[The effect of organochlorine compounds on the induction of sister chromatid exchanges in cultured human lymphocytes].

In this study, first, we investigated the effect of 7,8-benzoflavone (ANF), mitomycin C (MMC), a well-known genotoxic compound, and ANF plus MMC on the induction of sister chromatid exchanges (SCEs) in human whole-blood cultures. Second, we examined the effect of mixture of organochlorine compounds, which very resembled their contamination of healthy people in its composition, on the induction of SCEs in the same blood culture system in order to clarify their genotoxicity as a whole. The following results were obtained. 1. ANF and MMC significantly enhanced the number of SCEs/cell at the concentrations of 4 x 10(-5) M and 10(-8)M, respectively. When both of the compounds were simultaneously added in the blood cultures, their effects on the induction of SCEs seemed to be additive. 2. Without ANF in the blood culture system, namely, an usual system of the SCEs experiment, we could not find a dose-response relationship between the concentration of the mixture of organochlorine compounds and the induction of SCEs/cell. With ANF, however, we observed a fairly good dose-response relationship between them. 3. In the whole-blood culture system with ANF, we found significantly great number of SCEs/cell at the level of twenty times higher concentration of the organochlorine compounds than the ordinary level. According to the results described above and of our other studies, 50% effective concentration (EC50, about 2 SCEs/cell higher than control SCEs/cell) of the mixture was considered to be about 5 times greater level over the general one.(ABSTRACT TRUNCATED AT 250 WORDS)