方法：鼠龄7d的SD大鼠60只随机分为正常组、模型组、干预组和NS对照组共4组。正常组置于正常空气中饲养； 模型组置于75mL/L高氧环境5d建立氧诱导视网膜病变模型； 干预组给予抗p16甲基化药物5-aza-CdR(0.25mg/kg)腹腔注射； NS对照组腹腔注射同体积的生理盐水。各组分别取双侧眼球，左眼做HE染色观察视网膜新生血管，免疫组织化学和免疫荧光观察p16蛋白的表达。右眼视网膜行real time-PCR分析p16 mRNA的表达。

结果：正常组幼鼠的视网膜未发现突破视网膜内界膜的新生血管管腔。模型组和NS对照组视网膜组织明显增厚，可见大量新生血管管腔。干预组视网膜偶见新生血管管腔。免疫组织化学和免疫荧光显示，模型组视网膜p16呈低表达，阳性细胞数为19.52±2.67个； 而干预组阳性细胞数为36.38±3.16个，差异有统计学意义(P<0.001)。real time-PCR显示，模型组p16 mRNA的表达降低(2^-△△ct=0.14±0.01)，p16 mRNA在干预组大鼠的视网膜表达明显高于NS对照组大鼠视网膜，两组相比差异有统计学意义(2^-△△ct=0.68±0.08，P<0.001)。

结论：P16的异常表达可能与视网膜新生血管增殖密切相关，抑制p16甲基化可减少视网膜新生血管的增殖。

METHODS: Totally 60 SD rats aged 7d were randomly divided into 4 groups: normal group, model group, intervention group and NS control group. Normal group was raised in a normal air feeding; model group at 75% high oxygen for 5d to establish the model of oxygen induced retinopathy; intervention group was given anti p16 methylation drug 5-aza-CdR(0.25 mg/kg)intraperitoneal injection; NS control group was given the same volume NS intraperitoneal injection. The eyes were taken from each group and the left eyes were removed for observation of retinal neovascularization by HE staining, and immunohistochemistry and immunofluorescence were taken for observations of p16 protein expression. Right retina had been performed real time-PCR to analysis p16mRNA expression.

RESULTS: The normal group were not found retinal neovascularization breaking through internal limiting mebrane. In model group and NS control group, the retinal tissue was obviously thickened, and a large number of new blood vessels were found. In the intervention group, a small amount of new blood vessels were found in the retina. The expression of p16 was low in the model group, the positive cell number was 19.52±2.67, and the number of the positive cells was 36.38±3.16 in the intervention group, the difference was statistically significant(P<0.001). Real time-PCR showed decreased expression of p16 mRNA in the model group(2^-△△ct=0.14±0.01), the expression of p16 mRNA in the intervention group rats retina was significantly higher than that of NS control group rat retina, there was significant difference between two groups(2^-△△ct=0.68±0.08, P<0.001).

CONCLUSION: The abnormal expression of P16 may be closely related to the proliferation of retinal neovascularization. Inhibition of p16 methylation can decrease the proliferation of retinal neovascularization.