Adenosines scavenged hydroxyl radicals and prevented posttraumatic epilepsy

Free Radic Biol Med. 1995 Oct;19(4):473-9. doi: 10.1016/0891-5849(95)00050-8.

Abstract

Intracortical injection of iron ions has been used as a model of posttraumatic epilepsy. Oxidation of lipids in neural membranes by reactive oxygen species, especially hydroxyl radicals (OH), is involved in the mechanisms responsible for iron-induced seizures. We examined the scavenging effects of adenosine (Ado) and 2-chloroadenosine (Cl-Ado) on OH radicals and superoxide (O2.-) using an electron spin resonance (ESR) spectrometer, and the occurrence of epileptic discharges in electrocorticogram (ECoG) induced by FeCl3 injection into the sensorimotor cortex of rats. Though DMPO-O2.- spin adducts generated by the hypoxanthine-xanthine oxidase system were not quenched by Ado or Cl-Ado, 5 mM of each showed a quenching effect on DMPO-OH spin adducts (5.3 x 10(16) spins/ml) generated by the Fenton reagent. In ECoG of rats, spike discharges appeared 15-45 min after FeCl3 injection (500 nmol) into the sensorimotor cortex, and polyspikes and/or ictal patterns were observed 70-90 min after the injection. Cl-Ado (1 mg/kg) or Ado (5 mg/kg) injected intraperitoneally 30 min prior to the FeCl3 injection suppressed or delayed the occurrence of epileptic discharges induced by FeCl3. Cl-Ado and Ado may suppress the occurrence of epileptic discharges by scavenging OH and by their anticonvulsant effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2-Chloroadenosine / pharmacology
  • 2-Chloroadenosine / therapeutic use*
  • Adenosine / pharmacology
  • Adenosine / therapeutic use*
  • Animals
  • Chlorides
  • Cyclic N-Oxides
  • Electroencephalography
  • Electron Spin Resonance Spectroscopy
  • Epilepsy, Post-Traumatic / chemically induced
  • Epilepsy, Post-Traumatic / prevention & control*
  • Ferric Compounds
  • Free Radical Scavengers*
  • Free Radicals
  • Hydroxyl Radical / metabolism*
  • Hypoxanthine
  • Hypoxanthines / metabolism
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Spin Labels
  • Superoxides / metabolism
  • Xanthine Oxidase / metabolism

Substances

  • Chlorides
  • Cyclic N-Oxides
  • Ferric Compounds
  • Free Radical Scavengers
  • Free Radicals
  • Hypoxanthines
  • Spin Labels
  • Superoxides
  • 2-Chloroadenosine
  • Hypoxanthine
  • Hydroxyl Radical
  • 5,5-dimethyl-1-pyrroline-1-oxide
  • Xanthine Oxidase
  • Adenosine
  • ferric chloride