Küçükali Cem İsmail, Tüzün Erdem, Nurten Asiye
Department of Neuroscience, İstanbul University, Institution of Experimental Medicine, İstanbul, Turkey.
Department of Physiology, Yeni Yüzyıl University School of Medicine, İstanbul, Turkey.
Noro Psikiyatr Ars. 2017 Sep;54(3):202-204. doi: 10.5152/npa.2017.19422. Epub 2016 Sep 1.
Topiramate has a negative modulatory effect on voltage-gated ion channels involved in neuromuscular junction transmission. To investigate the potential impact of topiramate on muscle contraction, phrenic nerve-hemidiaphragm preparations were used as a neuromuscular junction model.
Phrenic nerve-hemidiaphragm preparations were isolated from rats and were mounted in oxygenated Krebs solution. Preparations were stimulated in the presence of topiramate and phenytoin with a rectangular pulse at 0.1 Hertz, 0.3 miliseconds, and 3 miliseconds of duration, forming indirect, direct single, and tetanic muscle contractions, respectively. The expressed tension was isometrically recorded via a force displacement transducer on a polygraph.
Topiramate and phenytoin directly and indirectly reduced contractions in a time-dependent manner. By contrast, topiramate, but not phenytoin, showed an excitatory effect on contraction in tetanic potentiation.
To our knowledge, our study is the first to show the effects of topiramate on muscle contraction and neuromuscular junction transmission. Topiramate needs to be used with caution in patients with muscle weakness and respiratory problems.
托吡酯对参与神经肌肉接头传递的电压门控离子通道具有负性调节作用。为研究托吡酯对肌肉收缩的潜在影响，采用膈神经 - 半膈肌标本作为神经肌肉接头模型。
从大鼠分离出膈神经 - 半膈肌标本，并置于含氧的 Krebs 溶液中。在托吡酯和苯妥英存在的情况下，分别用频率为 0.1 赫兹、持续时间为 0.3 毫秒和 3 毫秒的矩形脉冲刺激标本，分别形成间接、直接单次和强直肌肉收缩。通过多道生理记录仪上的力位移传感器等长记录所表达的张力。
托吡酯和苯妥英直接和间接以时间依赖性方式减少收缩。相比之下，托吡酯而非苯妥英在强直增强中对收缩表现出兴奋作用。
据我们所知，我们的研究首次表明托吡酯对肌肉收缩和神经肌肉接头传递的影响。对于肌肉无力和呼吸问题患者，使用托吡酯时需谨慎。
