The Animal Model Research Of Rat Retina Pigment Epithetlium Cell Replicative Senescence Induced By Blue Light In Vivo

Objective:To observe the effect of senescence associated beta-galactosidae(SA—β—Gal) histochemical stain in rat retina pigment epithelium(RPE)cellreplicative senescence induced by different blue light intensions and times.Explore the relationship between the blue light and replicative senescence.Set up the animal model of replicative senescence,and provide the new theory with age-related macular degeneration(AMD) pathogenesis.Method:1.Thirty six 12-14weeks wistar rats,male and female unlimited,they are all healthy and no eye disease checked by ophthalmoscope and slit lamp.The rats rise in the case which hangs the blue light lamp(450±10nm).the rats divide into 4 groups by random,the group one is dark group,the group two is nature light group(the light intension is 30±10lux),the group three is 500lux light group(the light intension is 500±100lux),the group four is 1000lux light group(the light intension is 1000±200lux).Each group is 9 rats.Every group divides into 3 subsets:group A(1 month),group B(2 month),groupC(3month).2.At the 1,2,3month,the rats are anesthetized by the 10%chloral hydrate.Put out the right eye,take the paraffin section and HE stain,observe the section under the light microscope.Take the left eye to the SA—β—Gal histochemical stain and observe the positive cell under light microscope.Each eye select two integrity retina structure by SA—β—Gal histochemical stain.Each section selects 5 fields by random(×200 times),figure the positive cells in each field.3.The result put into the spss11.5 statistic software.The only illumination or only time group data use one way ANOVA,the different illumination and time groups datum use two way ANOVA,then compare the each group using SNK test,p＜0.05 has the statistic meaning.Result: 1.HE stain display that in the dark and nature light group,the rat retina has the regular layers,the photoreceptor cells are regular,the nuclear stains deep violet,the boundary is sharp.RPE cell nuclear is light violet,ellipse,clear and stain uniformity. Compared the group one,group three shows the irregular layers,the photoreceptor cell nuclear decreases and the form is irregular.RPE cell swelling and rounding,the stain light.Group four has similar changes with group three,but the degree are deeper, the express are more obvious.2.SA—β—Gal histochemical stain appears that under different illuminating intension and different illuminating time,with the two way ANOVA,with the different intensity of blue light groups,the rat RPE positive cells in SA—β—Gal histochemical stain are differents,and these difference between different exposure intensity are significant at the 0.05 level analyzed by statistics software spss11.5.(p= 0.000).So do the different illuminating time of blue light.We compare each group with SNK test,except the group one and group two,the difference among other groups all has significant statistic meaning(P=0.000).Under the only illumination intension factor,we use one way ANOVA,besides the group one among one month,two month,three month(P₁=0.687,P₂=1.000)and group two between one month,two month(P=0.406),the rat RPE positive cells in SA—β—Gal histochemical stain are differents among other groups,and these difference between different exposure intensity are significant at the 0.05 level analyzed by statistics software (P＜0.01).Under the only illumination time factor,we use one way ANOVA,at every time period,the rat RPE positive cells in SA—β—Gal histochemical stain are significant differents at the 0.05 level(P=0.000).then we use SNK test shows that besides every time period between the group one and group two(P= 0.767,P=0.494,P=0.079),the rat RPE positive cells in SA—β—Gal histochemical stain between other groups are significant differents at the 0.05 level.(P＜0.01)Conclusion:Our reseach sets up the model of rat retina replicative senescence,with the increasing of the intension of blue light and time of illumination,rat retina appear the changement of replicative senescence,and the changes depend on the time and intension of blue light,more attention is that nature light group through 3 month also appear replicative senescence.The stain positive cells arenot obvious compared the trial group,but it can display that the replicative senescence exist in the rat RPE cell under nature condition.