Protective Effect Of Astragalus Compound On Rat Retinal Mitochondrion Injury Caused By Acute Hypobaric Hypoxia

Objective: To explore the intervention mechanism of Radix Astragali seu Hedysari Compound?RAHC?on retinal injury in rats under acute hypobaric hypoxia.Methods: Totally 42 healthy SD rats were divided into3groups:normoxic control group,hypoxic group,and RAHC intervention group.Both the hypoxic group and RAHC intervention groups were fed at a hypobaric oxygen chamber?simulation for 5000 m altitude?and the RAHC group was given compound decoction 0.1g·kg^-1 by gavage.The eyeballs and retinas were collected after different treatments for 7 days.HE staining was processed for observing the morphological changes of rat retina.The expression of manganese superoxide dismutase?Mn SOD?was performed by RT-PCR.The activity of succinate dehydrogenase?SDH?was determined by colorimetry,and the level of cytochrome c oxidase?COX?was checked with enzyme-linked immunosorbent assay?ELISA?.Immunohistochemistry was performed to detect the expression of cytochrome C?Cytc?in rat retina.Results: Edema was found in the retina layers of the hypoxia group under the light microscope,and it was alleviated after the intervention of RAHC.The activity of Mn SOD in the hypoxia group(0.811 ± 0.057 U·mg^-1)was decreased compared with the control group(0.950 ± 0.920U·mg^-1)?P<0.05?,while RAHC intervention increased the level of Mn SOD(0.884 ± 0.101U·mg^-1)as compared to the hypoxic group?P<0.05?.SDH expression in the hypoxic group(22.009 ± 0.384U·mgprot^-1)was lower than that in the control group(30.104 ± 0.854U·mgprot^-1)?P<0.05?,and there was no obvious change after intervention with RAHC?P>0.05?.Hypoxia decreased COX activity(0.632 ± 0.031ng·ml^-1)when compared to the control group?P<0.01?,RAHC treatment upregulated the COX level and there was a statistic significance compared with the hypoxic group?P<0.01?.Positive brown staining of Cytc in retinal ganglion cell layer,retinal nerve fiber layer,inner plexiform layer and outer plexiform layer was strengthened in the hypoxic group,and it was down-regulated by RAHC.Conclusion: Acute hypobaric hypoxia can cause retinal damage by modulating the mytochondrion-related genes.RAHC exerts protective effects on retinal damage by upregulating MnSOD and COX activity as well as reducing the Cytc release.