负透镜诱导型近视豚鼠视网膜中谷氨酸及其受体的表达

目的　观察谷氨酸及其离子型受体Ｎ-甲基-Ｄ-天冬氨酸受体（Ｎ-ｍｅｔｈｙｌ-Ｄ-ａｓｐａｒｔａｔｅｒｅｃｅｐｔｏｒ，ＮＭＤＡＲ）功能亚单位ＮＲ２Ａ在近视豚鼠视网膜上的动态表达，探讨其在近视发病过程中的作用。方法　选取３周龄健康三色短毛豚鼠１２０只，采用随机数字表法分为０周正常组、２周正常组、２周近视组、４周正常组、４周近视组，每组２４只；正常组不作任何干预，近视组右眼均戴－１０Ｄ透镜，左眼不戴镜作为对照。入组前与处死前均进行屈光度及眼轴长度检测，腹腔注射过量水合氯醛处死，并分离视网膜，采用高效液相色谱分析检测视网膜中谷氨酸的含量变化，实时荧光定量ＰＣＲ以及ＥＬＩＳＡ分别检测豚鼠视网膜中ＮＲ２ＡｍＲＮＡ及其蛋白水平的表达变化。结果　造模前各组屈光度及眼轴长度差异均无统计学意义（均为Ｐ＞０．０５）。造模后各组与造模前比较，眼轴长度及屈光度差异均有统计学意义（２周正常组Ｐ＜０．０５，２周近视组Ｐ＜０．００５，４周正常组Ｐ＜０．０１，４周近视组Ｐ＜０．００１）。造模后，正常组间眼轴长度和屈光度比较差异均有统计学意义（Ｆ＝２０．３２，Ｐ＜０．０１；Ｆ＝１９９．６５，Ｐ＜０．０１）；２周近视组与４周近视组比较，右眼眼轴长度和屈光度差异均有统计学意义（Ｆ＝７８．９６，Ｐ＜０．００１；Ｆ＝２５２．１０，Ｐ＜０．００１），左眼眼轴长度和屈光度差异均无统计学意义（Ｆ＝１３．６６，Ｐ＞０．０５；Ｆ＝２１．２０，Ｐ＞０．０５）；２周近视组与４周近视组右眼分别与相应的左眼比较，眼轴长度差异均有统计学意义（２周近视组:ｔ＝９．５１５，Ｐ＜０．００５；４周近视组:ｔ＝９．４４９，Ｐ＜０．００１），屈光度差异同样均有统计学意义（２周近视组:ｔ＝８．８９７，Ｐ＜０．００１；４周近视组:ｔ＝１７．２３５，Ｐ＜０．００１）。视网膜中谷氨酸含量正常组之间差异均无统计学意义（均为Ｐ＞０．０５）；造模后２周近视组与４周近视组比较，右眼视网膜中谷氨酸含量逐渐增加，差异有统计学意义（ｔ＝３６．２３０，Ｐ＜０．０１）。造模后２周近视组较２周正常组右眼谷氨酸含量增加，差异有统计学意义（ｔ＝－２３．２４０，Ｐ＜０．０５）；同样４周近视组较４周正常组右眼谷氨酸含量亦增加，差异亦有统计学意义（ｔ＝－５３．６９０，Ｐ＜０．０１）。视网膜中ＮＲ２ＡｍＲＮＡ的表达量，正常组之间差异均无统计学意义（均为Ｐ＞０．０５）。造模后４周近视组与２周近视组比较，右眼视网膜ＮＲ２ＡｍＲＮＡ表达量明显上调，差异有统计学意义（ｔ＝５５．６６０，Ｐ＜０．００１）；２周近视组与２周正常组右眼比较表达量增加，差异有统计学意义（ｔ＝－１５．０８６，Ｐ＜０．００５），同样４周近视组与４周正常组右眼比较差异亦有统计学意义（ｔ＝－４３．２７６，Ｐ＜０．００１）。正常组之间视网膜中ＮＲ２Ａ蛋白表达量，差异无统计学意义（均为Ｐ＞０．０５）。４周近视组与２周近视组比较，右眼视网膜ＮＲ２Ａ蛋白表达量明显上调，差异有统计学意义（ｔ＝４３．２１０，Ｐ＜０．００５）；２周近视组与２周正常组右眼比较ＮＲ２Ａ蛋白表达量增加，差异有统计学意义（ｔ＝－２．３６５，Ｐ＜０．０５），同样４周近视组与４周正常组右眼比较差异亦有统计学意义（ｔ＝－５．５１８，Ｐ＜０．０１）。结论负透镜诱导型近视豚鼠视网膜中谷氨酸及其ＮＭＤＡＲ受体亚单位ＮＲ２Ａ在透镜诱导眼中表达上调，并随透镜诱导时间的延长和近视程度的加深而增加。

