The Protective Effect Of Pretreatment Of Probucol To Retina Ischemia Reperfusion Injury

Objective To study the effects and underlying mechanisms of probucol pretreatment to retina ischemia reperfusion injury.Methods Adult male Wistar rats were randomly divided into control, ischemia-reperfusion and probucol pretreated group. All rats were fed with standard rat diet for2weeks. The rats in ischemia-reperfusion group and probucol pretreated group were additionally taken normal saline(5ml/Kg body mass, twice a day per rat) and probucol suspension fluid (5ml/Kg body mass, twice a day per rat) by intragastric administration respectively. The model of RIR was accomplished on the right eye of adult male Wistar rats in ischemia-reperfusion and probucol pretreated group by increasing the intraocular pressure to14.3Kpa for60minutes via cannulation into the anterior chamber.10rats of ischemia-reperfusion group and prbucol pretreated group were randomly sacrificed by cervical dislocation. And retina tissue sections and retinal tissue homogenates were made. Retinal histological changes were observed under the microscope. The apoptosis of Retinal neurons was observed by TdT-mediated dUTP nick end labeling (TUNEL). The contents of malondialdehyde (MDA), superoxide dismutase (SOD) in the retina of rats were measured by photometry.Results (1) The inner layer of retina swelled and thickened during the early period after RIR. At later stage the inner layer of retina atrophy and became thinner. The edema degree of retina in probucol pretreated group was lighter than that in ischemia-reperfusion group. The inner layers of retina in probucol pretreated group were thicker than that in ischemia-reperfusion group at later stage after reperfusion (P <0.05).(2) Few apoptosis cells were observed in the rat retina of control group. Apoptosis cells began to increase at6hour after reperfusion and peaked at24hour. Apoptosis changes in probucol group appear similar trend with the ischemia-reperfusion group, however less apoptosis cells of rat retina were observed in the probucol pretreated group than in ischemia-reperfusion group6hour after reperfusion (P<0.05).(3) The content of MDA in rat retina of ischemia-reperfusion group increased after reperfusion. And it was more than that of control group from6 hour to72hour after reperfusion (P<0.05). The content of MDA in rat retina changes in probucol group appear similar trend with the ischemia-reperfusion group, however it was lower than that in ischemia-reperfusion group6hour after reperfusion (P<0.05). The activity of SOD in rat retina of ischemia-reperfusion group decreased gradually after reperfusion, and it was much lower than that of control group6hour after reperfusion (P<0.01). The activity of SOD in rat retina of probucol pretreated group was lower than control group from12hour to72hour after reperfusion (P<0.01). The activity of SOD in rat retina of probucol pretreated group was higher than ischemia-reperfusion group from1hour to24hour after reperfusion (P<0.05)Conclusions Pretreatment with probucol can reduce the injury to retina caused by ischemia reperfusion. The possible protective mechanism is that probucol can reduce retinal neurons apoptosis and improve of the antioxidant capacity of retina and decrease the formation of retinal tissue lipid peroxide.