目的：探讨丹酚酸B对视网膜静脉阻塞(RVO)损伤大鼠模型视网膜的保护作用及对血管新生的影响。

方法：SD大鼠随机分为对照组、模型组和丹酚酸B组，每组各10只，除对照组外，模型组和丹酚酸B组大鼠均采用孟加拉红联合激光光动力法诱导RVO，其中丹酚酸B组大鼠腹腔注射丹酚酸B 50mg/(kg·d)，对照组和模型组大鼠仅给予等量生理盐水，连续21d。荧光素眼底血管造影(FFA)技术观察给药前后视网膜静脉结构； HE染色观察大鼠视网膜组织病理变化； 视网膜电图(ERG)评估大鼠视网膜功能； 免疫荧光染色技术检测各组大鼠视网膜组织中血管内皮生长因子A(VEGFA)荧光表达情况； Western blotting法检测视网膜组织中HIF-1α、STAT3、p-STAT3及VEGFA蛋白相对表达量。

结果：与对照组比较，模型组大鼠视网膜阻塞处血流再通，有效侧支循环丰富，但形状不规则，有荧光渗漏； 丹酚酸B组大鼠视网膜静脉循环恢复，形状逐渐规则，血管侧支减少； 模型组和丹酚酸B组视网膜有不同程度病理损伤，同时两组大鼠ERG a波和b波振幅、视网膜总层(RTL)、内核层(INL)和外核层(ONL)厚度降低，VEGFA荧光强度增强，HIF-1α、p-STAT3及VEGFA蛋白相对表达量升高(P<0.05)； 与模型组比较，丹酚酸B大鼠视网膜组织病理学损伤有所减轻，ERG a波和b波振幅、RTL、INL和ONL厚度升高，VEGFA荧光强度减弱，HIF-1α、p-STAT3及VEGFA蛋白相对表达量降低(P<0.05)。

结论：丹酚酸B可减轻RVO大鼠视网膜组织病理学损伤，改善视网膜功能，这可能与抑制HIF-1α/STAT3/VEGFA途径激活，减少血管新生有关。

METHODS: SD rats were randomly divided into control group, model group and salvianolic acid B group, with 10 rats in each group. In addition to the control group, rats in model group and salvianolic acid B group were induced RVO by Bengal red combined with laser photodynamic method. The rats in salvianolic acid B group were intraperitoneally injected with salvianolic acid B 50 mg/(kg·d), while the rats in control group and model group were only given the same amount of normal saline for 21 consecutive days. Fundus fluorescein angiography(FFA)was used to observe the retinal vein structure before and after administration. HE staining was used to observe the pathological changes of rat retina. The retinal function of rats was evaluated by electroretinogram(ERG). The fluorescence expression of vascular endothelial growth factor A(VEGFA)in retina of rats in each group was detected by immunofluorescence staining. The relative expression of HIF-1α, STAT3, p-STAT3 and VEGFA proteins in retinal tissue were detected by Western blotting.

RESULTS: Compared with the control group, the blood flow at the retinal obstruction in the model group was recanalized, and the effective collateral circulation was abundant, but the shape was irregular, and there was fluorescence leakage. In salvianolic acid B group, the retinal vein circulation recovered, the shape became regular gradually, and the collateral vessels decreased. The retina of the model group and salvianolic acid B group showed different degrees of pathological damage. At the same time, the amplitude of ERG a wave and b wave, the thickness of retinal total layer(RTL), inner nuclear layer(INL)and outer nuclear layer(ONL)decreased, the fluorescence intensity of VEGFA enhanced, and the relative expression of HIF-1α, p-STAT3 and VEGFA protein increased(P<0.05). Compared with the model group, the retinal histopathological damage of salvianolic acid B rats was alleviated, the amplitude of ERG a-wave and b-wave, the thickness of RTL, INL and ONL were increased, the fluorescence intensity of VEGFA was weakened, and the relative expression of HIF-1α, p-STAT3 and VEGFA proteins was decreased(P<0.05).

CONCLUSION: Salvianolic acid B can alleviate the retinal histopathological injury and improve retinal function in RVO rats, which may be related to inhibiting the activation of HIF-1α/STAT3/VEGFA pathway and reducing angiogenesis.