Effects of postconditioning with ischema and propofol on retinal injury induced by limb ischemia-reperfusion in rats

Abstract

Objective To evaluate the effects of postconditioning with ischema and propofol on retinal injury induced by limb ischemia-reperfusion (LIR) in rats.Methods Twenty-four male Wistar rats were randomly divided into 3 groups (n =8 each) using a random number table:sham operation group (group S),group LIR,and propofol postconditioning + postconditioning + ischemic LIR group (group P + I + LIR).The model of LIR was established by separating and ligating the femoral artery and vein of bilateral hind limbs for 60 min followed by reperfusion.In group P + I + LIR,the animals were subjected to 4 episodes of 60 min ischemia-5 min reperfusion-5 min ischemia-5 min reperfusion and to 4 cycles of propofol 500 μg· kg-1 · min-1 infused intraperitoneally at the same time (during reperfusion)-no propofol infusion during second ischemia.At 120 min of reperfusion,blood samples were collected from the abdominal aorta for determination of serum malondialdehyde (MDA) concentrations.The eyeball was removed and the retina was cut into sections which were stained with H.E.and examined by microscopy.Results Compared with group S,the serum MDA concentration was significantly increased in group LIR,and no significant change was found in the serum MDA concentration in group P + I + LIR.The serum MDA concentration was significantly lower in group P + I + LIR than in group LIR.The structure of retina was normal in group S,oedema was found in all the layers of retina,vacuolar degeneration was observed in the most of ganglionic layers,and the structure disturbance was found in group LIR.The pathological changes of retina were significantly attenuated in group P + Ⅰ + LIR.Conclusion Postconditioning with ischema and propofol can attenuate retinal injury induced by LIR,and the mechanism is related to inhibition of lipid peroxidation in rats. Key words: Propofol ; Extremities ; Reperfusion injury ; Retina ; Ischemic postconditioning