title: L-arginine modifies free radical production and the development of experimental allergic encephalomyelitis.
abstract: OBJECTIVE
  The present investigation examines the effects of increasing central nervous system (CNS) levels of nitric oxide (NO), via the administration of L-arginine, on the development of experimental allergic encephalomyelitis (EAE).
  
  
  METHODS
  EAE was induced in male Lewis rats (200-250 g).
  
  
  METHODS
  Normal rats were orally dosed with L-arginine (300 mg/kg body weight) once daily for 12 days. EAE-sensitised animals received L-arginine (300 mg/kg body weight) once daily from day 1 to 12 post-inoculation.
  
  
  METHODS
  Neurological and histological development of EAE were assessed. In addition, CNS cytosol levels of nitrite, superoxide and hydrogen peroxide were measured. Results were analysed using the Mann Whitney U-test and Chi-squared test.
  
  
  RESULTS
  L-arginine administration significantly delayed disease onset (p < 0.05) and reduced the severity of neurological (p < 0.05) and histological (p < 0.001) signs of EAE. Treatment with L-arginine caused a significant elevation in CNS nitrite concentrations (p < 0.05) which in EAE-sensitised animals was associated with a concomitant and dramatic decrease in superoxide (p < 0.05) and hydrogen peroxide (p < 0.05) levels.
  
  
  CONCLUSIONS
  The results suggest that NO may act as a protective molecule during the development of EAE possibly via the modulation of oxidant-mediated neuroinflammation.
authors.affiliation: William Harvey Research Institute, Charterhouse Square, University of London, UK.
authors.forename: G S
authors.initials: GS
authors.lastname: Scott
authors.forename: C
authors.initials: C
authors.lastname: Bolton
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002199:Capillary Permeability / Q000187:drug effects; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000473:pathology*; D005609:Free Radicals / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D013481:Superoxides / Q000378:metabolism
chemical_list: D005609:Free Radicals; D013481:Superoxides; D009569:Nitric Oxide; D001120:Arginine; D006861:Hydrogen Peroxide