| PCB Exposure and In Vivo CYP1A2 Activity among Native Americans Edward F. Fitzgerald,1 Syni-An Hwang,2 George Lambert,3 Marta Gomez,2 and Alice Tarbell4 1University at Albany, School of Public Health, Rensselaer, New York, USA; 2New York State Department of Health, Center for Environmental Health, Troy, New York, USA; 3University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical
School, New Brunswick, New Jersey, USA; 4Akwesasne Task Force on the Environment, Mohawk Nation at Akwesasne, Hogansburg, New York, USA Abstract
Cytochrome P-450 1A2 (CYP1A2) is an enzyme involved in the metabolic activation of some carcinogens and is believed to be induced by xenobiotics. Very few studies, however, have investigated the association between environmental exposures and in vivo CYP1A2 activity in humans. To address this issue, a study was conducted of CYP1A2 activity among Native Americans exposed to polychlorinated biphenyls (PCBs) from the consumption of fish from the St. Lawrence River. At the Mohawk Nation at Akwesasne (in New York and in Ontario and Quebec, Canada) , 103 adults were interviewed, and they donated blood for serum PCB analysis and underwent the caffeine breath test (CBT) , a safe and noninvasive procedure that uses caffeine as a probe for CYP1A2 activity in vivo. The results supported the findings of other studies that CBT values are higher among smokers and men and lower among women who use oral contraceptives. Despite a relatively low average total PCB body burden in this population, the sum of serum levels for nine mono- or di-ortho-substituted PCB congeners showed positive associations with CBT values (p = 0.052 wet weight and p = 0.029 lipid adjusted) , as did toxic equivalent quantities (TEQs ; p = 0.091 for wet weight and 0.048 for lipid adjusted) . Regarding individual congeners, serum levels of PCB-153, PCB-170, and PCB-180 were significantly correlated with CBT values. The results support the notion that CYP1A2 activity may be a marker of an early biological effect of exposure to PCBs in humans and that the CBT may be a useful tool to monitor such effects. Key words: cytochrome P-450 1A2, hazardous waste, Indians, North American, PCB, polychlorinated biphenyls. Environ Health Perspect 113: 272-277 (2005) . doi:10.1289/ehp.7370 available via http://dx.doi.org/ [Online 9 December 2004]
Address correspondence to E.F. Fitzgerald, University at Albany, School of Public Health, One University Place, Rensselaer, NY 12144 USA. Telephone: (518) 402-1062. Fax: (518) 402-0380. E-mail: eff02@health.state.ny.us We thank the study participants, the Akwesasne Task Force on the Environment, and the following persons for their past and present help: A. Casey, M. Cayo, A. Jacobs, K. Jock, B. LaFrance, K. Langguth, T. Lauzon, F.H. Lickers, and P. Worswick. This work was supported in part by the National Institute of Environmental Health Sciences (grants 11256 and 2P42-ES04913) , Agency for Toxic Substances and Disease Registry (grant H75/ATH298312) , and the U.S. Environmental Protection Agency (grant R829391) . The authors declare they have no competing financial interests. Received 30 June 2004 ; accepted 9 December 2004. The full version of this article is available for free in HTML or PDF formats. |
