电针对负透镜诱导型近视豚鼠视网膜M1受体表达的影响

目的　探讨电针对负透镜诱导型近视豚鼠视网膜中毒蕈碱样乙酰胆碱Ｍ１受体表达的影响。方法　４８只３周龄豚鼠随机分为４组:正常对照组、近视模型组、近视电针组与近视假穴组，后３组豚鼠右眼配戴－１０．００Ｄ透镜片，建立透镜诱导型近视豚鼠动物模型，近视电针组戴镜同时给予针刺豚鼠的合谷穴和太阳穴，近视假穴组针刺臀部无穴位处。于造模前及造模后４周测量各组眼轴长度和屈光度，同时取视网膜组织，利用ＲＴ-ＰＣＲ的方法检测各组豚鼠视网膜中Ｍ１受体ｍＲＮＡ的相对表达量，ＥＬＩＳＡ法检测Ｍ１受体的蛋白含量。结果　造模４周后，近视模型组右眼屈光度为（－３．４０±０．５５）Ｄ，明显低于正常对照组右眼的（１．２０±０．２４）Ｄ和自身对照眼左眼的屈光度（１．２５±０．３２）Ｄ（均为Ｐ＜０．０５）；近视模型组右眼眼轴长度为（８．７４±０．３８）ｍｍ，明显大于正常对照组的右眼眼轴长度（８．２３±０．２１）ｍｍ，也大于自身对照眼左眼的眼轴长度（８．１６±０．４３）ｍｍ（均为Ｐ＜０．０５）；近视模型组、近视电针组和近视假穴组右眼的眼轴长度和屈光度比较差异均无统计学意义（均为Ｐ＞０．０５）。正常对照组、近视模型组、近视电针组、近视假穴组视网膜中Ｍ１受体的ｍＲＮＡ相对表达量分别为５９．１７±４．０２、７４．５０±４．６４、６４．８３±６．０５和７４．６７±３．９３，Ｍ１受体蛋白含量分别为（９８４．６７±４４．６９）ｎｇ·Ｌ－１、（１１７２．００±４１．９１）ｎｇ·Ｌ－１、（１０２７．００±４１．０８）ｎｇ·Ｌ－１和（１１５３．５０±５６．４０）ｎｇ·Ｌ－１，统计学分析显示正常对照组与近视电针组相比差异无统计学意义（Ｐ＞０．０５），两组分别与近视模型组和近视假穴组相比差异均有统计学意义（均为Ｐ＜０．０５）。结论　负透镜诱导型近视豚鼠视网膜中Ｍ１受体表达增高，针刺合谷穴和太阳穴可以减少其视网膜中Ｍ１受体表达，这可能是针刺改善近视患者远视力的机制之一。

Effects of electroacupuncture stimulation on levels of retinal acetylcholine receptors Ml in guinea pig model of lens-induced myopia

Objective To observe the effects of electroacupuncture( EA) stimulation on the levels of retinal acetylcholine receptors Ml ( AchRMI) in guinea pig models of lens-induced myopia ( LIM) . Methods Forty-eight three-week-old healthy guinea pigs were randomized into the normal control group ,myopia model group , myopia + EA group,myopia+ sham acupoint group. The right eyes of guinea pigs in the last three model group was established LIM model by monocularly fitted with - 10. 00 D lens . and the fellow eyes of the model group were used as the self-control eyes. The myopia + EA group were acupunctured at HeGu acupoint and TaiYang acupoint, the myopia + sham group were acupunctured at bottom where there was no acupoint. The refraction and axial length of eyes were measured before and 4 weeks after modeling. The guinea pigs were sacrificed at the fourth week after modeling , and the retinas were isolated. The relative expression levels of subtypes of AchRMI were detected by real-time PCR, and AchRMI content in the retinas were assayed by enzyme linked immunosorbent assay ( ELISA) . Results At the fourth week after modeling , the diopter of model eyes was ( - 3. 40 +0. 55) D, which was significantly higher than ( 1. 20 + 0. 24) D of the normal control eyes and ( 1. 25 +0. 32) D of the self-control eyes in the model group ( both P < 0. 05 ) . The axial length of experimental eyes was ( 8. 74 + 0. 38 ) mm. which was increased in comparison with (8. 23 +0. 21 ) mm of the normal control eyes and ( 8. 16 + 0. 43 ) mm of the self-control eyes in the model group ( both P < 0. 05 ) . The relative expression levels of subtypes of AchRMI mRNA in the retinas were significantly increased in the myopia group , the myopia + acupuncture group , myopia + sham group , which were 74. 50 + 4. 64 ,64. 83 + 6. 05 .74. 67 + 3. 93 , respectively. Compared with the normal control group , which was 59. 17 + 4. 02 . there was statistical difference ( P < 0. 05 ) , it was significantly decreased in the myopia + acupuncture group compared with the myopia group (P < 0. 05 ) , However, no significant difference was seen in the relative expression of AchRMI receptors mRNA between the normal control group and myopia + acupuncture group(P > 0. 05). The AchRMI contents in retina were (984. 67 + 44. 69 ng ’ L-’, ( 1172. 00 +41. 9l)ng . L-l , ( 1027. 00 +41. 08 ) ng . L-l , ( 1153. 50 + 56. 40) ng . L-l in the normal control group , myopia model group , myopia + EA group and myopia + sham acupoint group , respectively ,there was no statistical difference between the normal control group and myopia + acupuncture group ( P > 0. 05 ) , but there were sigruficant differences of above two groups compared with myopia model group, myopia + sham acupoint group ( all P < 0. 05 ) . Conclusion The expressions of AchRMI and mRNA of AchRMI receptor increase in the LIM myopia eyes. EA can lower the level of AchRMI and AchRMI receptor mRNA in retina of LIM eyes , which may be one of mechanisms of acupuncture improving the distant visual acuity for myopia patients.