[Potential role of the antimutagenic effect of xymedone in modification of immunoreactivity].

Effects of the pyrimidine derivatives of xymedone and methyluracil upon the induction of point mutations of the base pair substitution type in the Salmonella/microsome test and the frequency of chromosome aberrations in the lymphocytes of patients with the chronic osteomyelitis diagnosis. Xymedone more effectively than methyluracil inhibited the induction of point mutations by nitrosomethylurea. In the case of the cyclophosphane induced mutagenesis, the two preparations exhibited comparable antimutagen effects. Both xymedone and methyluracil (1.5 g/day, 10 days) reduced the (increased) frequency of chromosomal aberrations in the lymphocytes of patients with the chronic osteomyelitis diagnosis. The anticlastogenic effect of methyluracil vanished 5 days after termination of the 10-day administration course, while xymedone exhibited an afteraction anticlastogenic effect over this period. Interrelation of the antimutagen effect and immunomodulating activity of xymedone is discussed.