AIM: To observe the effect of inlravilreal injection of pirenzepine on form — deprivation myopia in chicks. METHODS: Forty — one day old chicks were randomly divided into 4 groups: normal control group, form deprivation group, vehicle control group and pirenzepine injection group. The right eyes of all chicks were used as experimental eyes. The deprived eyes in vehicle control group and pirenzepine injection group received daily intravitreal injection of vehicle control solution (0.01 mol/L PBS) and pirenzepine (l%in PBS) , respectively. Optical examinations such as refraction, axial length and equatorial diameter were made at the end of the 5 th day. The mRNA and protein levels of matrix met-alloproteinase 2 ( MMP —2) and tissue inhibitor of metalloproteinase —2 (TIMP — 2) , and the activity of MMP —2 were detected by RT — PCR, Western blotting and zymography analysis,respectively. RESULTS: Refraction, axial length and equatorial diameter of the eyes in pirenzepine injection group were significantly lower than those in form deprivation group and vehicle control group ( P < 0. 05 ) , but those were higher ( P < 0. 05 ) and the eyes were relatively myopic as compared with normal control group. The mRNA expression, protein levels and activity of MMP —2 in pirenzepine group were significantly higher than those in normal control group ( P < 0. 01) , and were significantly lower than those in form deprivation group and vehicle control group ( P < 0. 01, P < 0. 01). The mRNA and protein levels of TIMP — 2 in pirenzepine group were significantly lower than those in normal control group ( P < 0. 01) , and was significantly higher than those in form deprivation group and vehicle control group (P <0. 01, P <0. 01). CONCLUSION: Intravitreal injection of pirenzepine may partly pre-vent form — deprivation myopia by modulaling the expression of MMP — 2 and TIMP — 2 in the fibrous layer of solera.%目的:观察玻璃体内注射哌仑西平对鸡眼形觉剥夺性近视的疗效并探讨哌仑西平抑制近视的巩膜机制.方法:1日龄鸡40只,随机分为正常组、单纯遮盖组、药物对照组和哌仑西平组,均以右眼为实验眼.后3组鸡的右眼用半透明眼罩遮盖,后2组鸡的剥夺眼分别每日玻璃体内注射0.01 mol/L的磷酸盐缓冲液和1%哌仑西平磷酸盐缓冲液.5 d后检测4组动物右眼屈光度、眼轴长度和赤道部直径,利用RT-PCR、Western blotting 和明胶酶谱技术检测巩膜纤维层级质金属蛋白酶2(MMP-2)和金属蛋白酶组织抑制剂2(TIMP-2) mRNA和蛋白质的表达及MMP-2活性的改变.结果:哌仑西平治疗组较单纯遮盖组和药物对照组鸡眼屈光度显著减少(P<0.05),眼轴长度和赤道径显著缩短(P<0.05),较正常组呈相对近视,眼轴长度和赤道径显著增加(P<0.05).RT-PCR、Western blotting 和明胶酶谱结果显示:哌仑西平组较单纯遮盖组和药物对照组MMP-2 mRNA和蛋白质的表达及其活性均明显降低 (P<0.01),而较正常组显著升高(P<0.01);哌仑西平组较单纯遮盖组和药物对照组TIMP-2 mRNA和蛋白质的表达均明显增高(P<0.01),而较正常组显著降低(P<0.01).结论:玻璃体内注射哌仑西平能部分抑制近视的发生发展.哌仑西平很可能通过调节巩膜纤维层MMP-2和TIMP-2的表达而部分抑制近视的发生发展.
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