The Effects of Melatonin on the Antioxidant Systems in Experimental Spinal Injury

Melatonin has been recently shown by various in-vivo and in-vitro studies to exert potent neutralising effects on hydroxyl radicals, stimulate glutathione peroxidase (GSH-Px) activity, and protect catalase (CAT) from the destructive activity of hydroxyl radicals in neural tissue. We aimed to investigate the possible effects of pharmacological dose of melatonin on some of the antioxidant defence systems in an in-vivo study of experimental spinal injury. Seven groups of adult male Sprague Dawley rats were used in the following scheme: Group I: Naive (n = 6), Group II: Lesion (n = 8), Group III: Melatonin (n = 5), Group IV: Melatonin + Lesion (n = 8), Group V: Placebo + Lesion (n = 5), Group VI: Sham operation (n = 5), and Group VII: Placebo (n = 5). Experimental spinal injury was induced at level T7-T8 by 5 sec compression of the total cord with an aneurism clip on anaesthetised and laminectomized animals. The total 10mg/kg dose of melatonin (Sigma) dissolved in alcohol-water was administered i.p. four time...