急性高眼压模型大鼠视网膜病理变化及视网膜中胶质原纤维酸性蛋白表达变化动态观察

Dynamic observation of retinal pathology and glial fibrillary acidic protein expression changes in retina of acute ocular hypertension model rats

目的动态观察急性高眼压模型大鼠视网膜病理变化及视网膜中胶质原纤维酸性蛋白(GFAP)表达变化,探讨急性高眼压大鼠视网膜的损伤情况。方法将24只SD大鼠随机分为正常对照组6只和急性高眼压模型组18只,正常对照组不做任何处理。急性高眼压模型组采用沿角巩膜缘结膜下环扎缝合法制备急性高眼压模型。急性高眼压模型组大鼠造模前、缝合即刻、缝合后1 h、缝合后1 d、缝合后2 d、缝合后3 d、缝合后4 d、缝合后5 d、缝合后7 d时,分别使用Tonolab眼压计监测眼压,正常对照组于同一时间点测量眼压。取急性高眼压模型组大鼠,于缝合后1 d、缝合后3 d、缝合后7 d时分别处死后,采用HE染色法观察视网膜组织形态变化,采用Thy-1免疫组化染色法测算视网膜神经节细胞数量,采用免疫组织化学染色法检测视网膜中GFAP蛋白。结果急性高眼压模型组大鼠缝合即刻、缝合后1 h、缝合后1 d、缝合后2 d眼压均高于正常对照组(P均<0.05),且急性高眼压模型组大鼠缝合即刻、缝合后1 h、缝合后1 d、缝合后2 d眼压均高于其他时间点眼压,呈下降趋势(P均<0.05)。正常对照组视网膜各层结构未发生明显改变,急性高眼压模型组大鼠缝合后1 d时视网膜神经纤维层出现水肿,大鼠缝合后3 d时视网膜水肿开始减轻,大鼠缝合后7 d时视网膜厚度及神经纤维层厚度均变薄。急性高眼压模型组大鼠缝合后3 d、7 d时视网膜神经节细胞数量均低于正常对照组和急性高眼压模型组大鼠缝合后1 d时(P均<0.05),且急性高眼压模型组大鼠缝合后7 d时视网膜神经节细胞数量低于缝合后3 d时(P均<0.05)。正常对照组、急性高眼压模型组大鼠缝合后1 d、3 d、7 d时大鼠视网膜中GFAP蛋白表达水平分别为65.762±16.246、115.777±18.780、145.056±9.777、169.751±10.378,两两相比,P均<0.05。结论急性高眼压模型大鼠视网膜发生病理变化,出现神经节细胞丢失,视网膜中GFAP蛋白表达升高。

Objective To dynamically observe the pathological changes of the retina and the expression changes of glial fibrillary acidic protein(GFAP)in the retina of acute ocular hypertension model rats,and to explore the retinal damage in rats with acute ocular hypertension.Methods Twenty-four SD rats were randomly divided into the normal control group of 6 rats and acute ocular hypertension model group of 18 rats.Rats in the normal control group were not treated,while in the acute ocular hypertension model group,we prepared the acute ocular hypertension models by circumlimbal suture.The intraocular pressure was monitored in the acute intraocular hypertension model group before modeling,immediately after suturing,at 1 h after suturing,1 day after suturing,2 days after suturing,3 days after suturing,4 days after suturing,5 days after suturing,and 7 days after suturing using Tonolab tonometer,and the intraocular pressure was measured in the normal control group at the same time point.Rats from the acute intraocular hypertension model group were sacrificed at 1 day after suturing,3 days after suturing,and 7 days after suturing.HE staining was used to observe the changes in retinal tissue morphology,and Thy-1 immunohistochemical staining was used to measure the number of retinal ganglion cells,and immunohistochemical staining was used to detect GFAP protein in the retina.Results The intraocular pressure of rats in the acute ocular hypertension model group was higher than that of the normal control group immediately after suturing,at 1 h after suturing,1 day after suturing,and 2 days after suturing(all P<0.05),and the intraocular pressure was higher at 1 h after suturing,1 day after suturing,and 2 days after suturing than that at other time points,showing a downward trend in the acute ocular hypertension model group(all P<0.05).The structure of each layer of the retina in the normal control group did not change significantly.In the acute ocular hypertension model group,edema appeared in the retinal nerve fiber layer at 1 day after suturing,the retinal edema began to alleviate at 3 days after suturing,and both the retinal thickness and the thickness of the nerve fiber layer became thinner at 7 days after suturing.The number of retinal ganglion cells in the rats in the acute ocular hypertension model group at 3 and 7 days after suturing was smaller than that in the normal control group and that in the acute ocular hypertension model group at 1 day after suturing(both P<0.05);and the number of retinal ganglion cells in rats of the acute ocular hypertension model group at 7 days after suturing was smaller than that at 3 days after suturing(P<0.05).The expression levels of GFAP protein in the retina of rats in the normal control group and the acute ocular hypertension model group were 65.762±16.246,115.777±18.780,145.056±9.777,and 169.751±10.378,respectively at 1,3,and 7 days after suturing,with statistically significant difference(all P<0.05).Conclusion Pathological changes occurred in the retina of rats with acute ocular hypertension,including loss of ganglion cells and increased expression of GFAP protein in the retina.