The Experimental Study Of N-acetylcysteine Protection Against Brain Ischemic Reperfusion Injury Of The Rat

ObjectiveTo study the protection of a new Antioxidant N-acetylcysteine(NAC) against cerebral ischemia-reperfusion injury (CI/RI) of the rat.Methods Focal cerebral ischemia-reperfusion model was made by improved Longa's method inSprague-Dawley rats. 66 healthy male Sprague-Dawley Rats(3 to 5 monthes old, weight 250g to 300g) were randomly divided into normal control group(A), sham operated group(B), ischemic reperfusion group(C) and NAC group(D). At the same time,the ischemic reperfusion group(C) were randomly divided into ischemic reperfusion of 6,12,24,48 and 72 hours group respectively;And the NAC group(D) were randomly divided into 24 and 48 hours group respectively;The ischemic reperfusion group and the NAC group were reperfusion after 2 hours of middle cerebral artery occlusion. The NAC group were accepted an intraperitoneal injection of N-acetylcysteine (150mg/kg) before 30minites of MCA occlusion, and followed by another dose after 24 hours(48 hours group). While Group C were accepted the same doses of saline, Group C and group D were removed the brains at each hour respectively; Group A were removed the brains immediately;Group B were removed the brains at the 24th hour after operation. Then the neurological deficit score and the infarction volume would be observed and compared and c-fos-positive cells and Survivin-positive cells would be calculated and compared in Group C and Group D. the changes of the c-fos-positive cells and Survivin-positive cells would be observed in Group C as the time went by.Results1. The neurological deficit score of Group D was better than Group C(P<0.05);2. The infarction volume of Group D was minner than Group C(P<0.01);3. There were more Survivin-positive cells in Group D than Group C(P<0.05), while there were fewer c-fos-positive cells in Group D than Group C(P<0.01).4. As the time went by, the Survivin-positive cells in Group C became more and more, and it reached the maximum at the 48th hour and it remained obviously at the 72th hour. While the c-fos expressed in Group C became fewer and fewer, it was notable at the 6th hour and not obviously at the 72th hour.Conclusion1.N-acetylcysteine may protect the brian from the ischemic reperfusion injury. The mechanism might be it can inhibit the apoptosis of the nerve cells and encourage the expression of Survivin in nerve cells indirectly.2.The expression of Survivin and c-fos in nerve cells are different as the time gose by. c-fos might be related with the injury of the nerve cells, while Survivin might be related with the recovery of the nerve cells.