Identification of glucocorticoid-inducible cytochromes P-450 in the intestinal mucosa of rats and man

J Clin Invest. 1987 Oct;80(4):1029-36. doi: 10.1172/JCI113156.


We used monoclonal antibodies and complementary DNAs (cDNAs) to glucocorticoid-inducible liver cytochromes P-450 in rats (P-450p) and in man (HLp) to search for related cytochromes in intestinal mucosa. In rat enterocytes, we found two dexamethasone-inducible proteins related to the steroid-inducible liver cytochromes P-450. Induction of these proteins in enterocytes was associated with increases in the amount of a P-450p-related messenger RNA and of erythromycin demethylase, an activity highly characteristic of P-450p and HLp. Similar studies on human jejunal enterocytes revealed a microsomal protein indistinguishable from HLp on immunoblots and an abundance of RNA hybridizing with HLp cDNA. In human enterocytes the specific concentration of the HLp-related cytochrome (measured immunochemically or as erythromycin demethylase activity) was similar to that found in human liver and could account for all of the CO-binding hemo-protein detected. We conclude that the intestinal mucosa contains prominent form(s) of cytochromes P-450 similar to liver cytochrome P-450p in their structure, function, and some regulatory characteristics.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Animals
  • Antibodies, Monoclonal
  • Cytochrome P-450 Enzyme System / biosynthesis*
  • DNA / analysis
  • Dexamethasone / pharmacology*
  • Enzyme Induction
  • Erythromycin / metabolism
  • Female
  • Humans
  • Intestinal Mucosa / enzymology*
  • Intestinal Mucosa / ultrastructure
  • Isoenzymes / biosynthesis*
  • Jejunum / enzymology
  • Jejunum / ultrastructure
  • Male
  • Microsomes / enzymology
  • Microsomes, Liver / enzymology
  • Middle Aged
  • Nucleic Acid Hybridization
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Inbred Strains


  • Antibodies, Monoclonal
  • Isoenzymes
  • RNA, Messenger
  • Erythromycin
  • Dexamethasone
  • DNA
  • Cytochrome P-450 Enzyme System