Sister-chromatid exchanges in human bronchial epithelial cells.

Abstract One method of assessing the genotoxic effects of exposure to environmental agents is by determining the frequency of sister chromatid exchanges in exposed cells. In the present study, a procedure for observing sister chromatid exchanges in adult human bronchial epithelial cells exposed to a carcinogen has been developed. Using this procedure, the frequencies of sister chromatid exchanges in untreated cells from two individuals were found to be 5.1 ± 1.8 and 6.5 ± 1.4 per metaphase (mean ± SD). Cells from the first individual exposed to 7,12-dimethylbenz[ a ]anthracene at 0.5, 1 and 2 μg/ml had 7.8 ± 2.2, 13 ± 3.1, 18.7 ± 3.7 sister chromatid exchanges per metaphase, respectively. This method is likely to be particularly useful for observing sister chromatid exchanges in cells that have a relatively slow growth rate in the presence of bromodeoxyuridine and for which preparation of a large number of metaphase chromosomes is difficult. In addition, the procedure provides a means of assessing genotoxic effects in the lung by examining the direct effects of pollutants on the chromosomes of the target cells for human lung cancer.