title: Platelet monoamine oxidase B activity in workers exposed to styrene.
abstract: A cross-sectional study was conducted to evaluate monoamine oxidase type B (MAO-B) activity in platelets as a biomarker of effect of styrene and perchloroethylene exposures. MAO-B is an enzyme system involved in dopamine catabolism, the impairment of which has been postulated as a mechanism of styrene-induced neurotoxicity. We previously observed an inverse association between blood styrene and MAO-B among reinforced plastics manufacturing workers. The present study included 59 male boat plant workers exposed to styrene (exposure range < 1-144 ppm, 8-h TWA). Two comparison groups comprised six male dry cleaning workers exposed to perchloroethylene (PCE; exposure range < 2-37 ppm) and 14 male laundry workers not exposed to either agent. Respiratory protection was not used by any of the styrene- or PCE-exposed workers; thus, air concentrations were regarded as valid exposure indicators. MAO-B activity (pmol/10(8) cells/h) was measured in peripheral blood platelets, using phenylethylamine as substrate. Only small overall mean differences in MAO-B were observed among the three groups; mean values were 4.21, 4.51, and 4.12 for the styrene-exposed, PCE-exposed, and laundry workers, respectively. Despite the absence of gross differences among the groups, styrene exposure was inversely related to MAO-B. Mean values for four increasing exposure group quartiles were: 5.60, 4.13, 3.69, and 3.44. The Spearman rank correlation coefficient for styrene with MAO-B was -0.41. Adjustment for age, medication use, smoking, and alcohol consumption had only a minimal effect on this trend.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Environmental Health, University of Washington, Seattle 98195.
authors.forename: H
authors.initials: H
authors.lastname: Checkoway
authors.forename: D
authors.initials: D
authors.lastname: Echeverria
authors.forename: J D
authors.initials: JD
authors.lastname: Moon
authors.forename: N
authors.initials: N
authors.lastname: Heyer
authors.forename: L G
authors.initials: LG
authors.lastname: Costa
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D001792:Blood Platelets / Q000201:enzymology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000097:blood*; D016273:Occupational Exposure; D020058:Styrene; D013343:Styrenes
chemical_list: D015415:Biomarkers; D013343:Styrenes; D020058:Styrene; D008995:Monoamine Oxidase