Concentration-dependent neurotoxicity of articaine: an electrophysiological and stereological study of the rat sciatic nerve

Anesth Analg. 2011 Jun;112(6):1330-8. doi: 10.1213/ANE.0b013e3182172a2e. Epub 2011 Apr 5.

Abstract

Background: We performed this study to quantify the detrimental effect of intraneural injection of 50 μL of saline, articaine 2%, or articaine 4% in the rat sciatic nerve.

Methods: Lumbar-evoked electrospinograms from stimulation of the sciatic nerve were recorded before and immediately after injection and again after 3 weeks. Test substance was injected into the right sciatic nerve, and the untreated left sciatic nerve served as control. The animals were killed after the 3-week follow-up, and cross-sections of the sciatic nerve were examined stereologically.

Results: The evoked spinal cord field potential in the articaine groups faded away immediately after injection and was concentration-dependently, significantly more reduced at the 3-week follow-up in comparison with the saline group. The response from the control sides was unaffected in all groups. The number of myelinated axons was unaffected by the treatment. The mean cross-sectional axon area and the mean myelin sheath thickness were significantly reduced in animals injected with articaine 4%.

Conclusions: These observations indicate concentration-dependent neurotoxic injuries after injection of articaine with a significant difference between 2% and 4% formulations. The mechanical injury of needle penetration with saline injection had no significant effect on nerve conduction or histomorphology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / metabolism
  • Carticaine / pharmacology*
  • Dose-Response Relationship, Drug
  • Electrophysiology / methods*
  • Female
  • Lumbar Vertebrae / pathology
  • Models, Statistical
  • Myelin Sheath / chemistry
  • Neural Conduction
  • Rats
  • Rats, Wistar
  • Sciatic Nerve / drug effects
  • Sciatic Nerve / pathology*
  • Time Factors

Substances

  • Carticaine