Effect of propfo ol on neu ronal MMP-9 expr se sion after brain injury in rats

doi:10.3969/j.issn.1002-7386.20141.6.001

Abstract：Objective To observe the effect of propofol on neuronal MMP-9 expression after brain injury in rats and to explore its action mechanisms in neuroprotective effects .Methods Ninety-one health male Wistar rats were randomly divided into sham-operation group , saline group ( saline treatment after brain injury ) , propofol group ( propofol treatment after brain injury).Propofol dose was clinical anesthesia relevant dose (100mg/kg),which was injected intraperitoneally 15 min afterbrain frostbite ,once every 2 hours.The brain frostbite models were established by skull external intelligence frostbite method,then the brain tissues were collected at 2, 6,24 hours after frostbite.The brain water content was detected by dry wet weight method;the expression levels of MMP-9 mRNA were detected by RT-PCR;expression levels of MMP-9 protein were detectedby immunohistochemistry .Results The brain water content in saline group in different time points was significantly higher than that in sham-operation group( P <0.01),which peaked at 24 hours after brain frostbite.The brain water content in propofol group was significantly lower than that in saline group at 6,24 hours after brain frostbite( P <0.05 or P <0.01). The expression levels of MMP-9 mRNA in sham-operation group were decreased , however , which in saline group were significantly increased at 2 hours after brain frostbite,as compared with those in sham-operation( P <0.01),which peaked at 6 hours,continued at 24 hours( P <0.01).The expression levels of MMP-9 mRNA in propofol group were significantly decreased at 6,24 hours after brain frostbite,as compared with those in saline group( P <00.5 or P <0.01).The expression levels of MMP-9 protein in saline group were significantly increased at 2 hours after brain frostbite ,as compared with those in sham-operation group,which peaked at 6 hours,continued at 24 hours( P <00.1 ).The expression levels of MMP-9 protein in propofol group were significantly decreased at 6h,24h after brain frostbite,as compared with those in saline group ( P <0.05 or P <0.01).Conclusion Propofol at clinical anesthesia relevant dose can relieve brain edema after brain injury ,which may be correlated to the inhibitory effect of propofol on expression of MMP-9.