IN-VIVO EXPOSURE TO OZONE PRODUCES AN INCREASE IN A 72-KDA HEAT-SHOCK-PROTEIN IN GUINEA-PIGS

Although several lines of evidence have suggested that oxidizing agent s can induce heat shock proteins (HSPs) in vitro, little is known abou t the induction of HSPs during in vivo exposure to oxidants. Guinea pi gs were exposed to ozone for 6 h and euthanized up to 72 h later. Prot eins from lavage cells and lung tissue were characterized by immunoblo tting with 72- and 73/72-kDa HSP monoclonal antibodies. Although 73-kD a HSP was expressed constituitively in lung tissue, it was not affecte d by ozone. In contrast, 72-kDa HSP was significantly increased in lav age cells and lung tissue of animals exposed to 0.4 and 0.66 parts/mil lion of ozone. Both heat treatment and arsenite induced 72-kDa HSP in cultured alveolar macrophages. The increase in 72-kDa HSP in the lavag e cell pellet peaked at 24 h after ozone, whereas the influx of polymo rphonuclear leukocytes peaked at 4 h. Examination of the induction of HSPs by ozone may provide clues to the development of ozone tolerance in humans and animals.