Differential effects of lidocaine and tramadol on modified nerve impulse by 4-aminopyridine in rats

Mert T., Gunes Y., Guven M. , Gunay I. , Gocmen C.

PHARMACOLOGY, vol.69, no.2, pp.68-73, 2003 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 69 Issue: 2
  • Publication Date: 2003
  • Doi Number: 10.1159/000072358
  • Title of Journal : PHARMACOLOGY
  • Page Numbers: pp.68-73


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 after potentials, 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. Copyright (C) 2003 S. Karger AG, Basel.