Differential response to induction of chromosomal aberrations between female and male mice treated with a low dose of cyclophosphamide

We have assessed the mitotic index and induction of chromosomal aberrations produced by the administration of a single low dose of cyclophosphamide (C P) to male, non-pregnant female and pregnant female of CD-1 strain mice. Th e aim of the study was to evaluate the differences in response between sexe s of the same species (mice) and between individuals of the same sex (femal es) treated with this compound. CP administration increased the frequency o f chromosomal aberrations significantly in both sexes. However, there was a clear difference in sensitivity between the sexes, since the effects of CP were more pronounced in males than in females, while pregnant mice showed fewer chromosomal aberrations than those not pregnant. The differences foun d in this study were probably due to differences in the enzyme system respo nsible for the metabolism of CP and its interaction with the hormonal envir onment of each sex. Med Sci Res 27:193-196 (C) 1999 Lippincott Williams & W ilkins.