Dietary modulation of cytochrome P450 in the small intestinal epithelium

Pharmacology. 1991;43(1):36-46. doi: 10.1159/000138825.


Cytochrome P450 function was compared in rats maintained on cereal-based chow or a purified diet that simulates nutrient levels present in the chow. Ethoxycoumarin O-deethylase activity was increased in small intestine (15-fold), colon (2.5-fold) and liver (1.6-fold) by cereal chow. Ethoxyresorufin O-deethylase activity was also increased by cereal chow (75- and 2.5-fold in small intestine and liver, respectively). Cytochrome P450IAI, detected by Western blotting, was observed in intestinal microsomes isolated from chow-fed rats. These data underscore the importance of dietary considerations when evaluating studies of xenobiotics that undergo 'first pass' cytochrome P450-dependent metabolism in the small intestine.

Publication types

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

MeSH terms

  • 7-Alkoxycoumarin O-Dealkylase / metabolism
  • Animals
  • Benzoflavones / pharmacology
  • Colon / enzymology
  • Cytochrome P-450 CYP1A1
  • Cytochrome P-450 Enzyme System / metabolism*
  • Diet*
  • Enzyme Induction / drug effects
  • Epithelium / enzymology
  • Intestine, Small / enzymology*
  • Liver / enzymology
  • Male
  • Oxidoreductases / metabolism
  • Rats
  • Rats, Inbred Strains
  • beta-Naphthoflavone


  • Benzoflavones
  • beta-Naphthoflavone
  • Cytochrome P-450 Enzyme System
  • Oxidoreductases
  • 7-Alkoxycoumarin O-Dealkylase
  • Cytochrome P-450 CYP1A1