AIM:To investigate the protective effect of complex thrombolysis capsule on high altitude retinopathy in rat models and its possible mechanism.

METHODS: Twenty-four adult male SD rats were randomly divided into 6 groups and were put into plateau environment simulation experimental chamber at simulated altitude of 5 000m for 2, 4, 6, 10, 24, 72h respectively. Retinal pathology, HIF-1α and the b wave amplitudes of Max-R of flash ERG were examined by HE,IHC and flash ERG. Twenty-four adult male SD rats were randomly divided into 4 groups and were given respectively placebo, rhodiolarosea, inosine tablet and compound xueshuantong capsule by gavage for 7d. They were put into plateau environment simulation experimental chamber at simulated altitude of 5 000m for 10h. Retinal pathology, HIF-1α and the b wave amplitudes of Max-R of flash ERG were examined by HE, IHC and flash ERG.

RESULTS: In the SD rat model of high-altitude retinopathy, with the increase of experimental time, the ganglion cell layer of rat's retina showed obvious edema and HIF-1α expression increased in the cytoplasm of ganglion cells and core cells. All of them were most obvious at 10h. Compared with the self-comparison of b wave amplitudes of Max-R of flash ERG in each group of SD rats before and after entering in plateau environment simulation experimental chamber, the b wave amplitudes of Max-R in 4h, 6h, 10h and 72h were dramatically decreased(P﹤0.05). And the 2h, 4h(P=0.007), 6h(P=0.008), 10h(P=0.002)were statistically significant differences, the 24h and 4h(P=0.035), the 6h(P=0.040)and 10h(P=0.012)were also statistically significant differences. In the study of protective effect of complex thrombolysis caps on high altitude retinopathy in rat models, the results showed that the rat retinal edema of rhodiolarosea group, inosine tablet group and compound thrombosis capsule group and HIF-1α expression in ganglion cell layer of compound thrombosis group and rhodiolarosea group were significantly reduced comparing with the placebo group. Test for homogeneity of variance and one-way ANOVA were used to test the difference of b wave amplitudes of Max-R of flash ERG in four groups of SD rats after entering in the plateau environment simulation experimental chamber, the results showed the complex thrombolysis caps group(P=0.032)and rhodiola rose group(P=0.001)was significantly lower than placebo group.

CONCLUSION: Compound thrombosis caps may have a protective effect on highaltitude retinopathy in rats by inhibiting the expression of HIF-1α, however, the specific mechanism needs to be further studied.