Effect of carbon monoxide on lipid peroxidation and activities of Na+-K+ ATPase in focal ischemic brain tissue and the neuronal expression of heme oxygenase protein in rats

Objective To study the effect of carbon monoxide (CO) on lipid peroxidation and activities of Na+-K+ ATPase of local cerebral ischemia and the expression of heme oxygenase protein dur-ing early focal ischemia in rats. Methods SD rats were divided into three groups randomly,including he-min group,ZnPP group and saline group. Twelve h before,and 24 h after infarction,the concentrations of CO and MDA, and activities of SOD and Na+-K+ ATPase were examined. The expression of heine oxygen-ase-1(HO-1) protein in the brain of rats during early focal cerebral ischemia was detected by using im-munohistochemistry and computer image analysis in middle cerebral artery occlusion (MCAO) model of rats. Results Compared with the saline group, the concentration of CO in blood was significantly in-creased by 1.36-fold in Heroin group (P<0.01), and that was significantly decreased by 26.4 % in ZnPP group (P<0.01). In Hemin group, MDA was decreased by 11.3% (P<0.01) and the activities of SOD and Na+-K+ ATPase were increased by 6.85% and 20.1% respectively (all P<0.05) as compared with saline group. In ZnPP group, MDA was increased by 12.4% (P<0.05), but the activities of SOD and Na+-K+ ATPase were decreased by 8.2% and 18.9% respectively (all P <0.05) in comparison to saline group. HO-1 expression was detectable in the neurons and gliacytes of the ipsilateral cerebral cortex infarc-tion area at 30 min after MCAO. With time going on, the expression of HO-1 was increased. Conclusion CO can protect brain tissues wfocal cerebral ischemia. The expression of HO-1 protein is evidently sig-nificant physiological consequences in the recovery of neuronal tissue from ischemic injury in focal cerebral ischemia. Key words: Focal cerebral ischemia;  Carbon monoxide;  Lipid peroxidation;  Heine oxygen-ase