These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Induction of two immunochemically related rat liver cytochrome P-450 isozymes, cytochromes P-450c and P-450d, by structurally diverse xenobiotics.
    Author: Thomas PE, Reik LM, Ryan DE, Levin W.
    Journal: J Biol Chem; 1983 Apr 10; 258(7):4590-8. PubMed ID: 6403529.
    Abstract:
    We have previously shown that purified rat liver cytochromes P-450c and P-450d share some but not all immunochemical determinants (Reik, L. M., Levin, W., Ryan, D.E., and Thomas, P.E. (1982) J. Biol. Chem. 257, 3950-3957). Antibody to cytochrome P-450d cross-reacts with cytochrome P-450c to form an immunoprecipitin band in the Ouchterlony test, but no detectable immunoprecipitin ring is formed in a radial immunodiffusion assay. However, the addition of purified cytochrome P-450c to purified cytochrome P-450d in the radial immunodiffusion assay alters the cytochrome P-450d standard curve. Appropriate corrections have been made for the interference of cytochrome P-450c in the immunoquantitation of cytochrome P-450d. Twelve structurally diverse xenobiotics have been examined for their capacity to modulate the levels of cytochrome P-450d, as well as cytochromes P-450a, P-450b, and P-450c, in rat liver microsomes. Five compounds (isosafrole, 3-methylcholanthrene, beta-naphthoflavone, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and phenothiazine) and the polychlorinated biphenyl mixture Aroclor 1254 are potent in vivo inducers of cytochrome P-450d (0.44-0.89 nmol of cytochrome P-450d/mg of microsomal protein). Control rats have low levels of this microsomal hemoprotein (0.04-0.05 nmol of cytochrome P-450d/mg of microsomal protein). Isosafrole induces cytochrome P-450d to a greater extent than cytochrome P-450c, Aroclor 1254 induces both hemoproteins to similar extents, and the remaining four compounds preferentially induce cytochrome P-450c relative to cytochrome P-450d. All of these structurally diverse compounds induce cytochromes P-450d and P-450c, suggesting that the inducibility of these cytochrome P-450 isozymes, but not cytochromes P-450a and P-450b, is linked.
    [Abstract] [Full Text] [Related] [New Search]