Roles of nitric oxide in compression injury of rat spinal cord.
Nitric oxide (NO) was measured directly after spinal cord injury (SCI) in rats by an ESR spin-trapping technique using Fe2+ and diethyldithiocarbamate (DETC). The levels of NO and lipid peroxides expressed as thiobarbituric acid reactive substances (TBARS) were increased by SCI in the injured region and the adjacent central region. Pretreatment with 30 mg/kg of NG-nitro-L-arginine methylester (L-NAME), an inhibitor of NO synthase, accelerated increases of the TBARS level and myeloperoxidase (MPO) activity in the injured tissue and caused deterioration of hind limb motor function after SCI, suggesting that NO formation by constitutive NO synthase (c-NOS) has a protective effect against cellular damage resulting from ischemia-reperfusion after SCI. Though c-NOS mRNA expression was not altered after SCI, inducible NO synthase (i-NOS) mRNA expression increased to a maximum of 24 h after SCI with progress of motor dysfunction. Intravenous injection of L-NAME (0.1 mg/kg) 6, 24, 48, and 72 h after SCI reduced the motor disturbance. These results indicate that NO induced by i-NOS may be neurotoxic in the subacute phase after SCI.
Department of Orthopedic Surgery, School of Medicine, The University of Tokushima, Japan.
Y
Y
Hamada
T
T
Ikata
S
S
Katoh
K
K
Tsuchiya
M
M
Niwa
Y
Y
Tsutsumishita
K
K
Fukuzawa
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000235:genetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D009195:Peroxidase / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013117:Spinal Cord Compression / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D017931:DNA Primers; D004791:Enzyme Inhibitors; D008054:Lipid Peroxides; D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; D009195:Peroxidase; D019001:Nitric Oxide Synthase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D019331:NG-Nitroarginine Methyl Ester