Cataracts Due to Deficiencies of Phenylalanine and of Histidine in the Rat. A Comparison with Other Types of Cataracts

Abstract

The lenticular changes observed in rats deficient in phenylalanine, histidine, tryptophane or riboflavin were: general haziness, separation of the superficial fibers, widening of the sutures, diffuse and granular opacities in the cortex, granular degeneration of the superficial cortex, the appearance of a refractile line separating cortex and nucleus, and dense nuclear opacity of variable extent. The characteristic changes in each deficiency are described and illustrated. Lenticular changes of some degree were observed in deficiency of protein and of each of the indispensable amino acids except arginine. When rats deficient in phenylalanine or histidine were returned to the control diet, a reversal of superficial changes resulted, though the dense nuclear opacities were found to be irreversible. The spontaneous cataracts observed in 2 litters of rats, and cataracts in a rat on a high tyrosine diet are also described.