title: Cyclophosphamide induced in vivo sister chromatid exchanges (SCE) in Mus musculus. I: Strain differences and empirical association with relative chromosome size.
abstract: The inducibility of sister chromatid exchanges (SCEs) by cyclophosphamide (CP) in bone marrow cells was evaluated in vivo in the three genetic strains of mice (C3H/s, C57BL/6J, and Balb/c). Female mice (10 to 12 wks old, mean = 22.9g, SD = 3.2g) were administered with nine hourly injections of 214.19 mg/kg 5-Bromo-2' deoxyuridine (BrdU) followed by 0, 0.048, 0.449, 4.585 or 46.93 mg/kg CP and 4 mg/kg colcemid. SCEs were evaluated following differential staining procedures of Perry and Wolff (1974). The base-line SCEs were similar in all strains with about ten SCEs/cell. Increasing CP concentrations yielded an increased level of SCEs. Most cells showed extensive damage in CP doses exceeding 4.55 mg/kg. No SCE evaluation was possible beyond this concentration. Strain differences were evident at every dose of CP, and Balb/c was the least susceptible strain to SCE induction. F1 hybrids involving C3H/s female and Balb/c male showed SCE values closer to Balb/c. Data on the association between chromosome length and frequency of SCEs are provided. They empirically establish a positive correlation (r = 0.90) between the two features. Most induced SCEs were interstitially located rather than terminally positioned on the chromosome.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects; D002875:Chromosomes / Q000187:drug effects* / Q000648:ultrastructure; D003434:Crossing Over, Genetic / Q000187:drug effects*; D003520:Cyclophosphamide / Q000494:pharmacology*; D005260:Female; D008297:Male; D008677:Metaphase; D051379:Mice; D008815:Mice, Inbred Strains; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D013045:Species Specificity
chemical_list: D003520:Cyclophosphamide