目的：观察透镜诱导型近视豚鼠脉络膜毛细血管密度的变化，探讨脉络膜内皮素-1(ET-1)、内皮素受体A(ETAR)及受体B(ETBR)的表达变化及电针治疗机制。

方法：将54只豚鼠随机分为正常对照组(NC组)、透镜诱导组(LIM组)和电针+透镜诱导组(LIM+EA组)。NC组正常饲养，不干预； LIM组和LIM+EA组右眼配戴-6.00D透镜片，建立近视模型。造模2、4wk测量各组豚鼠屈光度、眼轴和脉络膜毛细血管密度，实时荧光定量PCR(q-PCR)、酶联免疫吸附试验(ELISA)和免疫组化检测各组脉络膜ET-1、ETAR和ETBR mRNA及蛋白表达水平。

结果：造模2、4wk后，与NC组相比，LIM组和LIM+EA组近视屈光度和眼轴均增加(均P<0.001)； LIM+EA组与LIM组相比，屈光度和眼轴均减小(均P<0.05)。造模2、4wk后，与NC组相比，LIM组脉络膜毛细血管密度均降低(P<0.001)，脉络膜ET-1、ETAR及ETBR mRNA和蛋白水平均增加(均P<0.05)； 而LIM+EA组与LIM组相比，脉络膜毛细血管密度升高(P<0.01)，脉络膜ET-1、ETAR及ETBR mRNA和蛋白水平均降低。

结论：在透镜诱导型近视豚鼠中，随着屈光度和眼轴的增长脉络膜血流减少，而电针可能通过神经调控改善了脉络膜的血流，影响了血管剪切力，下调ET-1及其受体含量以延缓近视的发生发展。

AIM:To observe the changes of the vessel density of choriocapillaris in lens-induced myopia in guinea pigs, and to explore choroidal endothelin-1(ET-1), endothelin receptor A(ETAR)and receptor B(ETBR)expression changes and the effect of electroacupuncture.

METHODS: Fifty-four guinea pigs were randomly divided into normal control(NC), lens-induced myopia(LIM)and LIM+electroacupuncture(LIM+EA). The NC group was fed normally without intervention and the right eye in LIM group and LIM+EA group was coverd with a -6.00D lens to establish a myopia model. At 2 and 4wk, the refraction, axial length and the vessel density of choriocapillaris in groups were measured. The expression and protein content of ET-1, ETAR and ETBR mRNA in groups were detected by the real-time fluorescent quantitative PCR(quantitative polymerase chain reaction, q-PCR), enzyme-linked immunosorbent assay(ELISA)and immunohistochemistry.

RESULTS: At 2 and 4wk, compared with the the NC group, refraction and axial length in LIM group and LIM+EA group had significantly increased(all P<0.001). Compared with the LIM group, the refraction and axial length in LIM+EA group were decreased(all P<0.05). At 2 and 4wk, compared with the NC group,the vessel density of choriocapillaris was decreased(P<0.001)and the ET-1, ETAR and ETBR mRNA and protein levels in choroid were increased(all P<0.05)in LIM group. At 2 and 4wk, compared with the LIM group,the vessel density of choriocapillaris was decreased(P<0.01)and the ET-1, ETAR and ETBR mRNA and protein levels in choroid were increased in LIM+EA group.

CONCLUSION:In LIM guinea pigs, the choroidal blood flow decreased with the increased of refraction and axial length, which may affect ET-1 and its receptors through vascular shear force during the development of myopia. At the same time, electroacupuncture can improve choroidal blood flow through neuromodulation and affects the vascular shear stress to down-regulate the content of ET-1 and its receptor to delay the development of myopia.

山东省自然科学基金(No.ZR2020QH314); 山东省医药科技发展计划项目(No.2019WS570)