[Analysis of the biological effect of city smog extract. VI. Comparative investigations on the effect of city smog extracts and their fractions on DNA synthesis of hamster kidney and embryonic cells and kidney cells of the primate Cercopithecus aethiops (author's transl)].

We analyzed the effect of two samples of city smog extracts and their fractions from Duisburg on the rate of DNA synthesis of mammalian cell cultures. - We employed tissue cultures of kidney and embryonic cells from the Syrian golden hamster (Cricetus aureatus) and kidney cells from the African green monkey (Cercopithecus aethiops). The DNA synthesis was determined autoradiographically after incubation with 3H-thymidine. We found that both city smog extracts exerted a dose-dependent suppression of cellular DNA synthesis. Monkey kidney cells were more sensitive than rodent cells. Analysis of single fractions indicate that the inhibition of DNA synthesis is the result of combined effects of all fractions. At present time it is not possible to correlate the toxic effect of the complete extract special to a single fraction or compound group.