Effects of blue light spectra on retinal stress and damage in goldfish (Carassius auratus)
There have been a number of studies on the negative effects of blue light exposure in various species; however, little information is available on the impacts of blue light intensity and duration on fish. We investigated the effects of blue light spectra on stress in the retinas of goldfish, using a blue (460 nm) light-emitting diode (LED) at three intensities (0.5, 1.0, and 1.5 W/m2). The experiment was conducted for 4 weeks, and sampling was performed at intervals of 1 week. We measured changes in the expression of cortisol, and the concentrations of hydrogen peroxide (H2O2), melanin-concentrating hormone receptor (MCH-R), and caspase-3 in the retinas of goldfish. In addition, we measured histological changes in the retina. We used a transferase dUTP nick end labeling (TUNEL) assay to evaluate the apoptotic response to blue LED spectra. Levels of cortisol, H2O2, MCH-R, and caspase-3 increased with exposure time and light intensity. Histological analysis revealed that the thickness of melanin granules increased with exposure time and light intensity. The progressive TUNEL assay revealed many apoptotic cells after exposure to blue LED light, increasing with exposure time and light intensity. Irradiation with blue light for longer than 1 week induced increased retinal stress and may induce apoptosis in the retinas of goldfish, even at a low intensity.
KeywordsBlue light Carassius auratus Cortisol Retinal damage Stress
This research was supported by the project titled “Development and commercialization of high density low temperature plasma based seawater sterilization pulification system” funded by the Ministry of Oceans and Fisheries, Republic of Korea.
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