Excretion of N-acetyl-S- (1-phenyl-2-hydroxyethyl) - cysteine and N-acetyl-S- (2-phenyl-2-hydroxyethyl) - cysteine in workers exposed to styrene.
International Symposium on Biological Monitoring in Occupational and Environmental Health. Espoo (FIN), 1996/09/11.
Copyright (c) 1997 Elsevier Science B.V. All rights reserved.
Styrene (S) has been shown to be responsible for neurotoxic effects, including behavioural changes and neuroendocrine disturbances.
The initial step of S metabolism is conversion to styrene 7,8-epoxide (SO), which is present in two enantiomeric forms [ (R) (+) - SO and (S) (-) - SO] ; this electrophilic intermed iate is considered to be directly responsible for most toxic effects of S. The major urinary metabolites derived from the biotransformation of SO in man are mandelic acid (MA) and phenylglyoxylic acid (PGA).
In rats an alternative pathway has been demonstrated, which involves the conjugation of SO to glutathione (GSH), leading to the excretion of two specific mercapturic acids, N-acetyl-S- (1-phenyl-2-hydroxyethyl) - cysteine [M1] and N-acetyl-S- (2-phenyl - 2-hydroxy-ethyl) - cysteine [M2] ; a close relationship has been found between exposure to S and urinary excretion of M1 and M2 in rats.
As a consequence of the chiral nature of SO, both M1 and M2 consist of two diastereoisomers (M1-R'M1-S'M2-R'and M2-S'). Early reports have shown that the conversion of S to mercapturic acids is much lower in man (below 1% of the absorbed dose) than in rats (about 10%). (...)
Mots-clés Pascal : Styrène, Solvant organique, Exposition professionnelle, Médecine travail, Homme, Toxicocinétique, Pharmacocinétique, Métabolisme, Urine, Liquide biologique, Surveillance biologique, Glutathion, Mercapturique acide, Cystéine(N-acétyl)
Mots-clés Pascal anglais : Styrene, Organic solvent, Occupational exposure, Occupational medicine, Human, Toxicokinetics, Pharmacokinetics, Metabolism, Urine, Biological fluid, Biological monitoring, Glutathione
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Cote : 97-0528842
Code Inist : 002B03L04. Création : 13/02/1998.