[Cytogenetic effect of cyclophosphamide in a culture of human lymphocytes following its activation in the bodies of mice].

Cytogenetic effect of cyclophosphamide in cultured human lymphocytes after its activation in C57BL/6 mice in vivo was investigated. Cyclophosphamide was injected intraperitoneally in mice for 30 min. at doses of 200, 400, 600, 800 and 1000 mg/kg. Blood serum with activated metabolites of cyclophosphamide was added to human lymphocyte culture. The dependence of the part of aberrant metaphases on the concentration of cyclophosphamide after the activation can be presented as equation rho==1-e-(KC+alpha)2 and the total number of breaks as X=e(KC+alpha)2-1, where rho is a part of aberrant metaphases, X is a number of breaks of chromosomes per cell, C is the concentration, K and alpha are coefficients. The part of chromatid breaks from the total number of chromosome damages is constant for all concentrations and the comprises on the average 79,11%. Only the chromatid type of exchanges are observed. Distribution of chromosome breaks in cells corresponds to geometrical, but not to Poisson's distribution. Cyclophosphamide belongs to the group of one-sited mutagens in its cytogenetic chatacteristics. The alkylating activity of cyclophosphamide metabolites, estimated by means of NBP test, increases up to the dose 400 mg/kg and then remains constant for the strain of mice studied, cytogenetic activity increasing. Cyclophosphamide does not produce cytogenetic activity without activation. To test chemical substances for mutagenic activity, it is suggested to activate them in the mouse organism with the following administrating blood serum of these animals with the metabolites of tested (or with primary) substances in the study of their mutagenic activity on human lymphocyte culture.