|
|
|
| Contributions of Sleep Deprivation to the Development of Lens-Induced Myopia and Retinal Dopamine Metabolism in Guinea Pigs |
| Xueli Yang, Yao Chen, Yuxin Guan, Chaoqun Yuan, Junfeng Mao |
| Ophthalmology Center, Xiangya Hospital, Central South University, Hunan Provincial Key Laboratory of Ophthalmology, Changsha 410008, China |
|
|
|
| Guide |
|
|
Abstract Objective: To investigate the effects of sleep deprivation (SD) on the development of lens-induced myopia (LIM) and the dopamine (DA) metabolism in guinea pigs. Methods: This was an animal experimental study. A total of 30 three-week-old guinea pigs supplied were randomly divided into two groups: LIM group and LIM+SD group, raised either in a normal sleep environment or subjected to sleep deprivation for 20 hours every day. Refraction, corneal curvature radius, and ocular axial components were measured. The content of DAand 3, 4-dihydroxyphenylacetic acid (DOPAC) in the retina was assessed by the high-performance liquid chromatography electrochemical method, and the DOPAC/DA ratio was calculated. The expression of retinal tyrosine hydroxylase (TH) protein was evaluated by immunohistochemical staining and Western blot. Paired t-test was used to compare the refraction and DAturnover between the left and right eyes of guinea pigs. Independent sample t-test was used for comparison between the LIM group and the LIM+SD group. The refractive error and axial length of the guinea pig eyes in the defocus eyes underwent a correlation analysis with DA content by using Pearson correlation analysis. Results: Normal refractive development was not affected by SD in guinea pigs. However, SD signifcantly deepened myopia and prolonged the ocular axis of defocus eyes (t=5.63, P<0.001; t=-3.87, P=0.001). The content of retinal DAand DOPAC in all defocus eyes was lower than that in their control eyes (LIM group: t=-8.64, P<0.001; t=-13.03, P<0.001; LIM+SD group: t=-11.72, P<0.001; t=-16.32, P<0.001). Compared with LIM group, the defocus eyes of LIM+SD group had lower DAand DOPAC obviously (t=5.35, P<0.001; t=3.80, P=0.002), while the DOPAC/DA ratio increased and the difference was statistically signifcant (t=-3.60, P=0.003). The content of retinal DAin defocus eyes was correlated with refractive error (r=0.93, P<0.001) and eye axis length (r=-0.77, P=0.001). Retinal immunohistochemical staining showed that TH positive cells were mainly distributed in the nerve fber layer, ganglion cell layer, inner plexiform layer, and inner nuclear layer, and had a minor portion in outer plexiform layer. The expression of TH protein in defocus eyes was reduced compared with control eyes. Western blot showed that the expression of TH protein in defocus eyes was signifcantly lower than control eyes (LIM group: t=-40.25, P<0.001; LIM+SD group: t=-17.64, P<0.001). But the retinal TH protein expression had no significant difference in the defocus eyes between the LIM and LIM+SD groups (P>0.05). Conclusions: SD had no signifcant effects on normal refractive development. However, in a lens-induced environment, SD promotes the development of LIM in guinea pigs probably by accelerating DAcatabolism without affecting DAanabolism.
|
|
Received: 13 October 2022
|
|
|
| Fund:Natural Science Foundation of Hunan Province (2021JJ31088) |
|
Corresponding Authors:
Junfeng Mao, Email: mao_junfeng@163.com
|
|
|
|
|
|
|
