N,N-diethyldithiocarbamate produces copper accumulation, lipid peroxidation, and myelin injury in rat peripheral nerve

Toxicol Sci. 2004 Sep;81(1):160-71. doi: 10.1093/toxsci/kfh190. Epub 2004 Jun 8.

Abstract

Previous studies have demonstrated the ability of the dithiocarbamate, disulfiram, to produce a peripheral neuropathy in humans and experimental animals and have also provided evidence that N,N-diethyldithiocarbamate (DEDC) is a proximate toxic species of disulfiram. The ability of DEDC to elevate copper levels in the brain suggests that it may also elevate levels of copper in peripheral nerve, possibly leading to oxidative stress and lipid peroxidation from redox cycling of copper. The study presented here investigates the potential of DEDC to promote copper accumulation and lipid peroxidation in peripheral nerve. Rats were administered either DEDC or deionized water by ip osmotic pumps and fed a normal diet or diet containing elevated copper, and the levels of metals, isoprostanes, and the severity of lesions in peripheral nerve and brain were assessed by ICP-AES/AAS, GC/MS, and light microscopy, respectively. Copper was the only metal that demonstrated any significant compound-related elevations relative to controls, and total copper was increased in both brain and peripheral nerve in animals administered DEDC on both diets. In contrast, lesions and elevated F2-isoprostanes were significantly increased only in peripheral nerve for the rats administered DEDC on both diets. Autometallography staining of peripheral nerve was consistent with increased metal content along the myelin sheath, but in brain, focal densities were observed, and a periportal distribution occurred in liver. These data are consistent with the peripheral nervous system being more sensitive to DEDC-mediated demyelination and demonstrate the ability of DEDC to elevate copper levels in peripheral nerve. Additionally lipid peroxidation appears to either be a contributing event in the development of demyelination, possibly through an increase of redox active copper, or a consequence of the myelin injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol Deterrents / toxicity
  • Animals
  • Chelating Agents / toxicity*
  • Chromatography, High Pressure Liquid
  • Copper / metabolism*
  • Diet
  • Disulfiram / toxicity
  • Ditiocarb / toxicity*
  • Gas Chromatography-Mass Spectrometry
  • Histocytochemistry
  • Isoprostanes / metabolism
  • Lipid Peroxidation / drug effects*
  • Liver / pathology
  • Liver Function Tests
  • Male
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / pathology
  • Myelin Sheath / drug effects*
  • Myelin Sheath / pathology
  • Neuromuscular Junction / drug effects
  • Neuromuscular Junction / pathology
  • Peripheral Nerves / drug effects*
  • Peripheral Nerves / metabolism
  • Peripheral Nerves / pathology
  • Rats
  • Rats, Sprague-Dawley
  • Silver Staining
  • Spectrophotometry, Atomic
  • Tissue Distribution
  • Weight Gain / drug effects

Substances

  • Alcohol Deterrents
  • Chelating Agents
  • Isoprostanes
  • Copper
  • Ditiocarb
  • Disulfiram