Organohalogens and their hydroxylated metabolites in the blood of pigs from an open waste dumping site in south India: association with hepatic cytochrome P450.
The concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and their hydroxylated metabolites (OH-PCBs and OH-PBDEs) were measured in the blood of Eurasian wild pigs (Sus scrofa) from a municipal waste open dumping site (DS) and a reference site (RS) in South India. We showed that contamination with OH-PCBs was higher in female pigs from the DS than in all other adult pigs. The highest OH-PCB concentrations were found in piglets from the DS. Moreover, the hepatic expression levels of CYP1A and CYP2B were higher in piglets than in their dam, implying metabolism of PCBs by cytochrome P450 (CYP) enzymes. The OH-PCB congener profiles differed according to sex and collection sites, possibly because of variations in the expression levels of phase I and phase II enzymes among individual pigs, differences in the exposure sources, and maternal transfer of parent PCBs. The hepatic CYP1A expression levels were positively correlated with the blood concentrations of 4OH-CB107, 4OH-CB162, and 4OH-CB187, implying CYP1A-dependent formation of these OH-PCBs in the pig liver. We found no significant correlations between the blood concentrations of OH-PCBs and thyroid hormones (THs); however, the thyroxin (T4) levels were lower in pigs from the DS than in pigs from the RS. Our limited dataset suggest that induced CYP enzymes accelerate the metabolism of xenobiotics and endogenous molecules in pigs. Thus, besides parental compounds, the risk of hydroxylated metabolites entering wildlife and humans living in and around municipal open waste dumping sites should be considered.
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan. Electronic address: hazuki.mizukawa@vetmed.hokudai.ac.jp.
Hazuki
H
Mizukawa
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Kei
K
Nomiyama
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Tatsuya
T
Kunisue
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Michio X
MX
Watanabe
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Annamalai
A
Subramanian
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Hisato
H
Iwata
Laboratory of Toxicology, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan.
Mayumi
M
Ishizuka
Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.
Shinsuke
S
Tanabe
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D055768:Halogenated Diphenyl Ethers / Q000097:blood*; D006900:Hydroxylation; D007136:Immunoglobulins / Q000097:blood; D007194:India; D008099:Liver / Q000378:metabolism; D008297:Male; D011078:Polychlorinated Biphenyls / Q000097:blood*; D012727:Sex Characteristics; D034421:Sus scrofa / Q000378:metabolism*; D013963:Thyroid Hormones / Q000097:blood; D014801:Vitamin A / Q000097:blood; D064091:Waste Disposal Facilities
D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D007136:Immunoglobulins; D013963:Thyroid Hormones; D014801:Vitamin A; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls
Dumping site; Hydroxylated metabolite; Pig; Polychlorinated biphenyl (PCB); Thyroid hormone