Gene Expression and DevelopmentExpression of CYP2A genes in human liver and extrahepatic tissues
Section snippets
Tissue samples
Surplus liver tissue was obtained from elective liver surgery at the Department of Surgery, University Hospital of Oulu, Finland. Nasal mucosa samples were obtained during surgery for diseases of nasal cavity or sinuses at the Department of Otolaryngology, University Hospital of Oulu. The nasal mucosa samples were taken from respiratory areas of the nasal cavity. Placental samples were from the repository kept at the Department of Pharmacology and Toxicology, University of Oulu. Uterine
Screening of CYP2A transcripts in liver and extrahepatic tissues
To ensure the quality and integrity of cDNA preparations, tissue samples were first analyzed for the presence of β-actin transcripts, and, where possible, for the presence of mRNA corresponding to CYP forms known to be expressed in each tissue. Only samples with detectable β-actin transcripts and positive CYP controls were subjected to assay with CYP2A-specific primers.
All three CYP2A mRNAs were detected in the liver by qualitative RT-PCR. Analysis of the PCR products in ethidium
Discussion
This study shows that all three CYP2A genes are transcribed in human liver, and that out of several extrahepatic tissues and organs studied, only nasal mucosa appears to contain detectable levels of CYP2A13 and CYP2A6 mRNA. It is well established that the RT-PCR technique can detect extremely small amounts of mRNA, often present at levels that may not be physiologically meaningful. On the other hand, a clear merit of this methodology is its high level of specificity, ensuring that only correct
Acknowledgements
We thank Risto Tuimala, Sirpa Rintala, and Teuvo Tammela (University of Tampere, Finland) for providing kidney samples, and Gerhard Bookjans and Peter Munzel (Institute of Toxicology, University of Tubingen, Germany) for providing duodenal samples. Pauli Wirta and Markku Pasanen helped in obtaining endometrium and placental samples. Financial support was provided by The Academy of Finland [Contracts 34555 and 29456].
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2020, Biochemical PharmacologyCitation Excerpt :The tissue expression pattern of P450 2A6 is similar in humans and marmosets. Human P450 2A6 mRNA is predominantly expressed in livers [40], whereas human P450 2A13 mRNA is abundantly expressed in lung, trachea, and nasal mucosa [41]. Coumarin 7-hydroxylation activities in marmoset livers increased when treated with phenobarbital and rifampicin [42], but P450 2A protein levels were unaffected, indicating that other P450 enzymes contribute to this reaction, similar to that is observed in rats [43].
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