Abstract
Abstract: :
Purpose: To investigate the changes of retina due to vitamin E deficiency and to determine the effects of vitamin A supplementation. Methods: Male infant rats from normal mothers were weaned at 20 days of age and divided into two groups: Group 1, E(–), rats were fed a vitamin E–deficient diet; Group 2, E(–)A(+), rats were fed a vitamin E–deficient diet and injected intraperitoneally with 5000IU of vitamin E per 2 week. At 16 months of age, the retinal changes of these rats were examined by transmission electron microscopy (TEM). Results: The body weight between the two groups showed no significant difference (P=0.0686, t–test comparison of means). The serum vitamin E level in both E(–) and E(–)A(+) were less than 0.1mg/dl. The serum vitamin A level was significantly higher in the E(–)A(+) rats than that in the E(–) rats (P=0.0320, t–test comparison of means). TEM showed more fine granules in the retinal pigment epithelium in the E(–) rats than those in the E(–)A(+) rats. The pigment epithelium was comprised of eight or more layers in the E(–)A(+) rats, but five or less in the E(–) rats. There were some abnormal structures in the retina in the E(–) rats. The number of photoreceptor nuclei was decreased and the outer nuclear layer was thin in the E(–) rats. 0n the other hand, there were many granules in the pigment epithelium of retina, and many photoreceptors outer segments in the E(–)A(+) rats. The outer nuclear layer was more thick in the E(–)A(+) rats than in E(–) rats. Conclusions:The present study suggests that the retina is obviously damaged by vitamin E–deficiency and that vitamin A has a protective effect against the retinal damages caused by vitamin E–deficiency.
Keywords: retinal pigment epithelium • oxidation/oxidative or free radical damage • microscopy: electron microscopy