Deficiency Diets in Young Growing Rats. ∗

Summary

1. Young growing male rats fed 6 weeks a diet containing ample balanced protein and mineral supplement do not require exogenous choline. 2. Similar diets deficient in methionine alone or methionine and cystine cause pathologic changes in testes, kidney, liver and cardiovascular system. 3. Gross and histologic changes are demonstrated in methionine-deficient and methionine-cystine-deficient animals. 4. These changes are more marked in animals fed the diet deficient in methionine alone. Presence of cystine increases methionine requirement for growth and decreases methionine available for lipotropism. 5. An inverse thymus-testes weight relation is noted in animals fed a methionine-deficient diet.