ·Ｌ－１和１．１３μｍｏｌ·Ｌ－１。肾型高血压大鼠肺动脉和主动脉对氯化钾的收缩反应明显增高（Ｐ＜０．０１），ｍ－Ｎｉｆ和Ｎｉｆ松弛未经治疗高血压大鼠肺动脉和主动脉的ＩＣ５０明显低于正常大鼠，而松弛经治疗高血压大鼠肺动脉和主动脉的ＩＣ５０与正常大鼠比较无差异。提示：ｍ－Ｎｉｆ与Ｎｉｆ作用相似，ｍ－Ｎｉｆ和Ｎｉｆ对未经治疗高血压大鼠肺动脉和主动脉的松弛作用明显增大，而对经治疗高血压大鼠肺动脉和主动脉的松弛作用接近正常。

Calcium-antagonistic effects of m-nifdipine on isolated pulmonary artery of rabbits and renovascular hypertensive rats

In isolated rabbit pulmonary artery mnifidiPine(m-Nif) and nifidiPine(Nif) inhibited the contraction induced by calcium and shifted the concentration-response curve nonparallely to right.The values of PD'2 are 6.14 and 5.89,IC50 values are 0.93 μmol·L-1 and 1.13 μmol·L11 respectively.In isolated rat pulmonary artery and aorta,the respones of pulmonary artery and aorta to KCl are higher in hypertension than in normotension(P<0.01).m-Nif and Nif inhibited pulmonary artery and aorta,IC50 values are lower in hypertensive rats than in normal rats.There is no evident difference between IC50values in treated-hypertensive rats and those in normal rats.These results indicate that the action of mNif is simlar to that of Nif,the relaxant responses of pulmonary artery and aorta to m-Nif and Nif increase,after treated with m-Nif or Nif,the relaxant responses of pulmonary artery and aorta to m-Nif and Nif are restored and near to those of normal rats.