Vitamin E deficiency and the retina: photoreceptor and pigment epithelial changes.
To investigate the role of normal vitamin E levels and the interrelationships between vitamin E and A in maintaining the visual cells of the retina, weanling female Sprague-Dawley rats were fed vitamin E-free diets differing tenfold in their vitamin A content (0.8 and 8.0 mg of retinol per kilogram of diet). Rats on vitamin E-free diets with the higher vitamin A level exhibited marked disruption of photoreceptor outer segment membranes and a fivefold increase in the number of lipofuscin granules in the pigment epithelial cells which ingest these membranes. Rats on vitamin E-free diets with the lower vitamin A level showed the same retinal damages plus significant loss of photoreceptor cells compared to age-matched rats on control diets. Rods and cones were involved equally, and their pattern of loss was not like that found in vitamin A deficiency. Normal levels of vitamin E probably protect photoreceptor membranes from oxidative damage and retard the accumulation of their remnants and other products of lipid breakdown in the pigment epithelium. The vitamin A status of rats has a significant influence on the extent of damage induced by vitamin E deficiency.
D000818:Animals; D004032:Diet; D005260:Female; D008062:Lipofuscin; D008247:Lysosomes / Q000473:pathology; D010786:Photoreceptor Cells / Q000473:pathology* / Q000648:ultrastructure; D010857:Pigment Epithelium of Eye / Q000473:pathology* / Q000648:ultrastructure; D051381:Rats; D012164:Retinal Diseases / Q000209:etiology* / Q000473:pathology; D014801:Vitamin A / Q000502:physiology; D014810:Vitamin E / Q000502:physiology; D014811:Vitamin E Deficiency / Q000150:complications* / Q000473:pathology
D008062:Lipofuscin; D014801:Vitamin A; D014810:Vitamin E