Investigation Of Retinal Function Changes In Rats Exposed Acutely To High Altitude And Intervention Effects Of Resveratrol

Objective To investigate the influence of hypobaric hypoxia on the retina by establishing the model of hypobaric hypoxia,and study the protective effects of resveratrol on rat retina hypoxic damage and explore the mechanism involove in the pathological progress.Methods 72 SD rats were randomly divided into the control group?hypoxic group and resveratrol intervention group.The control croup was feeding at 2260 m above sea level,the hypoxia group and the resveratrol intervention group were maintained at low pressure oxygen cabin(simulation for 5000 m above sea level)for a full 24 hours a day.Resveratrol intervention group was given daily intraperitoneal injection(30mg·kg-1,once a day).Retinal tissue was gentlely removed from each group and observed by HE staining after rats were treated for 7 days,the microstructure changes of optic nerve was also analysed under the electron microscope.The levels of superoxide dismutase(SOD)and Glutathione peroxidase(GSH-PX)in retina were detected by enzyme-linked immunosorbent assay(ELISA);The immunohistochemical expression of glial fibrillary acidic protein(GFAP)and hypoxia-inducible factor-1(HIF-1)in retina were detected by immunohistochemical methods.The expression of Nuclear factor-kappa B(NF-?B)?hypoxia inducible factor(HIF)?Superoxide Dismutase(SOD)and brain-derived neurotrophic factor(BDNF)were evaluated by RT-PCR.Results Compared with control group,the obvious pathological changes and increased immunostaining of GFAP and HIF-1 presented in retina of hypobaric hypoxia model group.The decreased level of GSH-PX(P=0.001)and theupregulated m RNA expression of BDNF(P=0.001),NF-?B(P=0.002)and HIF(P=0.034)were shown in hypoxia group when comparing to the control group,and there were significant differences,but no statistical diffieren was shown in the level of SOD(P=0.088)and SOD m RNA(P=0.262).The decreased expression of GFAP and HIF-1 and increased acitivity of GSH-PX exhibited in resveratrol intervention group(P=0.004),the m RNA level of HIF and BDNF down regulated(P=0.001,0.021),there were significant differences compared with hypobaric hypoxia model group.The m RNA level of NF-?B and SOD decreased in resveratrol group,but there was no significant difference as compared with hypoxbaric hypoxia model group(P=0.090,0.887).The measeured parameters in resveratrol intervention group have no statistical difference compared with control group.Conclusion Acute hypobaric hypoxia might cause the pathological changes of rat retina.The intervention of resveratrol showed a protective role on acute hypobaric hypoxia induced retina impairment by increasing antioxidant production including SOD and GSH-PX,meanwhile enhancing the ability to remove the free radicals and regulating the expression of HIF,BDNF and GFAP.