Effect of light pattern on dopamine transporter in the guinea pig retina

Authors: Wang Jingjing,  Li Kai,  Xiang Kaidi,  Chen Jun,  Du Linlin,  Yang Jinliuxing,  Liu Sichen,  Wang Ling,  He Xiangui
DOI: 10.3760/cma.j.cn115989-20231103-00159
Published 2024-04-10
Cite as Chin J Exp Ophthalmol, 2024, 42(4): 309-314.

Abstract                           Download PDF】 【Read Full Text

Objective

To study the distribution and changes of dopamine transporter (DAT) in guinea pig eyes under different light patterns.

Methods

Thirty-six 3-week-old white ordinary-grade guinea pigs were randomly selected and divided into groups of 10 000 lx, 5 000 lx, and 500 lx, with 12 guinea pigs in each group exposed to strong light, medium strong light, and normal light, respectively.Each group was randomly divided into 3 subgroups, with 4 guinea pigs in each subgroup.The 3 subgroups of 500 lx group received light exposure for 5, 20, and 40 minutes, respectively.The 3 subgroups of 5 000 lx group received light exposure for 2, 4, and 40 minutes, respectively.The 3 subgroups of 10 000 lx group received light exposure for 2, 5, and 20 minutes, respectively.After light treatment, each group of guinea pigs was injected with 99mTc-TRODAT-1 for SPECT DAT imaging, and image data were collected by Micro-SPECT.The region of interest (ROI) of guinea pig retinas was analyzed using Micro-CT software.The counts of ROI were expressed as Sum, which reflected the relative distribution or density of DAT.The DAT density between experimental and control eyes of guinea pigs after light exposure, the differences in DAT density between guinea pig eyes under different light intensities, the differences in DAT density between guinea pig eyes after different light durations, and the cumulative and interactive effects of light intensity and light duration on DAT aggregation in guinea pigs were compared.Another 3 guinea pigs were selected, and after light exposure, the 3 guinea pigs’ eyes underwent continuous image acquisition for 6 hours at 20-minute intervals, and 18 images per guinea pig were acquired to analyze the trend of DAT density in guinea pig eyes over time.This study was approved by the Ethics Committee of Shanghai General Hospital (No.2020SQ196).

Results

The DAT density (Sum value) of experimental eyes at 500, 5 000, and 10 000 lx were 5 598.97±3 159.38, 8 636.78±2 503.16, and 7 407.39±2 053.41, respectively, significantly higher than 4 388.89±2 902.90, 5 981.92±3 057.44, and 5 091.32±2 039.36 of control eyes (t=5.31, 4.69, 11.80; all at P<0.001). At 500 lx, there was a statistically significant difference in DAT density between the experimental and control eyes of guinea pigs at different light exposure durations (F=14.01, P<0.01), while no significant difference was found at other light intensities at different light exposure durations (both at P>0.05). When the light exposure time was 5 minutes, the difference in DAT density between the experimental and control eyes of guinea pigs was significantly greater in the 10 000 lx group than in the 500 lx group (t=-13.22, P<0.001). There was no statistically significant difference between different groups at other light exposure durations (all at P>0.05). No cumulative or interactive effects of light intensity and light duration were found on the differences in DAT density (all at P>0.05). Continuous scanning after illumination showed that DAT density in guinea pig retinas first increased to a peak over time and then gradually returned to normal values.

Conclusions

Light, even under moderate or normal light levels, can cause an increase in the secretion of DAT in the retina and stimulate the production of DAT.Light intensity and duration have no cumulative or interactive effects on the distribution and density of retinal DAT.

Key words:

Myopia; Light; Guinea pigs; Dopamine transporter

Contributor Information

Wang Jingjing

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

Li Kai

Fudan University School of Public Health, Shanghai 200032, China

Xiang Kaidi

Department of Ophthalmology, Shanghai General Hospital, Shanghai 200080, China

Chen Jun

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

Du Linlin

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

Yang Jinliuxing

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

Liu Sichen

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

Wang Ling

Fudan University School of Public Health, Shanghai 200032, China

He Xiangui

Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, National Clinical Research Center for Eye Diseases, Shanghai Vision Health Center &

Shanghai Children Myopia Institute, Shanghai 200040, China

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