[Analysis of the biological effect of city smog extract. III. Comparative investigations on the effect of city smog extracts on cell replication and DNA-synthesis of kidney cells in vitro from the primate Cercopithecus aethiops (author's transl)].

We analysed the cytotoxic effect of city smog extracts from a heavy industrialized area using kidney cell cultures from the primate Cercopithecus aethiops.--Using logarithmically growing cell cultures we determined cell replication and the rate of DNA-synthesis after incorporation of 3H-thymidine.--In presence of city smog extracts we found a dose dependent reduction of cell replication and of DNA-synthesis. In presence of high concentrations (BP-aquivalent 0.25-0.5 microgram/ml) of city smog extract we found no increase in cell number over a period of 72 h. Under the same conditions hardly any DNA-synthesis was detected.--In presence of middle and low concentrations of city smog extract a dose- and time-dependent increase in cell number and rate of DNA-synthesis was detected.