Numbers of cortical vitreous cells and onset of cataracts in Royal College of surgeons rats.
Royal College of Surgeons (RCS) rats have hereditary retinal degeneration with associated posterior subcapsular opacities. A link between light, retinal degeneration, and cataracts may consist in peroxidation of polyunsaturated fatty acids of rod outer segment lipids to yield water-soluble toxic aldehydes that can traverse the vitreous and react with bow cells and posterior lens fibers. In an immune reaction to the retinal degeneration, macrophages multiply in the retina and in the cortex of the vitreous. In dystrophics, the cortical vitreous separates readily from attachments to retina, ciliary body and lens, and from the vitreous gel. This web-like structure was stained and spread on a counting chamber. Cells were counted at 15-130 postnatal days in pink- and black-eyed RCS dystrophics and in congenic controls to correlate numbers of cells, temporal and geographic patterns of retinal degeneration, and onset of opacities. Rats were reared in cyclic light (10-40 lux inside the cage) and fed a natural ingredient diet (NIH-07). Cortical vitreous cells increased markedly in pink- and black-eyed dystrophics at 50-53 days when slit-lamp detectable opacities occurred in both. The increase was 4.6-fold in pink- and 2.3-fold in black-eyed rats compared with controls. At 50-53 days, the dystrophy affected all quadrants of the retina severely in pink-eyed RCS but only the inferior periphery in black-eyed RCS. Consequently, severe degeneration in one quadrant may suffice to initiate an opacity.(ABSTRACT TRUNCATED AT 250 WORDS)
Hess
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Office of the Scientific Director, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892.
O'Keefe
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Kuwabara
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Westney
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D000375:Aging; D000818:Animals; D002386:Cataract / Q000209:etiology*; D002452:Cell Count; D002940:Circadian Rhythm; D005127:Eye Color; D008027:Light; D008264:Macrophages; D051381:Rats; D011922:Rats, Mutant Strains; D012162:Retinal Degeneration / Q000150:complications / Q000473:pathology*; D014822:Vitreous Body / Q000473:pathology*