Schramm M, Thomas G, Towart R, Franckowiak G
Arzneimittelforschung. 1983;33(9):1268-72.
The effects of the novel, 1,4-dihydropyridine derivative methyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl) -pyridine-5-carboxylate (Bay k 8644) are reported. In contrast to the nifedipine-like dihydropyridines, which have calcium antagonistic actions. Bay k 8644 has positive inotropic and vasoconstrictor effects. The effects and mechanism of action of Bay k 8644 have been examined in the anaesthetised dog, on the isolated perfused guinea-pig heart, and on the isolated rabbit aortic strip. In these preparations Bay k 8644 is active in the same dose range as nifedipine, but has effects diametrically opposite to those of nifedipine. There is a competitive antagonism between Bay k 8644 and nifedipine, whereas verapamil and diltiazem produce only a functional, non-competitive inhibition of the effects of Bay k 8644. We conclude that a specific dihydropyridine receptor exists, which may bind both nifedipine and Bay k 8644. In contrast to nifedipine Bay k 8644 stimulates the calcium influx into the cell.
本文报道了新型1,4 - 二氢吡啶衍生物1,4 - 二氢 - 2,6 - 二甲基 - 3 - 硝基 - 4 -（2 - 三氟甲基苯基）吡啶 - 5 - 羧酸甲酯（Bay k 8644）的作用。与具有钙拮抗作用的硝苯地平类二氢吡啶不同，Bay k 8644具有正性肌力作用和血管收缩作用。已在麻醉犬、离体灌注豚鼠心脏以及离体兔主动脉条上研究了Bay k 8644的作用及作用机制。在这些实验制剂中，Bay k 8644与硝苯地平在相同剂量范围内均有活性，但作用却截然相反。Bay k 8644与硝苯地平之间存在竞争性拮抗作用，而维拉帕米和地尔硫䓬仅对Bay k 8644的作用产生功能性非竞争性抑制。我们得出结论，存在一种特异性二氢吡啶受体，它可能同时结合硝苯地平和Bay k 8644。与硝苯地平相反，Bay k 8644刺激钙流入细胞。
