Open AccessExpression of Aryl Hydrocarbon Receptor (AhR) and Aryl Hydrocarbon Receptor Nuclear Translocator (Arnt) in Adult Rabbits Known to be Non‐Responsive to Cytochrome P ‐450 1A1 (CYP1A1) Inducers
Author(s) -
Takahashi Yoshiki,
Nakayama Kazuo,
Shimojima Tsukasa,
Itoh Susumu,
Kamataki Tetsuya
Publication year - 1996
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1996.0512r.x
Subject(s) - aryl hydrocarbon receptor nuclear translocator , aryl hydrocarbon receptor , cyp1b1 , cytochrome p450 , microbiology and biotechnology , cytochrome , aryl , receptor , biology , chemistry , messenger rna , endocrinology , medicine , biochemistry , transcription factor , enzyme , gene , alkyl , organic chemistry
Induction of aryl hydrocarbon hydroxylase by aryl hydrocarbons occurs only in neonatal rabbits and not in adult rabbits [Kahl, G. F., Friederich, D. E., Bigelow, S. W., Okey, A. B. & Nebert, D. W. (1980) Dev. Pharmacol. Ther 1 , 137–162], In the present study, we isolated cDNA clones encoding aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (Arnt) from adult rabbits. The deduced amino acid sequences of rabbit AhR and Arnt showed 80% and 94% identities with those of human AhR and Arnt, respectively. Rabbit AhR mRNA was predominantly expressed in the lung and liver. In contrast, rabbit Arnt mRNA was expressed at almost the same level in all tissues except for the heart, liver, and small intestine. Gel shift analysis showed that the AhR · Arnt complex could bind to the consensus xenobiotic‐responsive element, which indicates that AhR expressed in adult rabbit livers possessed binding activity to the consensus xenobiotic‐responsive element in vitro , although aryl hydrocarbons did not induce the activity of AHH in adult rabbits. We propose that the incapability of adult rabbits to induce cytochrome P ‐450 1A1 (CYP1A1) is caused by factors other than AhR and Arnt.