rHEPO对大鼠急性视网膜光损伤的保护作用及时效性研究

Protective Effect and Timeliness of Recombinant Human Erythropoietin on Acute Retinal Light Injury in Rats

目的探讨重组人促红细胞生成素(r HEPO)对大鼠急性视网膜光损伤的保护作用及时效性.方法选取4周龄雄性SD大鼠48只,随机分成5组:正常对照组、模型对照组、模型治疗1、2、3组,其中正常对照组8只,其余各组均为10只,应用手术显微镜(光照强度为(22 000±1 000)lux)对模型各组造模.模型治疗1、2、3组:分别在光照前4 h、光照后立即、光照后3 d按照5 000 IU/kg腹腔注射r HEPO 1次.模型对照组:光照前后均未给予药物干预.7 d后处死所有大鼠,摘取眼球,应用苏木精-伊红(HE)染色观察视网膜的变化;应用免疫组织化学的方法检测Caspase-3的表达.结果 1)HE染色:正常对照组中大鼠视网膜各层结构完整,层次分明,排列整齐,细胞核形态规整,染色均匀.模型对照组中大鼠视网膜光感受器内、外节排列紊乱,有空泡形成,部分断裂;外核层较正常对照组明显变薄(P<0.05),核间隙加大,部分有碎核现象.模型治疗各组大鼠视网膜光感受器内、外节排列紊乱,有小空泡形成;外核层较正常对照组有不同程度变薄(P<0.05),模型治疗1、2组好于模型对照组(P<0.05),且1组优于2组(P<0.05),模型治疗3组与模型对照组比较差异无统计学意义.2)Caspase-3表达:与正常对照组相比,模型各组的Caspase-3表达均有所增强(P<0.05);模型治疗1、2、3组表达依次增强,两两比较差异具有统计学意义;模型对照组与模型治疗3组表达最强,二者之间无差异(P>0.05).结论 r HEPO对视网膜光损伤具有保护作用,并具有一定的时效性,早期用药效果好,其中光损伤前4 h预用药优于光损伤后立即用药.

Objective To observe the protective effect and timeliness of Recombinant Human Erythropoietin （rHEPO） on retinal light damage in rats. Method 48 rats with 4-week-old SD were randomly divided into 5 groups ： normal control group, model control group, model treatment group 1,2,3 ; 8 rats in normal control group and 10 rats in other groups. We used the light of surgical microscope to continuously irradiate the retina of SD ratsin model groups to form the model of retinal light damage. RHEPO were given by peritoneal injection to model treatment group 1,2,3 according to the following time successively ：4 hours before irradiation, immediately after irradiation,3 d after irradiation. All the rats were killed 7 days later and the eyes were excised. Hematoxylin eosin （HE） staining were applied to observe retinal changes. Immunohistochemistry methods were used to detect the expression of Caspase-3. Results Histology analysis：In normal control group, the retinal structure was complete and regular, and the staining was uniform. In model control group, the inner and outer segments of photoreceptor were arranged in disorder, the phenomenon of vacuolation and fracture were seen in outer segments. The outer nuclear layer became thinner （P〈0.05）, nuclear became denser and nuclear clearance became larger, rHEPO groups showed less damage than the model control group. There was significant difference between two groups except model treatment group 3 and model control group. Conclusion rHEPO is effective on repairing retinal light damage, but it has certain timeliness. Early intervention is more effective than later treatment, especially in 4 hours before light injury.