The Effect Of Brain Ischemic Precondition On The Activity Of ATPase And GSH-PX And The Level Of MDA In Rats

Objective:To investigate the effects of ischemic preconditioning on the activity of ATPase and GSH-PX and the level of MDA, and study further the mechanism of brain protection produced by ischemic preconditioning.Methods: 48 male SD rats (weight 230-300g) are randomly divided into 4 groups:false operation group(n=12), ischemic preconditioning group (n=12),ischemia group(n=12), ischemia after ischemic preconditioning group (n=12).False operation group:sew up the skin after exposing the common carotid artery (CCA) in right.Ischemic preconditioning group: a focal-focal cerebral ischemia model is induced by adopting the thread embolism method according to Longa with a little alteration. After blocking MCA blood flow for 30 minutes, the thread is pulled out, and the ECA nub is ligated.Ischemia group: a thread is inserted to MCA in the right side for a 24-hour brain ischemia.Ischemia after ischemic preconditioning group: the procedure is similar to ischemic preconditioning group, then 24 hours later, a thread is inserted to ACA in the right side through CCA for 24 hours.The following parameters are observed respectively in four groups: neural function according to Bederson method,HE dying,The activity of ATPase and GSH-PX and the level of MDA(n=12 per group).Results: The scores of neural function are 0, 0.25±0.20 , 2.24±0.87, 1.16±0.71 in false operation group, ischemic preconditioning group, ischemia group and Ischemia after ischemic preconditioning group respectively, and the difference is significant between ischemia after ischemic precond- itioning group and ischemia group(p<0.05), but there is no significant difference between false operation group and ischemic preconditioning group(p>0.05). The activity of ATPase, including Na+,K+ -ATPase and Ca2+,Mg2+-ATPase,the result of them respectively as following: false operation group are 3.72±1.52,3.58±0.59; ischemic preconditioning group are 3.58±0.78,3.69±0.32; ischemia group are 2.27±0.56, 2.34±0.5;ischemia after ischemic preconditioning group are 2.79±0.61, 2.85±0.65. the differ- rence is significant between Ischemia after ischemic preconditioning group and ischemia group (p<0.05), but there is no significant difference between false operation group and ischemic preconditioning group(p>0.05). the activity of GSH-PX:false operation group is 21.59±2.58, ischemic precon- ditioning grou is 22.21±3.55, ischemia group is 12.56±3.27, ischemia after ischemic preconditioning group is 16.02±1.82. the difference is significant between Ischemia after ischemic preconditioning group and ischemia group (p<0.05), but there is no significant difference between false operation group and ischemic preconditioning group (p>0.05). the level of MDA:false operation group is 3.55±1.04,ischemic preconditioning group is 3.89±0.53, ischemia group is 5.86±1.08, ischemia after ischemic preconditioning group is 4.29±0.95. the difference is significant between Ischemia after ischemic preconditioning group and ischemia group(p<0.05), but there is no significant difference between false operation group and ischemic preconditioning group(p>0.05).Conclusion: Ischemic precondition plays a important role in reducing the ischemic protection by increasing the activity of ATPase and GSH-PX .