尼卡地平在异丙肾上腺素扩张气管中的作用

Effect of nicardipine in the isoprenaline-induced relaxation on isolated guinea pig trachea

目的:探讨尼卡地平(Nic)对异丙肾上腺素(Iso)舒张气管的增强作用.方法:在豚鼠离体气管上观察Nic对Iso的增强作用,并与Nic对茶碱(Theo)和硝普钠(SNP)的作用进行比较.结果;(1)Nic能增强Iso豚鼠离体气管的舒张作用.此增强作用具剂量依赖性.表现在Iso量-效曲线随Nic剂量增高而逐渐左移;(2)Theo浓度大于Nic1000倍时,也增强Iso的作用;(3)相同条件下,SNP合用Nic或Theo后对SNP引起的气管舒张无增强作用.结论:Nic和Theo一样,可能通过抑制磷酸二酯酶而增高Iso对气管平滑肌的舒张作用.

AIM:To study the effect of nicardipine (Nic)in the isoprenaline (Iso)-induced relaxation on the guinea pig airway. METHODS :The potential effect of calcium antagonist Nic was studied with 2 different relaxant compounds on isolated airway strips. RESULTS: (l)the relaxation of Iso was concentration-dependently potented with using calcium antagonist Nic; (2)theophylIine(Theo),a specific phosphodiesterase antagonist,also potented the relaxant effect of Iso;(3)under similar condition,Nic or Theo did not influence the relaxant effect induced by sodium nitroprusside (SNP). CONCLUSION:Nic behaves as an inhibitor of phosphodiesterases IV and IV. One such effect may be involved in the potentiation of the Iso relaxation of isolated guinea pig airways.