Lipid peroxidation by nitric oxide supplements after spinal cord injury: effect of antioxidants in rats

To determine the extent to which exogenous nitric oxide (NO) might affect hemodynamics and/or increase oxidative damage after acute spinal cord (SC) injury, rats were submitted to SC contusion, and given a NO donor or NO precursor. Intravenous isosorbide dinitrate (10 microg/kg per min) or L-arginine (300 mg/kg per 23 h) showed a tendency to increase lipid peroxidation (LP), although without reaching significance compared to non-treated injured rats 24 h post-injury, and without affecting mean arterial pressure and heart rate importantly. LP due to injury and exogenous NO was significantly inhibited by the co-administration of a cocktail of antioxidants (12 mg/kg superoxide dismutase mimetic, 27000 U/kg catalase, and 12 mg/kg glutathione), but less effectively for the injury-L-arginine condition. These results demonstrate that in order to further test the potential neuroprotective effect of NO enhancing reagents after SC injury, antioxidants must be included in the treatment scheme.