ISSN:
1432-0738
Schlagwort(e):
Styrene inhalation
;
Phenobarbital
;
Methylcholanthrene
;
Acetone
;
Microsomal drug-metabolizing enzymes
;
Glutathione
;
Thioethers
;
Lung
;
Liver
;
Rat
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Abstract Pulmonary changes in glutathione (GSH) indicated by the concentration of non-protein sulphydryls showed a decrease of 43% in rats exposed for 5 h per day three times to 500 cm3/m3 (2100 mg/m3) styrene vapour. In these rats, only a marginal decrease was observed in the pulmonary cytochrome P450 oxidative metabolism. Following a single 24-h inhalation exposure to 500 cm3/m3 styrene, the decreases in GSH were 66% in lung but only 16% in liver. On the other hand, a multifold increase in the disposition of thioether compounds was found in urine. Pulmonary cytochrome P450-dependent metabolism was decreased, shown by low residual activities of 7-ethoxyresorufin (〈20%), 7-ethoxycoumarin (53%) and 7-pentoxyresorufin O-dealkylases (76%). Epoxide hydrolase and GSH S-transferase enzyme activities which catalyze styrene detoxification were not decreased. Styrene exposure (24 h) of acetone-, phénobarbitalor 3-methylcholanthrene-pretreated rats resulted in pulmonary effects different from each other and from those of styrene alone. Acetone potentiated the lung effect and elevated 1.5-fold urine thioether output. Inducer pretreatment seemed to be a factor aggravating styrene toxicity; in effect this was clearest in acetone-induced rats. In general, GSH depletion accompanied by inhibition of cytochrome P450-dependent oxidative drug metabolism were the earliest biochemical lesions manifested in styrene-exposed lung.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01973457
