Research on retinoic acid system in retina of guinea pig eyes with form deprivation myopia / 眼科研究

ABSTRACT

Objective Development of eyeball is visually regulated by messengers that released from the retina, and research demonstrated that retinoic acid (RA) is the only extrinsic biochemical candidate that could act as a growth controller. Present study was designed to evaluate the RA system in retina of guinea pig eye with experimental form deprivation myopia. Methods The form deprivation myopia models were monocularly established in the 24 2-week-old guinea pigs by occluding the lateral eyes using white translucent hemispheres for two weeks, and the fellow eyes were as normal control. Refraction diopter was detected with streak retinoscopy after cycloplegia, and axial length and vitreous depth were calculated with Cinescan A/B ultrasonography before and 2 weeks after experiment. All animals were sacrificed and retina was dissected 2 weeks after experiment. The RA level in retina was delected by High Performance Liquid Chromatography (HPLC). The expressions of RA-binding proteins Ⅰ(CRABP-Ⅰ) and RA receptor-β(RAR-β) protein and mRNA were assayed by Western-blotting and Real-time PCR, respectively. The experiment and use of animals followed the Standard of Association for Research in Vision and Ophthalmology. Results The spherical equivalent refraction was (+ 3. 00 ± 0. 75) D in the model group and (+ 2. 88 ± 0. 67) D in control eyes (t= 0. 672, P ＞ 0. 05), the ocular axial length was (7. 822 ± 0. 083) mm in model group and (7. 791 ±0.073) mm in control eyes before experiment (t = 0. 346, P ＞ 0. 05). In 2 weeks after experiment, the spherical equivalent refraction was (- 3. 82 ± 0. 13) D versus (1. 99 ± 0. 58) D and axial length was (8. 346 ± 0. 047) mm versus (7. 888 ± 0. 042) mm between model eyes and control eyes (t = 8. 376, P ＜ 0. 001; t = 3. 343, P ＜0. 05). No significant difference in the level of RA in retina before and after experiment (1. 394 ±0. 079 μg/g vs 1. 295 ±0. 023 μg/g) (t =0. 897, P ＞0. 05) but obviously elevated after experiment in model eyes compared with control eyes (2. 356 ± 0.098 μg/g vs 1.499 ±0.035 μg/g) (t =4. 934, P ＜0. 01). The expression of CRABP-Ⅰ and RAR-β mirrored these directional changes. Conclusion The RA system in retina is upregulated in the eye of guinea pig with form deprivation myopia. This findings suggests that RA may act as a messenger in the development of experimental myopia.