The Effect Of α-lipoic Acid On VEGF And MMP-9 Levels In Rat Retinal Ischemia/reperfusion Injury

Objective To investigate the effect and mechanism of a-lipoic acid on vascular endothelial growth factor and matrix metalloprotelnase-9 in rat retinal ischemia/reperfusion injury.Methods Seventy eight Wistar rats were randomly divided into normal control group, treatment group (treated with a-lipoic acid,100 mg kg-1 day-1, i.p), ischemia group. The model of retinal ischemia/reperfusion injury was constructed by evelating the intraocular pressure. Intraocular pressure was increased to 110 mmHg for 60 minutes. Structural changes of retina were observed with light microscope, and the expression levers of VEGF and MMP-9 was measured at 6 hours,12 hours,24 hours,48 hours,3 days and 7 days after reperfusion by means of immunohistochemistry.Results VEGF and MMP-9 positive cells were rarely found in normal control group(AOD was 0.06±0.04 and 0.05±0.03). AOD of VEGF began to increase at 12 hours and reached maximal levels at 48 hours after RIRI in ischemia group 0.52±0.06 verse 0.35±0.05 in a-lipoic acid treated group. AOD of MMP-9 began to increase at 6 hours and reached the peak at 24 hours after RIRI in ischemia group 0.38±0.06 verse 0.29±0.05 in a-lipoic acid treated group. There was statistical difference in the level of VEGF and MMP-9 between ischemia group and normal control group (P<0.05) except AOD of VEGF at 6 hours after RIRI. There was statistical difference between a-lipoic acid treated group and ischemia group (P<0.05)with regard to the expression of VEGF and MMP-9. In ischemia/reperfusion group,the expression of VEGF was positively correlated to MMP-9(r=0.834,p＜0.05).Conclusion Retina ischemia/reperfusion injury can increase the expression of VEGF and MMP-9 and a-lipoic acid can protect retinal neurons from ischemia/reperfusion injury by inhibit the expression of VEGF and MMP-9 in rat retina.