TOXIC ACTION OF ETHYLENE-OXIDE ON PULMONARY CELLS (L132) CULTURED UNDER AEROBIC CONDITIONS

In environmental health, inhalation is the most prominent route of eth ylene oxide (EO) exposure. In the current study, human embryonic pulmo nary epithelial cells (L132 cell line) were exposed to EO following a prior adaptation to atmospheric conditions. A comparative study betwee n two EO exposure conditions (0.07 and 0.18 g/m(3) gas injections) was carried out after a 1-h incubation. Whereas control cells were expose d to a pure air stream. The EO cytotoxicity was established by electro n microscopy and LDH and ATP determinations after 1, 3, 6 and 24 h fol lowing the exposure. The ultrastructural examination revealed a remark able vacuolisation of the exposed cells leading to cell death. In spit e of this modification, the number of mitochondria and the content of endoplasmic reticulum increased in the L132 cells. For both exposure c oncentrations LDH was released into the extracellular milieu. In the p resence of the high EO concentration, LDH activity increased with resp ect to the post-exposure time involving alteration of the membrane and permeability. For low EO exposure, ATP synthesis was significantly in creased after 1 h of post-exposure (P < 0.01) and decreased to normal levels after 6 h. For the high EO concentration, however, ATP continua lly increased with respect to the post-exposure lime. This indicates c ellular stimulation and suggests the activation of a defense mechanism . This study shows a direct EO cytotoxicity on L132 cells cultured in atmospheric conditions.