Circadian rhythms in the eye: The physiological significance of melatonin receptors in ocular tissues

Wiechmann, Allan F.; Summers, Jody A.

doi:10.1016/j.preteyeres.2007.10.001

Cited by 110 publications

(89 citation statements)

References 190 publications

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“…A role for melatonin in protecting against the development of glaucoma and in lowering the intraocular pressure has been also proposed (10)(11). Indeed, our data showing that in C3H/f ϩ/ ϩMT1 Ϫ/Ϫ mice have a significant reduction in the number of ganglion cells (Figs.…”

Section: Discussionsupporting

confidence: 56%

Melatonin modulates visual function and cell viability in the mouse retina via the MT1 melatonin receptor

Baba

Pozdeyev²,

Mazzoni³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

111

165

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A clear demonstration of the role of melatonin and its receptors in specific retinal functions is lacking. The present study investigated the distribution of MT1 receptors within the retina, and the scotopic and photopic electroretinograms (ERG) and retinal morphology in wildtype (WT) and MT1 receptor-deficient mice. MT1 receptor transcripts were localized in photoreceptor cells and in some inner retinal neurons. A diurnal rhythm in the dark-adapted ERG responses was observed in WT mice, with higher a-and b-wave amplitudes at night, but this rhythm was absent in mice lacking MT1 receptors. Injection of melatonin during the day decreased the scotopic response threshold and the amplitude of the a-and b-waves in the WT mice, but not in the MT1 ؊/؊ mice. The effects of MT1 receptor deficiency on retinal morphology was investigated at three different ages (3, 12, and 18 months). No differences between MT1 ؊/؊ and WT mice were observed at 3 months of age, whereas at 12 months MT1 ؊/؊ mice have a significant reduction in the number of photoreceptor nuclei in the outer nuclear layer compared with WT controls. No differences were observed in the number of cells in inner nuclear layer or in ganglion cells at 12 months of age. At 18 months, the loss of photoreceptor nuclei in the outer nuclear layer was further accentuated and the number of ganglion cells was also significantly lower than that of controls. These data demonstrate the functional significance of melatonin and MT1 receptors in the mammalian retina and create the basis for future studies on the therapeutic use of melatonin in retinal degeneration.electroretinogram ͉ neuroprotection ͉ visual sensitivity ͉ glaucoma

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Section: Discussionsupporting

confidence: 56%

Melatonin modulates visual function and cell viability in the mouse retina via the MT1 melatonin receptor

Baba

Pozdeyev²,

Mazzoni³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

111

165

View full text Add to dashboard Cite

show abstract

“…8 The indole melatonin (N-acetyl-5-methoxytryptoamine) is a neurohormone that has crucial roles in the regulation of many physiological events. 9 It is a highly lipophilic molecule that can easily pass through the cell membranes and reach subcellular compartments. 10 Production of ocular melatonin is initiated by photoreceptors in the retina.…”

Section: Introductionmentioning

confidence: 99%

Melatonin and amfenac modulate calcium entry, apoptosis, and oxidative stress in ARPE-19 cell culture exposed to blue light irradiation (405 nm)

Argun

Tök

Uğuz

et al. 2014

Eye

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“…[29] Several studies have shown that melatonin is produced not only in the pineal gland but also in ocular tissues, specifically the retina, ciliary epithelial cells, and lens cells. [34] Furthermore, the rhythms that control melatonin synthesis and release in the retina are entrained by light, are temperature compensated, and have been shown to persist both in vivo and in vitro. [35] Melatonin also appears to entrain the biological clock via activation of G-protein coupled integral membrane melatonin receptors, which have been identified in several ocular tissues, such as the neural retina, ciliary body, cornea, and lens.…”

Section: Environmental Effects On Melatonin Productionmentioning

confidence: 99%

“…[35] Melatonin also appears to entrain the biological clock via activation of G-protein coupled integral membrane melatonin receptors, which have been identified in several ocular tissues, such as the neural retina, ciliary body, cornea, and lens. [34] In humans, the action spectra for melatonin suppression has a maximum around 460 nm suggesting that melanopsin, a functional photopigment, plays a role in the photic regulation of melatonin levels, circadian rhythms, and sleep patterns. [29] Further data shows that blue light with wavelengths between 440-480 nm is highly effective in phase-shifting the human circadian clock and suppressing melatonin secretion.…”

Section: Environmental Effects On Melatonin Productionmentioning

confidence: 99%

The Role of Melatonin in Cancer Development

Liu¹,

Madu²,

Lu³

2018

Oncomedicine

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Melatonin is a hormone that is secreted by the pineal gland in the brain. Its secretion during periods of darkness represents a 24-hour rhythm controlled by the circadian clock and is pivotal in the regulation of sleep and wake cycles. Although circadian rhythms are endogenous processes, they can be affected by environmental factors such as light and temperature. In addition to its role in circadian rhythms, melatonin has also been observed to function in the immune system, female menstrual cycles, seasonal behavior, tumor inhibition, and anti-aging processes.[1] Melatonin production increases during the night and decreases in the daytime with exposure to light. Low levels of normal melatonin have been linked to neoplasia, such as the growth of rat hepatomas and human breast cancer xenografts, circadian phase shifts, sleep disturbances, and immunosuppression. [3,4] Furthermore, sleep disturbance, not factoring in melatonin production, can lead to immune suppression and a shift to the predominance in cancer-stimulatory cytokines.[4] To combat cancer, studies have shown that melatonin significantly suppresses cell proliferation and induces apoptosis.[2] There have been no direct links determined between abnormal melatonin production observed in sleep disturbances and cancer, so this review will focus on the experimental evidence depicting the role of melatonin in the prevention of cancer development.

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Circadian rhythms in the eye: The physiological significance of melatonin receptors in ocular tissues

Cited by 110 publications

References 190 publications

Melatonin modulates visual function and cell viability in the mouse retina via the MT1 melatonin receptor

Melatonin modulates visual function and cell viability in the mouse retina via the MT1 melatonin receptor

Melatonin and amfenac modulate calcium entry, apoptosis, and oxidative stress in ARPE-19 cell culture exposed to blue light irradiation (405 nm)

The Role of Melatonin in Cancer Development

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