Bowman W C, Harvey A L, Marshall I G
Naunyn Schmiedebergs Arch Pharmacol. 1977 Mar;297(1):99-103. doi: 10.1007/BF00508816.
The effects of 2-, 3-, and 4-aminopyridines were investigated on the isolated chick biventer cervicis nerve-muscle preparation and on nerve-free cell cultures of embryonic chick skeletal muscle. All 3 compounds reversed tubocurarine blockade and augmented twitch height in indirectly stimulated biventer cervicis preparations. 4-Aminopyridine was approximately 10 times more potent than 2-, or 3-aminopyridine. Twitch augmentation was also seen in directly stimulated preparations but to a much lesser extent. The compounds did not have significant anticholinesterase activity, nor did they have any depolarizing activity when tested on nerve-free cultured muscle fibres. At high concentrations the aminopyridines produced a maintained contracture in the biventer preparations which was enhanced by neostigmine and inhibited by tubocurarine. It is suggested that the aminopyridines facilitate neuromuscular transmission by increasing acetylcholine release in response to nerve stimulation, and that the compounds can also increase spontaneous transmitter release.
研究了2-氨基吡啶、3-氨基吡啶和4-氨基吡啶对离体鸡双腹肌神经-肌肉标本以及鸡胚骨骼肌无神经细胞培养物的作用。这3种化合物均可逆转筒箭毒碱的阻滞作用，并增强间接刺激双腹肌标本时的抽搐高度。4-氨基吡啶的效力约为2-氨基吡啶或3-氨基吡啶的10倍。在直接刺激的标本中也可见到抽搐增强，但程度要小得多。这些化合物没有明显的抗胆碱酯酶活性，在无神经的培养肌纤维上进行测试时也没有任何去极化活性。在高浓度时，氨基吡啶在双腹肌标本中产生持续的挛缩，新斯的明可增强这种挛缩，筒箭毒碱可抑制这种挛缩。提示氨基吡啶通过增加神经刺激时乙酰胆碱的释放来促进神经肌肉传递，并且这些化合物还可增加递质的自发释放。
