AIM: To investigate the effects of astragalus injection on the metabolic and pathological changes of the retinal free radical metabolism and pathology in high-altitude hypoxic rats.

METHODS:Sixty healthy SD rats without any eye disease were selected, and the random grouping method was divided into two groups: astragalus injection group(intervention group)and physiological saline group(control group), each group of 30 rats. In each group, 6 were randomly selected for injection of astragalus injection(15mL/kg)and physiological saline(15mL/kg)in the pre-simulated chamber. The rats were sacrificed immediately and removed the eyeballs after the rats were taken out of the simulated module. We observed the changes of retinal morphology with the HE staining method, and determine the retinal SOD and MDA content with colorimetry.

RESULTS:HE staining showed no morphological changes in the two groups of retinas at 2h, and as the time of hypoxia was prolonged, the retinal edema gradually increased, but the intervention group was less edema than the control group. The activity of SOD in both groups decreased with the increase of anoxia time of high altitude, and the comparison of different time points in the group was statistically significant(P<0.05). The content of MDA in both groups increased gradually, and the comparison between different time points in the group was statistically significant(P<0.05). The SOD in the two groups of retinas was significantly different at same time point(P<0.05), except for at 2h without statistical significance. The MDA showed the same situation as SOD.

CONCLUSION: Astragalus injection can reduce the damage degree of retinopathy in rats under the high altitude hypoxia environment, that the mechanism may be related to free radicals, enhance the activity of SOD, reduce the MDA content of lipid peroxides, and enhance antioxidant capacity.