Mert Tufan, Gunes Yasemin, Guven Mustafa, Gunay Ismail, Gocmen Cemil
Department of Biophysics, University of Cukurova, School of Medicine, Balcali, TR-01330 Adana, Turkey.
Pharmacology. 2003 Oct;69(2):68-73. doi: 10.1159/000072358.
We have used the sucrose gap method to measure the effects of drugs on the electrophysiological properties of rat sciatic nerves. The results showed that 4-aminopyridine produced a slight conduction block, prolonged the duration of action potential, enhanced the hyperpolarizing afterpotential, and elicited a hump that followed the action potential. In the presence of 4-aminopyridine, the impulse-blocking activity of lidocaine and tramadol was enhanced. Both lidocaine and tramadol effectively depressed the delayed depolarization generated by 4-aminopyridine. While tramadol decreased the activity-evoked hyperpolarizing afterpotentials, lidocaine completely removed them. These findings indicate that lidocaine may be more effective in blocking the Na(+) channels than tramadol. Tramadol may be more effective on the delayed rectifier K(+) channels than lidocaine.
我们使用蔗糖间隙法来测量药物对大鼠坐骨神经电生理特性的影响。结果表明，4-氨基吡啶产生轻微的传导阻滞，延长动作电位的持续时间，增强超极化后电位，并引发跟随动作电位的驼峰。在4-氨基吡啶存在的情况下，利多卡因和曲马多的冲动阻断活性增强。利多卡因和曲马多均有效抑制了4-氨基吡啶产生的延迟去极化。虽然曲马多降低了活动诱发的超极化后电位，但利多卡因完全消除了它们。这些发现表明，利多卡因在阻断Na(+)通道方面可能比曲马多更有效。曲马多在延迟整流K(+)通道上可能比利多卡因更有效。
