DEFICIENCIES OF VITAMIN-E AND VITAMIN-A IN THE RAT - RETINAL DAMAGE AND LIPOFUSCIN ACCUMULATION

  • 1 January 1980
    • journal article
    • research article
    • Vol. 19  (9) , 1030-1037
Abstract
The interrelationships of vitamins E and A in maintaining various structural components of the retina were studied in 4 groups of weanling female rats fed purified diets adequate or deficient in each vitamin: +E, +A; -E, +A; +E, -A; and -E, -A. Groups deficient in retinol (-A) were supplemented with retinoic acid. After 14, 21 and 35 wk, the retinas were examined histologically and ultrastructurally. At 35 wk, the doubly deficient rats (-E, -A) had lost 92% of their rod nuclei; rats deficient in vitamins A (+E, -A) or E (-E, +A) alone lost 34% and 20%, respectively. Vitamin E deficiency resulted in extensive lipofuscin deposits in the retinal pigment epithelium as early as 21 wk, but the presence of vitamin A doubled the number of lipofuscin granules (-E, +A vs. -E, -A) and induced a greater increase in their autofluorescence. Another clear influence of vitamin A was seen when +E, +A retinas autofluoresced more than +E, -A retinas, which had similar numbers of granules, and more than -E, -A retinas, which had about twice as many lipofuscin granules. In the retina, unlike the uterus, the lipofuscin-specific autofluorescence and lipofuscin granule number were not proportional. The numbers of granules were influenced by vitamins E and A; the intensity of lipofuscin-specific autofluorescence was determined almost exclusively by vitamin A. Probably the accelerated loss of photoreceptor cells in -E, -A retinas resulted from oxidation of membranes and oxidation of retinal vitamin A stores in the absence of vitamin E protection.