PMID- 20417310
OWN - NLM
STAT- MEDLINE
DCOM- 20100706
LR  - 20161125
IS  - 1532-0456 (Print)
IS  - 1532-0456 (Linking)
VI  - 152
IP  - 2
DP  - 2010 Aug
TI  - Effects of in ovo exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic 
      AHR/ARNT-CYP1A signaling pathways in common cormorants (Phalacrocorax carbo).
PG  - 224-31
LID - 10.1016/j.cbpc.2010.04.010 [doi]
AB  - Our previous studies have isolated multiple isoforms of aryl hydrocarbon 
      receptors (AHRs) and AHR nuclear translocators (ARNTs) in avian species. However, 
      roles of such genes on cytochrome P450 1A (CYP1A) expression are not fully 
      understood. To investigate the effects of dioxins on the hepatic expression 
      profiles of AHR1, AHR2, ARNT1 and ARNT2 in avian species, and whether the 
      expression levels of AHRs and ARNTs affect the transcriptions of CYP1A4 and 
      CYP1A5 genes, the eggs of common (great) cormorants (Phalacrocorax carbo) 
      collected from Lake Biwa, Japan, were in ovo administrated with 0, 1500 and 
      4500pg/g egg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and the hepatic 
      expression levels of AHRs, ARNTs and CYP1As in embryos were monitored with 
      two-step real-time RT-PCR. In young and adult cormorants collected from the same 
      location, the hepatic expressions of these genes were also measured to understand 
      the effects of growth stage. The residue levels of TCDD and other chlorinated 
      dioxin-like congeners (DLCs) in the body of cormorants were quantified with 
      high-resolution gas chromatography equipped with mass-spectrometry. There was no 
      observable effect of in ovo TCDD treatment even at the highest dosage on 
      mortality, body weight and morphology of the liver, heart, spleen, kidney and 
      lung in the embryos. The mRNA expression of ARNT2 was slightly suppressed by the 
      treatment with TCDD, while no alteration was observed for the expression of AHR1, 
      AHR2 and ARNT1. Expressions of CYP1A4 and CYP1A5 were dose-dependently enhanced 
      by TCDD, but CYP1A4 mRNA level increased more prominently than CYP1A5, indicating 
      the difference in induction efficiency between the CYP1A isozymes. Comparison of 
      hepatic mRNA levels of these genes among embryonic, young and adult cormorants 
      revealed that young and adult cormorants had greater CYP1A5 expression levels 
      than embryos, independently of the accumulation levels of DLCs. These results 
      suggest that the hepatic induction of each CYP1A by DLCs in cormorants occurs in 
      an isoform-specific manner and CYP1A5 expression, at least partially, depends on 
      the factors related to the growth of cormorants, but the transcriptional 
      processes of CYP1As are not related to the expression levels of AHRs and ARNTs. 
      This study yielded results supporting our previous observations that in reality, 
      high accumulation of DLCs induces hepatic CYP1A4 and 1A5 expressions in the wild 
      cormorant population.
CI  - Copyright 2010 Elsevier Inc. All rights reserved.
FAU - Iwata, Hisato
AU  - Iwata H
AD  - Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, 
      Matsuyama 790-8577, Japan. iwatah@agr.ehime-u.ac.jp
FAU - Nagahama, Nobumasa
AU  - Nagahama N
FAU - Kim, Eun-Young
AU  - Kim EY
FAU - Watanabe, Michio X
AU  - Watanabe MX
FAU - Sudo, Akiko
AU  - Sudo A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100422
PL  - United States
TA  - Comp Biochem Physiol C Toxicol Pharmacol
JT  - Comparative biochemistry and physiology. Toxicology & pharmacology : CBP
JID - 100959500
RN  - 0 (Polychlorinated Dibenzodioxins)
RN  - 0 (Receptors, Aryl Hydrocarbon)
RN  - 0 (Water Pollutants, Chemical)
RN  - 138391-32-9 (Aryl Hydrocarbon Receptor Nuclear Translocator)
RN  - EC 1.14.14.1 (Cytochrome P-450 CYP1A1)
SB  - IM
MH  - Animals
MH  - Aryl Hydrocarbon Receptor Nuclear Translocator/*metabolism
MH  - Birds/embryology/*metabolism
MH  - Cytochrome P-450 CYP1A1/*metabolism
MH  - Embryo, Nonmammalian/drug effects/metabolism
MH  - Environmental Exposure/analysis
MH  - Liver/*drug effects/enzymology/metabolism
MH  - Ovum/drug effects/metabolism
MH  - Polychlorinated Dibenzodioxins/*toxicity
MH  - Receptors, Aryl Hydrocarbon/*metabolism
MH  - Signal Transduction/drug effects
MH  - Water Pollutants, Chemical/*toxicity
EDAT- 2010/04/27 06:00
MHDA- 2010/07/07 06:00
CRDT- 2010/04/27 06:00
PHST- 2010/02/08 00:00 [received]
PHST- 2010/04/15 00:00 [revised]
PHST- 2010/04/15 00:00 [accepted]
PHST- 2010/04/27 06:00 [entrez]
PHST- 2010/04/27 06:00 [pubmed]
PHST- 2010/07/07 06:00 [medline]
AID - S1532-0456(10)00074-8 [pii]
AID - 10.1016/j.cbpc.2010.04.010 [doi]
PST - ppublish
SO  - Comp Biochem Physiol C Toxicol Pharmacol. 2010 Aug;152(2):224-31. doi: 
      10.1016/j.cbpc.2010.04.010. Epub 2010 Apr 22.