Effect of Mg2SO4 usage on spinal cord ischemia-reperfusion injury: electron microscopic and functional evaluation

OBJECTIVES: To evaluate the effects of intravenous magnesium sulfate (Mg(2)SO(4)) administration on ischemia-reperfusion injury of the spinal cord. MATERIAL AND METHODS: Sixteen rabbits were randomly assigned to the control (group I, 8 rabbits) and the study group (group II, 8 rabbits). The abdominal aorta was clamped for a period of 30 min followed by a reperfusion period of 60 min. The animals in group II received 0.25 ml/kg/h Mg(2)SO(4) intravenous infusion (15% Mg(2)SO(4)) throughout this procedure. The animals were then observed for 24 h after which their neurological states were evaluated and tissue samples obtained from the spinal cord were examined with electron microscopy. RESULTS: Aortic pressure distal to the cross-clamp during the occlusion period was 9 +/- 3 mm Hg in group I and 19 +/- 6 mm Hg in group II. All animals in group I were paraplegic at the end of the study. In group II the neurological outcome of 1 animal was poor while the other 7 animals were neurologically in a good condition. Electron microscopic examinations of the spinal cord tissues of group I revealed severe injury but the ultrastructure was well preserved in group II. CONCLUSIONS: Intravenous Mg(2)SO(4) administration may have protective effects on the ischemia-reperfusion injury of the spinal cord. We propose that Mg(2)SO(4) may be an additional protective pharmacological agent in thoracal and thoracoabdominal aortic surgery.