Search

We analyzed the cytotoxic effect of a city smog extract from a large urban area, employing mouse macrophages in vitro. In parallel experiments we tested carcinogenic and non carcinogenic polycyclic aromatic hydrocarbons: benzo(a)pyrene, 7, 12-dimethylbenzanthracene, pyrene and anthracene. City smog extract induced a dose-dependent reduction of cell viability and an alteration in cell membrane permeability. In contrast to city smog extract the carcinogenic and non carcinogenic polycyclic aromatic hydrocarbons produced no detectable cytotoxic effects in the dose range we analyzed. Possible implications of the cytotoxic effect of city smog extract on the lung are discussed.

We analysed the toxic effect of lead chloride employing peritoneal macrophages of the mouse. Toxic effects were determined using the following parameters: viability by dye exclusion test, membrane permeability estimating release of lactate dehydrogenase and carbohydrate metabolism measuring lactate production. Our results demonstrate that Zinc iones in a concentration of 1 X 10(-5) M reduce the toxic effect of lead chloride of 2-4 X 10(-4) M.

Airborne dust is toxic for cells cultured in vitro and able to transform these cells to cancerous. The effect of extracts from atmospheric dust has been investigated. The dust samples were extracted by means of DMSO alone or in combination acetone-DMSO. Dosage of the extract was done according to its benzo(a)pyrene content (mug/ml medium). Dust extract with a concentration of 1 mug benzo(a)pyrene/ml exerted a toxic effect upon mouse macrophages (cell line IC-21) and human lymphocytes after stimulation. The degree of toxicity was estimated from the percentage of damaged cells seen in the dye exclusion test and from the amount of lactate dehydrogenase and lactate released into the medium in the case of macrophages. In the case of lymphocytes the degree of toxicity was estimated from the extent of inhibition of DNA synthesis. In the carcinogenicity test, hamster kidney cells were first treated with the extract and then incubated with Simian Virus (SV-)40. Treatment of the cell cultures with extract from airborne dust in a concentration of 0.01 and 0.1 mug benzo(a)pyrene/ml clearly enhances the rate of transformation caused by SV 40.

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.

A city smog extract from an urban area inhibits the cell growth of hamster kidney cells in vitro. Parallel to an inhibition of cell multiplication a diminished rate of total DNA synthesis appeared. The number of cells in DNA synthesis is depressed in presence of city smog extract. These phenomena revealed a dose-response relationship. The biological effect of city smog extract is discussed.

The cell growth of exponentially growing kidney cell cultures of Cercopithecus aethiops was determined by estimation of protein content. The effect of city smog extracts and its polyaromatic fractions on cell growth was examined. Based on the benzo(a)pyren-content the crude extract of city smog exerted the strongest inhibition of cell growth, followed by non purified and purified fraction of polyaromates. The inhibition of cell growth was dose dependent. Results indicate, that for cell growth inhibition are of importance concentrations of toxic substances and exposition time.