Availability of Dibenzoylcystine for Growth of the Young White Rat

Young white rats were fed l-cystine and dibenzoyl-l-cystine as supplements to a basal diet known to be low in its content of cystine, in an attempt to determine whether dibenzoyl-l-cystine could be hydrolyzed in the organism and thus serve as a significant source of cystine for purposes of growth. To detoxicate any benzoic acid which might be formed in the hydrolysis and afford optimal conditions for observation of the growth-promoting effect of any cystine formed, glycine was also added to the diets. NO evidence was obtained that dibenzoyl-l-cystine under the experimental conditions employed could serve as an effective source of cystine for purposes of growth.