| 目的：探讨外源性视黄酸对小鸡后极部巩膜基质MMP-2表达的作用。方法：新孵化来亨鸡90只随机分为三组，实验组右眼球后注射RA，隔日一次；左眼为自身对照；阴性对照组右眼球后注射生理盐水；正常对照组不做任何处理。于4、8、14天时各组取10只测量眼轴和屈光度后摘取眼球，采用一步法逆转录－多聚酶链反应（RT-PCR法）检测每组小鸡后极部巩膜MMP-2与TIMP-2 mRNA表达水平。结果：正常组与阴性对照组眼轴及屈光度均有增加，后极部巩膜MMP-2均有表达，实验组眼轴明显延长，屈光度增加，后极部巩膜MMP-2 mRNA表达明显增高，组间差异有显著性（P﹤0.01）。注射后随时间延长眼轴及屈光度逐渐增加，不同时间组间差异显著（P﹤0.01），MMP-2 mRNA表达上调，不同时间组间差异无显著性（P>0.05）。而TIMP-2 mRNA表达与之相反。自身对照组眼轴及屈光度均有增加， MMP-2 mRNA表达较同龄正常对照组有轻度上调，TIMP-2有下调，组间差异显著（P﹤0.01）。结论： 外源性视黄酸能够调节巩膜MMP-2/TIMP-2的转录，并可能通过这一途径促进眼轴及屈光度的增加。
关键词 视黄酸，眼轴，屈光度，基质金属蛋白酶2 ，巩膜重塑
Abstract Objective： To investigate the influence of ectogenesis retinoic acid(RA) to the elongation and remodeling in chick eye. Method: Ninety 1-day-old white leghorn chicks were divided randomly and equivalently into 3 groups. RA retrobulbar injection each two days to the right eye induced the experimental group, the left eye served as self-control group. Saline retrobulbar injection to the right eye induced the negative control group, and normal control group had no treatment. Eyesight and axis oculi in both eyes were measured of 1/3 of each group in 4,8 and 14 days after first injection. Both eyes were collected after the measurement and total RNA in the posterior sclera was extracted traditionally and expression levels of MMP-2 and TIMP-2 mRNA were analyzed by single step reverse transcription-polymerase chain reaction (RT-PCR). Results Compared with normal and negative controlled groups, RA injection made significantly elongation of axis oculi and development of eyesight, as well as a higher level of MMP-2 mRNA expression in the posterior sclera. However, TIMP-2 mRNA expression was just contrary to that of MMP-2. There was statistical differency between normal and self-controlled groups (P<0.01), seemed as the RA injected effected by topediffusion. Conclusion Retinoic acid can manipulate the level of MMP-2 and TIMP-2 mRNA expression in the posterior sclera，and raise the elongation of axis oculi and development of eyesight as well. It may be an important factor in manipulation of eye elongation.
Key words Retinoic Acid; Axis oculi; Eyesight; Matrix metalloproteinase-2；Tissue inhibitor of matrix metalloproteinase-2； Remodeling of Sclera |
