The analysis of the variation in the mutation rate in the fractionated progeny of treated males, revealed a marked differential cell stage response to the various chemical series investigated. The mustard derivatives of amino-acids (particularly L-phenylalanine) exert their minimal mutagenicity on mature sperm, but possess an appreciable activity on other stages of spermatogenesis, including spermatogonia. The carboxylic-acid mustards produce their maximal effect on an early spermatid, but are practically ineffective on spermatocytes and spermatogonia. The amine mustard corresponding to the phenylalanine derivative is effective on the stages of spermiogenesis (including the early spermatids) as well as on the spermatocytes, but is inactive on the spermatogonia (at least the primary stages). The response of the gonia, therefore, is a function of the amino-acid moeity of the mutagen, and is not merely due to the presence of an amino-group in the molecule.
Studies on Carcinostatic Substances. XXXIII. Preparation of Derivatives of Nitrogen Mustard of Strongly Basic Character.
