title: Measurement of human CYP1A2 induction by inhalation exposure to benzo(a)pyrene based on in vivo isotope breath method.
abstract: Cytochrome P450 1A2 (CYP1A2) is an enzyme involved in the metabolic activation of certain carcinogens, and inducible by toxic substrates. To date, few studies have investigated in vivo CYP1A2 induction in humans and its relationship to polycylic aromatic hydrocarbons (PAHs) like benzo(a)pyrene (BaP). Non-smoking healthy male coke-oven workers (n = 30) were recruited as 'exposure' group, and non-smoking healthy office workers in the same city (n = 10) were selected as 'control' group, to test whether high inhalation exposure to PAHs can induce CYP1A2 activity in human livers. Significantly higher inhalation exposure of PAHs were found among the exposure group compared to the control. Inhalation BaP exposure concentration in the exposure group was more than 30 times higher than the control group (p < 0.001). However, the exposure group did not exhale significant higher levels of (13)CO2/(12)CO2 in breath samples (p = 0.81), and no significant relationship was found between the inhaled BaP concentration and the (13)CO2/(12)CO2 ratio (p = 0.91). A significant association was found between the (13)CO2/(12)CO2 exhalation and dietary BaP intake level. Hepatic CYP1A2 activity/induction level was not effected by inhaled BaP but was altered by ingestion of BaP.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: duan_jasmine@126.com.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Duan
authors.affiliation: Jiangsu Key Laboratory of Environmental Engineering, Jiangsu Provincial Research Academy of Environmental Sciences, Nanjing 210036, China.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Shen
authors.affiliation: Anshan Environmental Monitoring Center, Liaoning 114004, China.
authors.forename: Hongbiao
authors.initials: H
authors.lastname: Yang
authors.affiliation: University of Medicine and Dentistry of New Jersey/Rutgers University, Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA.
authors.forename: George
authors.initials: G
authors.lastname: Lambert
authors.affiliation: China National Environmental Monitoring Center, Beijing 100012, China.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Wei
authors.affiliation: Nicholas School of the Environment and Global Health Institute, Duke University, NC 27708, USA; Duke Kunshan University, Kunshan City, Jiangsu Province, China. Electronic address: junfeng.zhang@duke.edu.
authors.forename: Junfeng Jim
authors.initials: JJ
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity*; D001564:Benzo(a)pyrene / Q000378:metabolism / Q000633:toxicity*; D001944:Breath Tests; D002273:Carcinogens / Q000633:toxicity; D003077:Coke; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism*; D004784:Environmental Monitoring; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D007554:Isotopes; D008099:Liver / Q000378:metabolism; D008297:Male; D016273:Occupational Exposure / Q000032:analysis
chemical_list: D000393:Air Pollutants; D002273:Carcinogens; D003077:Coke; D007554:Isotopes; D001564:Benzo(a)pyrene; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2
keywords: Benzo(a)pyrene (BaP); Caffeine Breath Test (CBT); Cytochrome P450 1A2; Exposure biomarker