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Melanin, retinal

Melanins are prodnced in mammals in two types of cells of different developmental origin (1) the melanocytes of the skin, hair, choroids and iris and (2) the retinal pigment epithelium (RPE). Specialized organelles of the melanocytes, the melano-somes, synthesize and store eumelanins and phaeomelanins. [Pg.114]

Seagle, B.L. et al., Melanin photoprotection in the human retinal pigment epithelium and its correlation with light-induced cell apoptosis, Proc. Natl. Acad. Sci. USA, 102, 8978, 2005. [Pg.122]

Wang, Z., Dillon, J., and Gaillard, E. R., Antioxidant properties of melanin in retinal pigment epithelial cells, Photochem. PhotobioL, 82, 474, 2006. [Pg.123]

K. Akeo, S. Amaki, T. Suzuki, and T. Hiramitsu, Melanin granules prevent the cytotoxic effects of L-DOPA on retinal pigment epithelial cells in vitro by regulation of NO and superoxide radicals. Pigm. Cell. Res. 13, 80-88 (2000). [Pg.50]

Eye. Several drugs have an affinity for the retinal pigment melanin and thus may accumulate in the eye. Chlorpromazine and other phe-nothiazines bind to melanin and accumulate in the uveal tract, where they may cause retino-toxicity. Chloroquine concentration in the eye can be approximately 100 times that found in the liver. [Pg.30]

Because of cataract development and lenticular changes in animals, baseline and periodic eye exams are recommended in the product labeling for patients receiving quetiapine. However, clinical experience with quetiapine since marketing has not supported a significant risk of cataracts. Retinitis pigmentosa can result from use of thioridazine doses greater than 800 mg daily. It is caused by melanin deposits, and can result in permanent visual impairment or blindness. There is no evidence that it is a function of cumulative dose. ... [Pg.1226]

Dayhaw-Barker, P. (2002) Retinal pigment epithelium melanin and ocular toxicity, Int. J. Tox., 21, 451 154. [Pg.250]

Docchio, F., Boulton, M., Cubeddu, R., Ramponi, R., and Dayhaw-Barker, P. (1991) Age-related changes in the flourescence of melanin and lipofuscin granules of the retinal pigment epithelium a time-resolved fluorescence spectroscopy study, Photochem. [Pg.251]

The mechanism of action of the immunological and anti-inflammatory effects of antimalarials include inhibition of phospholipase A, inhibition of platelet aggregation, a range of lysosomal effects (e.g., an increase in pH, membrane stabilization, and inhibition of release and activity of lysosomal enzymes), inhibition of phagocytosis, an increase in intracellular pH in cytoplasmic vacuoles leading to decreased stimulation of autoimmune CD4 T cells, decreased cytokine release from lymphocytes and stimulated monocytes, inhibition of immune complex formation, and antioxidant activity. In patients with porphyria cutanea tarda, chloroquine and hydroxychloroquine bind to porphyrins and/or iron to facilitate their hepatic clearance. The ability to bind to melanin and other pigments may contribute to the retinal toxicity seen occasionally when anti-malarial agents are used. [Pg.1085]

Glickman, R.D., 1998. Mechanisms of Photooxidative Stress in Retinal Pigment Epithelium Is Melanin a Photosensitizer Technical Report ADA384222, DTIC Online, Defense Technical Information Center, Ft. Belvoir, VA, USA. [Pg.144]

Both phototoxic and photoallergic reactions occurred in patients receiving low doses of chlorpromazine and several other phenothiazine tranquillizers (Zelickson and Zeller 1964). High dosage and prolonged treatment can produce severe dermatitis that is frequently accompanied by darkening of the skin due to the deposition of melanin in lower layers of the dermis. Such patients may also suffer retinal damage, ocular opacity, and loss of vision. [Pg.110]

An intravitreal injection of 200 J4g sisomidn, which is also an aminoglycoside, irreversibly abolished the c-wave. The light rise, the hyperosmolarity response, the VEP and the retinal structure were severely damaged by 200 sisomidn. The responses related to the RPE, such as the c-wave, should be examined in studying toxic effects of chemicals with high melanin-affinity such as aminoglycosides. [Pg.30]

In the present study, we examined ocular toxicity of ofloxacin ophthalmic solution (3 times daily for one year application) in beagle dogs with pigmented eyes. In order to investigate the effects of melanin-bound ofloxacin on retinal function and the effect of ofloxacin on central nerve system, electroretinogram (ERG) was recorded and behavior of dogs was observed during test periods. [Pg.167]

Use is contraindicated in kidney disorders and irritated digestive conditions. Crude drug preparations may induce nausea and vomiting (escop 3). Ingestion of uva ursi for three years resulted in reduced visual acuity and retinal toxicity (bull s-eye maculopathy) in a 56-year-old woman possibly due to inhibition of melanin synthesis. ... [Pg.610]


See other pages where Melanin, retinal is mentioned: [Pg.151]    [Pg.81]    [Pg.81]    [Pg.82]    [Pg.92]    [Pg.808]    [Pg.614]    [Pg.303]    [Pg.484]    [Pg.98]    [Pg.155]    [Pg.618]    [Pg.702]    [Pg.727]    [Pg.54]    [Pg.724]    [Pg.290]    [Pg.275]    [Pg.1098]    [Pg.118]    [Pg.60]    [Pg.60]    [Pg.60]    [Pg.202]    [Pg.497]    [Pg.3949]    [Pg.325]    [Pg.71]    [Pg.163]    [Pg.18]    [Pg.29]    [Pg.351]    [Pg.125]   
See also in sourсe #XX -- [ Pg.131 ]

See also in sourсe #XX -- [ Pg.131 ]




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Melanin

Melanine

Retin

Retinal

Retinitis

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