CYSTINE DEFICIENCY IN THE ALBINO RAT

In three separate batches of young Wistar strain albino rats from two different sources, kept on the Sherman‐Merrill cystine‐deficient diet, a large proportion developed a characteristic syndrome and died when untreated. Cystine or methionine prevented this; once the symptoms had definitely appeared cystine brought about recovery in most cases, but methionine was without effect. Males were markedly more susceptible than females. It is suggested that the long deprivation of cystine and methionine shows a difference in the readiness with which these amino acids can be utilised.