Expression of glutamate and its receptor in retina of lens-induced myopia guinea pigs

Objective To observe the dynamic expression of glutamate and its ionotropic receptors, N methyl D aspartic acid receptor ( NMDAR) subunits NR2A in guinea pigs’ retina, and explore its role in the pathogenesis of myopia. Methods A total of 120 three week-old healthy guinea pigs were randomly divided int0 0 week normal group ,2 weeks normal group ,2 weeks myopia group ,4 weeks normal group and 4 weeks myopia group,24 cases in each group, the both eyes of normal groups was not treated.while the right eyes of the myopia group were wearing - 10 D lens and the fellow eyes was not treated as control. The refraction and axial length were measured in all groups at the beginning and before death. The guinea pigs were sacrificed in the end of experiment.and the retina were isolated. HPLC technique was used to measure the expression of glutamate in retina. The expressions of NR2A in retina were assayed by real-time PCR , ELISA. Results Before the expemnent ,there was no significant difference in the diopter and axial length of the eyes (P > 0. 05 ) . After modeling , each groups of the axial length and diopter compared with before had statistical difference (P < 0. 05 in 2 weeks normal group ,P <0. 005 in 2 weeks myopia group,P < 0. 01 in 4 weeks normal group,P < 0. 001 in 4 weeks myopia group) . Comparison between the 2 weeks normal group and 4 weeks normal group, the difference was statistically sigruficant in the axial length and diopter( F = 20. 32 .P < 0. 01 ;F = 199. 65 ,P < 0. 01 ) . The difference of the diopter and axial length of right eyes between 2 weeks myopia group and 4 weeks myopia group were statistically significant ( F = 78. 96 .P < 0. 001 ;F = 252. 10 .P < 0. 001 ) , and the difference of the left eye was not obvious statistically significant ( F = 13. 66 , P > 0. 05 ;F = 21. 20 .P > 0. 05 ). There were statistical differences in the axial length of 2 weeks myopia group and 4 weeks myopia group between left eyes and right eyes (2 weeks myopia group : t = 9. 515 ,P < 0. 005 ;4 weeks myopia group : t = 9. 449 ,P < 0. 001 ) . and there were also statistical differences in the diopter (2 weeks myopia group : t = 8. 897 .P < 0. 001 ;4 weeks myopia group : t = 17. 235 .P < 0. 001 ) . The result of the HPLC showed that the expression of retinal glutamate between each normal group was not statistically significant ( all P > 0. 05 ) . The content of glutamate in the retina of the right eyes were gradually increased . and the difference was statistically significant between 2 weeks myopia group and 4 weeks myopia group ( t = 36. 230 ,P < 0. 01 ) . Comparing with the normal groups ,the difference with the right eyes of the myopia groups also have statistical significance (2 weeks group : t = - 23. 240 .P < 0. 05 ;4 weeks group : t = - 53. 690 . P < 0. 01) . The result of the PCR showed that the expression of NR2A mRNA between the normal group was not statistical sigruficant ( all P > 0. 05 ) . The content of the NR2A mRNA in the retinal of right eye were gradually increased . and the difference was statistically significant between 2 weeks myopia group and 4 weeks myopia group ( t = 55. 660 ,P < 0. 001 ) . Comparing with the normal groups, the difference of the right eyes in the myopia groups also had statistical significance ( t = - 15. 086.P < 0. 005 ; t = -43. 276 ,P < 0. 001 ) . The results of the ELISA showed that the protein expression of NR2A between each normal group was not statistically sigruficant ( all P > 0. 05 ) . The content of the NR2A protein in the retina of the right eye were gradually increased and the difference had statistical significance between 2 weeks myopia group and 4 weeks myopia group ( t = 43. 210 .P < 0. 005 ) . Comparing with the normal groups , the difference