| Objective:To investigate the effects of different high-altitude hypoxia on the rat retinal tissue and expression of HIF-la and p53. And explore the establishment of animal model of High altitude retinopathy in rats. Methods:The experiment started with 24 SD rats, which were divided into 4 groups with random number table. Each has 6 rats raised in the Plateau environment simulation chamber with oxygen partial pressures of 17.6 kPa,14.7 kPa,11.3 kPa and 7.4 kPa, which indoor simulated altitudes of 1500m,3000m,5000m and 8000m. After 6 hours put the rats to death and removal the eyes to do HES to observe changes of rat retinal pathology, IHC showed the expression of HIF-la and p53, MetaMorph image analysis software was used to calculate the mean absorbance of positive cells value. Then analyzed the correlation between HIF-la and p53 expression. Results:when the simulated altitude at 1500m, the retinal structure and layers of tissue was clear, as well as the retinal thickness was uniform, the ganglion cell monolayer, the nucleus is large and oval. The weakly expression of HIF-la and p53 were only in the ganglion cell layer of retina at 1500m. When the simulated altitude at 3000m, the rat retina layers of tissue was loose and edema, retinal thickness increased and levels disordered. HIF-la and p53 expressed in the ganglion cell layer and inner nuclear layer. When the simulated altitude at 5000m, the rat retinal ganglion cell layer and plexiform layer was more edema, and the ganglion cells were swelling and degeneration. the expression of HIF-1α and p53 were enhanced. While the simulated altitude at 8000m, the rat retinal ganglion cell layer membrane and plexiform layer of loose and edema were more obvious, some cells showed with karyopyknosis, nuclear dissolved and reduce of cells number. The enhanced expression of HIF-la and p53 were more obvious. And the expression of HIF-la and p53 were positive correlation in the retina (r=0.9846, P<0.05). Conclusion:The simulated high altitude-hypoxia can cause the injury of retinal tissue and led to the pathological changes, and with the altitude getting higher, the oxidative damage getting more serious, which means the rat model of High altitude retinopathy established successfully. While analyzed its mechanism may be associated with the upregulation of HIF-1α and p53 expression.Objective:To observe the effects of Rhodiola on the rat retinal tissue morphology, as well as the HIF-1α and p53’s exprssion of simulated hypoxia at different altitudes. Methods:36 adult female Sprague Dawley rats were randomly divided into the Rhodiola Intervention group (Intervention group) and the Saline group(Control group), each group had 18. The Intervention group rats were treated with 10ml/kg dose of Large plants Rhodiola Injection with intraperitoneal injection, and the Control group rats were injected with saline in the same dose.1 hour after the injection, both of the two groups were randomly selected 6 rats reared with the oxygen partial pressure of14.6 kPa,11.3 kPa and 7.4 kPa in the plateau environment simulation laboratory modules, which simulated the altitudes of 3000m,5000m and 8000m indoor. After 6 hours removal of the rat eyeball made paraffin sections. Using Hematoxylin and Eosin staining to observe the pathological changes in the retina, and Immunohistochemical staining to observe the expression of HIF-1α and p53 in the rat retinal, and analyzed the correlation between HIF-1α and p53 expression. Results:In Control group, the tissue layers of rat retinal were edema and loose, retinal thickness increased, the retinal levels was disorder, the ganglion cell was swelling degeneration, and some can observe the karyopyknosis, karyolysis and the reducing of cells number. As the altitude increased, the pathological changes of retinal became more obvious. In Intervention group, the characteristics of rat retinal morphology were same with Control group, while the degree of morphology changes was lighter than Control group. HIF-1α and p53 expressed mainly in the ganglion cell layer and inner nuclear layer of rats retina in Control group. As altitude increased, expression of HIF-1α and p53 were increased too. Compared with the Control group, the rat retinal expression of HIF-1α increased, while expression of p53 decreased in Intervention group, and there were statistically significant differences (P<0.05). Conclusion: Rhodiola can improve the retinal tissue pathology damage caused by high altitude hypoxia, and its mechanism may be related to the increasing expression of HIF-1α and the reducing expression of p53. |
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