Changes of free iron contents and its correlation with lipid peroxidation after experimental spinal cord injury

Objective: To observe the dynamic changes of fre e iron contents and its relationship to the changes of lipid peroxidation after experimental spinal cord injury (SCI). Methods: Sprague Dawley rats were randomly divided into three g roups: Group A (n=6) received no operation; Group B (n=48) received only laminec tomy (sham); and Group C (n=48) received both laminectomy and traumatic injury ( SCI model). The SCI animal models were made by using an modified Allens weight -drop device (50 g.cm) on T_ 12 . Rats were sacrificed at 0.5 ,1,3,6,12,24 hours after injury. The levels of free iron involved in spinal cord segm ents at different time points were measured by bleomycin assay. The malondialdeh yde (MDA) was also measured by the thiobarbituric acid (TBA). Results: After SCI in Group C,the level of free iron showed a significant increase at 0.5 hour compared to Groups B and A,restored to th e control level at 6 h; the level of MDA was increased at 0.5 hour,peaked a t 3 hours,returned to the control level at 12 hours; the concentrations of free iron and lipid peroxidation in injured rats were significantly and positively c orrelated at 0.5 -3 hours. Conclusions: After SCI the levels of free iron are increased qu ickly and might be a major contributor to lipid peroxidation in injured spinal c ord.