DEVELOPMENT OF AN IN-VITRO SYSTEM FOR STUDYING EFFECTS OF NATIVE AND PHOTOCHEMICALLY TRANSFORMED GASEOUS COMPOUNDS USING AN AIR LIQUID CULTURE TECHNIQUE/

An experimental in vitro model was established to study the effects of environmentally relevant gaseous compounds on lung cells. The technic al unit consists of a gas reaction chamber (2400.1) with a sun-simulat or to produce and photochemically transform gaseous mixtures and compo unds at the upper limit of environmentally relevant concentrations. Ra t lung cells were exposed on transwells in a perspex chamber inside an incubator, into which the gaseous mixtures were conducted. Analysis o f the gas phase was performed inside the reaction chamber and at the o utlet of the exposure box to assess the effective exposure concentrati ons. The growth of the cells on PET-membranes allowed direct cell expo sure with a minimal barrier for contact between gas and cells. To asse ss the cytotoxicity, the following biochemical markers for the cellula r status after exposure were determined: amount of dsDNA, WST, BrdU-in corporation after exposure, LDH release into the culture medium, activ ity of glutathione S-transferases and esterases. Using this system, do se-dependent cytotoxicity was found for NO2 in the concentration range from 80 to 360 ppb and strong cytotoxic effects for ozone in the conc entration range from 225 to 500 ppb. Exposure to purified air did not show significant effects. In addition, some irradiated gas mixtures (p hoto smog) showed cytotoxicity whereas non-irradiated mixtures did not . (C) 1998 Elsevier Science Ireland Ctd. All rights reserved.