血管内皮生长因子-A_(165)对形觉剥夺性近视豚鼠视网膜中多巴胺水平的影响

Effects of vascular endothelial growth factor-A_(165)on the dopamine level in the retina of guinea pigs with form-deprivation myopia

目的研究玻璃体内注射血管内皮生长因子-A_(165)(VEGF-A_(165))对形觉剥夺性近视(FDM)豚鼠视网膜中多巴胺(DA)水平的影响。方法选取健康3周龄三色豚鼠90只,随机分为6组,分别为空白组、FDM组、PBS组、10 ng组、5 ng组、1 ng组,每组15只。空白组豚鼠双眼不做任何处理,其他组豚鼠用半透明乳胶气球套头连续遮盖右眼14 d建立FDM模型,左眼不做处理。PBS组、10 ng组、5 ng组、1 ng组豚鼠于遮盖前右眼玻璃体内分别注射PBS缓冲液和10 ng、5 ng、1 ng VEGF-A_(165)。在造模前1 d和造模后14 d测量豚鼠右眼屈光度和眼轴长度。造模后14 d,采用免疫荧光法检测各组豚鼠视网膜中酪氨酸羟化酶(TH)阳性细胞数,高效液相色谱法测定DA、DOPAC的含量及DA代谢率,HE染色观察视网膜中血管内皮细胞核数。结果造模前,6组豚鼠右眼屈光度和眼轴长度差异均无统计学意义(均为P>0.05)。造模后14 d,与空白组相比,FDM组豚鼠近视度数升高,眼轴长度增加,TH阳性细胞数降低,DA、DOPAC含量降低,差异均有统计学意义(均为P<0.05);与FDM组相比,10 ng组、5 ng组、1 ng组豚鼠右眼近视度数均降低,眼轴长度均变短,TH阳性细胞数均增加,DA、DOPAC含量均增多,血管内皮细胞核数均增加,其中5 ng组豚鼠近视度数及眼轴长度均低于10 ng组,TH阳性细胞数及DA、DOPAC含量均高于10 ng组,1 ng组豚鼠近视度数及眼轴长度均低于5 ng组,TH阳性细胞数及DA、DOPAC含量均高于5 ng组,差异均有统计学意义(均为P<0.05);10 ng组豚鼠视网膜血管内皮细胞核数最多,5 ng组次之,1 ng组较少,但与空白组相比差异均有统计学意义(均为P<0.05);6组豚鼠间视网膜DA代谢率差异无统计学意义(P=0.574)。结论玻璃体内注射VEGF-A_(165)可以使FDM豚鼠视网膜中DA含量升高,从而抑制豚鼠近视的发展。

Objective To investigate the effects of intravitreal injection of vascular endothelial growth factor-A_(165)(VEGF-A_(165))on the dopamine(DA)level in the retina of guinea pigs with form-deprivation myopia(FDM).Methods A total of 90 healthy 3-week-old tricolor guinea pigs were selected and randomly divided into 6 groups,namely blank group,FDM group,PBS group,10 ng group,5 ng group,and 1 ng group,with 15 guinea pigs in each group.Guinea pigs in the blank group did not receive any treatment on both eyes,while the right eyes of guinea pigs in the remaining five groups were covered by translucent latex balloons for 14 days to establish FDM models,with the left eyes untreated.Guinea pigs in the PBS,10 ng,5 ng,and 1 ng groups were intravitreally injected with PBS buffer,10 ng,5 ng,and 1 ng VEGF-A_(165),respectively,in the right eyes before covering.The refractive power and axial length(AL)of the right eyes were measured 1 day before and 14 days after modeling.Fourteen days after modeling,the number of tyrosine hydroxylase(TH)-positive cells in the retina was found by immunofluorescence.The content of DA and 3,4-dihydroxyphenylacetic acid(DOPAC)and the DA metabolism rate were measured by high-performance liquid chromatography.The number of retinal vascular endothelial cell nuclei was observed by hematoxylin-eosin staining.Results Before modeling,there were no significant differences in the refractive power and AL of the right eyes among the six groups(all P>0.05).Fourteen days after modeling,compared with the blank group,the refractive power and AL of the right eyes in the FDM group increased,while the number of TH-positive cells and the content of DA and DOPAC decreased,and the differences were statistically significant(all P<0.05).Compared with the FDM group,the refractive power and AL of the right eyes in the 10 ng,5 ng and 1 ng groups decreased,while the number of TH-positive cells,the number of vascular endothelial cell nuclei,and the content of DA and DOPAC increased(all P<0.05).The refractive power and AL in the 5 ng group were lower than those in the 10 ng group,while the number of TH-positive cells and the content of DA and DOPAC were higher than those in the 10 ng group;the refractive power and AL in the 1 ng group were lower than those in the 5 ng group,while the number of TH-positive cells and the content of DA and DOPAC were higher than those in the 5 ng group(all P<0.05).The 10 ng group had the most vascular endothelial cell nuclei,followed by the 5 ng group and then the 1 ng group,and the differences were statistically significant compared with the blank group(all P<0.05).There was no significant difference in the DA metabolism rate among the 6 groups(P=0.574).Conclusion Intravitreal injection of VEGF-A_(165)can increase the level of DA in the retina of FDM guinea pigs,thereby inhibiting the development of myopia.