Distribution of melanosomes across the retinal pigment epithelium of a hooded rat: implications for light damage

Journal Article · Mon Feb 01 04:00:00 EST 1982 · Invest. Ophthalmol. Visual Sci.; (United States)

OSTI ID:5513200

Howell, W L; Rapp, L M; Williams, T P

Distribution of melanosomes across the retinal pigment epithelium of hooded rats (Long-Evans) is studied at the light microscopic and electron microscopic levels. This distribution is shown to be nonuniform: more melanosomes exist in the periphery than elsewhere and, importantly, there are very few melanosomes in a restricted area of the central portion of the superior hemisphere compared with the corresponding part of the inferior hemisphere. The region with fewest melanosomes is precisely the one that is highly susceptible to light damage. Because this region is the same in both pigmented and albino eyes, the paucity of melanin in this region is not the cause of its great sensitivity to light damage. Nor does light cause the nonuniform distribution of melanin. A possible explanation, involving a proposed vestigial tapetum, is given in order to explain the correlation of melanosome counts and sensitivity to light damage.

• Research Organization: Institute of Molecular Biophysics, Florida State University, Tallahassee
• OSTI ID: 5513200
• Journal Information: Invest. Ophthalmol. Visual Sci.; (United States), Journal Name: Invest. Ophthalmol. Visual Sci.; (United States) Vol. 22:2; ISSN IOVSD
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BODY
BODY AREAS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EYES
FACE
HEAD
HYDROXY COMPOUNDS
MAMMALS
MELANIN
MICROSCOPY
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHOTOSENSITIVITY
PIGMENTS
RADIATIONS
RATS
RETINA
RODENTS
SENSE ORGANS
SENSITIVITY
TISSUE DISTRIBUTION
VERTEBRATES
VISIBLE RADIATION