Abstract
Mercapto compounds were tested as to their chemical reactivity with nitrogen mustard (HN2) and its N-oxide (HN2-O) in vitro, and as to their preventive action in vivo against rat leucopenia induced by the same agents. Of these compounds, L-cysteine alone was found to show remarkable activity in vivo, while D-cysteine and L-cysteine methyl ester were proved to be only slightly effective. Administration of L-cysteine 30 min. after HN2-O injection prevented to some extent the leucopenia of Yoshida sarcoma rats without being deprived of its anti-tumor effect.
