Romá J, Cuervo A M, Macian F, Raya A, Gallego J, Llopis J E, Romero F J
Department de Fisiologia, Facultat de Medicina i Odontologia, Universitat de València, Spain.
Neurotoxicol Teratol. 1990 Nov-Dec;12(6):627-31. doi: 10.1016/0892-0362(90)90075-n.
We studied the acute effects of a single dose of phenytoin (250 mg/kg) on peripheral neuromuscular function. The evoked muscle action potentials of the dorsal segmental muscles in the rat tail, and the conduction velocity of the dorsal nerve trunk which innervates them, were measured before and after the intraperitoneal injection of phenytoin. The experiments were performed at different temperatures, 27 (physiological tail temperature), 36 and 37 degrees C (physiological central temperature) in different groups of animals. The amplitudes of the evoked muscle action potentials in the treated groups showed no significant modifications at 27 degrees C, at 36 degrees C a small nonsignificant decrease could be observed, and a complete block occurred at 37 degrees C. The mean blocking time was approximately one hour. No significant variations of conduction velocity were observed at 27 and 36 degrees C, whereas it decreased significantly after 30 minutes at 37 degrees C. The results presented confirm phenytoin toxicity. How far these results, especially the decrease of nerve conduction velocity observed at 37 degrees C, confirm a previous hypothesis which supported that peripheral and central nervous system are affected by phenytoin by similar mechanisms, is discussed.
我们研究了单剂量苯妥英钠（250毫克/千克）对周围神经肌肉功能的急性影响。在腹腔注射苯妥英钠前后，测量大鼠尾巴背段肌肉的诱发肌肉动作电位以及支配这些肌肉的背神经干的传导速度。在不同温度下（27℃，生理尾巴温度；36℃和37℃，生理中心温度），对不同组动物进行实验。在27℃时，治疗组诱发肌肉动作电位的幅度无显著变化；在36℃时，可观察到轻微的非显著性降低；在37℃时则完全阻断。平均阻断时间约为1小时。在27℃和36℃时，传导速度无显著变化，而在37℃时，30分钟后传导速度显著下降。呈现的结果证实了苯妥英钠的毒性。讨论了这些结果，尤其是在37℃观察到的神经传导速度下降，在多大程度上证实了先前支持周围和中枢神经系统受苯妥英钠影响机制相似的假设。
