| Objective: To study the influence of acute hypobaric hypoxia on retinal DNA in rats and intervention efficacy of Radix Astragali seu Hedysari Compound(RAHC).Methods:72 healthy SD rats were randomly divided into normal control group,hypoxic model group and RAHC intervention group.The control group was housed in normal condition.Hypoxic model group and RAHC intervention group were maintained at a low-pressure oxygen chamber,which simulated an altitude of 5,000 meters.The RAHC intervention group was given RAHC once a day(0.1g/kg),and hypoxic rats were administered with the same amount of normal saline.Retinal tissue was obtained after rats were treated with different ways for 7 days.HE staining was performed to observe the pathological morphology of retina in each group.The expressions of p53 and histone family 2A variant(?H2AX)for detecting DNA damage and repair were analyzed by immunohistochemistry.The m RNA levels of 8-oxoguanine nucleoside triphosphatase(MTH1)and 8-hydroxyguanine glycosylase(8OGG1)were determined by real time-PCR.Results: Increased immunohistochemical expressions of p53 and ?H2AX were observed in the retinas of the hypoxic model group as compared to the control group.Hypobaric hypoxia notably downregulated the relative m RNA expression of MTH1(0.5728±0.0813)and 8OGG1(0.7717±0.1358)when compared with normal controls(0.8455±0.1601 and 1.0132±0.1683 respectively,P<0.05).RAHC mitigated the retinal damage by down-regulation of p53 and ?H2AX expressions in rat retinas;meanwhile,the administration of RAHC significantly enhanced the MTH1(0.7484±0.1139)m RNA level when compared to the hypoxic model group(P<0.05).No significant difference(P=0.743)was seen in 8OGG1 m RNA level between RAHC intervention group and hypoxic model group.Conclusion: The intervention of RAHC plays a protective role in hypobaric hypoxiainduced retinal damage through modulating the gene expression of p53,?H2AX,MTH1 and 8OGG1. |
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