Further studies on the chemistry of photoreceptor membranes of rats fed an essential fatty acid deficient diet

Our prior studies have shown that vertebrate rod photoreceptor membranes contain large amounts of polyunsaturated fatty acids, the precursors of which must be obtained from the diet. Dietary manipulation to lower the polyunsaturated fatty acid levels in these membranes produced only minor changes in the fatty acids and no changes in phospholipid class composition. In the present paper, we report further studies on the photoreceptor membranes of rats raised on fat-free (experimental) or lab chow (control) diets. Our data show that the amount of rhodopsin per eye, the ratio of phospholipid to rhodopsin, and the proteins of the outer segment membranes are similar for both groups. Ultrastructural examination of the photoreceptor membranes from the control and experimental retinas show no detectable morphological differences.