碱性成纤维细胞生长因子在挫伤性视网膜病变大鼠中的治疗作用

Therapeutic effect of basic fibroblast growth factor on contusion injury of the rat retina

目的:观察玻璃体腔内注射碱性成纤维细胞生长因子(bFGF)对挫伤性视网膜病变大鼠的治疗作用。方法:自由落体法制作视网膜挫伤模型。将SD大鼠随机分为正常组、挫伤组及治疗组。挫伤后即刻,挫伤组大鼠玻璃体腔内注入10 lμ生理盐水,治疗组注入bFGF 10 lμ(含bFGF 2μg),行HE染色观察各组大鼠视网膜组织的病变情况;测量视网膜内外层厚度;采用末端脱氧核酸转移酶介导的脱氧三磷酸尿苷缺口末端标记(TUNEL)法检测感光细胞凋亡情况,并计算凋亡指数。结果:视网膜挫伤早期,治疗组大鼠视网膜水肿较挫伤组轻,后期各时间段治疗组大鼠视网膜外核层厚度均比挫伤组厚。TUNEL染色显示挫伤组于3 d时视网膜可见较多凋亡阳性表达的细胞,分布在外核层,余各组未测到阳性着色细胞。与挫伤组比较,bFGF治疗组在挫伤3 d时凋亡的感光细胞明显减少。结论:玻璃体腔内注射bFGF能抑制挫伤性视网膜病变大鼠感光细胞的凋亡,从而对其有治疗作用。

Objective： To explore the therapeutic effect of basic fibroblast growth factor （bFGF） injected into the vitreous cavity on contusion injury of the rat retina. Methods： The animal model of retinal injury was created by a free falling iron bar hitting the cornea. The rats were divided into normal, contusion and treatment groups randomly. At the beginning of contusion, normal saline and 2 p.g of bFGF were injected into the vitreous cavity in contusion group and the treatment group respectively. The morphologic changes of retina were observed by HE staining. The thickness of outer and inner nuclear layer of retina was measured. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling （TUNEL） technique was used to assess apoptosis of photoreceptor cells. The relative proportion of apoptotic cells was measured by apoptosis index. Results： In the primary period of retinal contusion injury, the edematous status of retina in treatment group was lighter than that in the contusion group. The retinal outer layer thickness in treatment group were greater than that in the contusion group during all the post-contusion stages. There was a number of TUNEL positive apoptotic photoreceptor cells at the time of 3 d after contusion. TUNEL positive photoreceptor cells could not be seen at other groups. But the number of apoptotic photoreceptor cells decreased obviously in the treatment group. Conclusion： Injection of bFGF into the vitreous cavity can inhibit photoreceptor cell apoptosis and has the therapeutic effect on contusion injury of the rat retina.