Prostran M, Varagic V M, Milovanovic S R, Prostran M S, Vasiljevic Z
Institut de Pharmacologie, Faculté de Médecine, Belgrade, Yougoslavie.
C R Seances Soc Biol Fil. 1988;182(6):556-62.
All DHPs (nifedipine, nicardipine, nitrendipine) produced a concentration-dependent depression of the isometric contraction and of the atrial rate of the isolated, spontaneously beating atria of the guinea-pig. The depressive actions of nifedipine and nitrendipine were completely antagonized by the addition of calcium, aminophylline and isoprenaline. Aminophylline partially, calcium almost completely and isoprenaline completely antagonized the depressive action of nicardipine on the isometric contraction. Only isoprenaline antagonized the effect of DHPs on the atrial rate of the isolated, spontaneously beating atria of the guinea-pig. It is possible that all these substances restore the contractibility of the atria by compensating the calcium balance, previously changed by DHPs, or by producing an increase in the intracellular cyclic AMP content (aminophylline and isoprenaline).
所有二氢吡啶类药物（硝苯地平、尼卡地平、尼群地平）均对豚鼠离体自发搏动心房的等长收缩和心房率产生浓度依赖性抑制作用。加入钙、氨茶碱和异丙肾上腺素后，硝苯地平和尼群地平的抑制作用完全被拮抗。氨茶碱部分拮抗、钙几乎完全拮抗、异丙肾上腺素完全拮抗尼卡地平对等长收缩的抑制作用。只有异丙肾上腺素能拮抗二氢吡啶类药物对豚鼠离体自发搏动心房心房率的影响。所有这些物质有可能通过补偿先前被二氢吡啶类药物改变的钙平衡，或通过增加细胞内环磷酸腺苷含量（氨茶碱和异丙肾上腺素）来恢复心房的收缩能力。
