缺血后处理联合异丙酚后处理对大鼠肢体缺血再灌注诱发视网膜损伤的影响

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

目的 评价缺血后处理联合异丙酚后处理对大鼠肢体缺血再灌注诱发视网膜损伤的影响.方法 选择雄性Wistar大鼠24只,采用随机数字表法,将其分为3组（n=8）：假手术组（S组）、肢体缺血再灌注组（LIR组）、异丙酚后处理＋缺血后处理＋肢体缺血再灌注组（P＋ I＋ LIR组）.采用分离并结扎双侧后肢股动、静脉60 min后恢复灌注的方法建立肢体缺血再灌注模型.P＋I＋LIR组缺血60 min后再灌注5 min,继之重新缺血5 min,再灌注5 min,循环4次后恢复灌注,并于再灌注同时腹腔输注异丙酚500 μg· kg-1·min-,在缺血期停止输注,循环4次.于再灌注120 min时采集腹主动脉血样,测定血清MDA浓度.摘取眼球取视网膜组织,HE染色后观察病理学结果.结果 与S组比较,LIR组血清MDA浓度升高（P＜0.05）,P＋ I＋ LIR组血清MDA浓度差异无统计学意义（P＞0.05）;与LIR组比较,P＋I＋LIR组血清MDA浓度降低（P＜0.05）.S组视网膜结构正常,LIR组视网膜全层水肿,节细胞层大量空泡变性,结构紊乱;P＋ I＋ LIR组视网膜病理学改变显著减轻.结论 缺血后处理联合异丙酚后处理可减轻大鼠肢体缺血再灌注诱发视网膜损伤,其机制与抑制脂质过氧化反应有关.

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.