Effects of octanol on MMP-9 and TIMP-1 protein expression and brain edema after ischemia reperfusion in rats

Abstract

Objective To investigate the treatment of octanol on matrix metalloproteinase-9(MMP-9) and tissue inhibitor of metalloproteinase-1(TIMP-1) protein expression, cerebral water content , infarction volume after ischemia-reperfusion in rats. Methods 150 SD rats were randomly divided into sham operated group (n=24), MCAO group (n=24) , DMSO solvent control group (n=24) and octanol treatment group (n=24). A model of middle cerebral artery occlusion was induced by suture method. TTC stain was used to detect the infarction volume, dry-wet weight method to determine the brain water content. The expression of MMP-9 and TIMP-1 protein was detected by immunofluorescence and Western blot. Results At 24 h of reperfusion after ischemia for 2 h, the octanol treatment group compared with MCAO group brain infarction volume obviously decreased(P<0.05), water content significantly reduced((78.16±1.47)% vs (80.88±0.73)%, P<0.05), the number of MMP-9 positive cells obviously decreased((10.67±2.16) vs (29.00±3.40), P<0.05), the expression of MMP-9 protein significantly reduced ((0.14±0.01) vs (0.21±0.02), P<0.05)and the number of TIMP-1 positive cells significantly increased ((27.83±2.13) vs (5.67±1.03), P<0.05), the expression of TIMP-1 protein obviously increased((0.42±0.01) vs (0.28±0.01), P<0.05). The difference between MCAO group and DMSO solvent control group was not statistically significant(P<0.05). Conclusion Octanol may reduce brain edema, brain infarction volume.Up-regulation the expression of MMP-9 and down-regulation the expression of TIMP-1 may be one of the underlying mechanisms of the octanol neuroprotection. Key words: Octanol; Reperfusion injury; Brain edema; Matrix metalloproteinase-9; Tissue inhibitor of metalloproteinase-1