A comparison of basal and induced hepatic microsomal cytochrome P450 monooxygenase activities in the cynomolgus monkey (Macaca fascicularis) and man

Xenobiotica. 1999 May;29(5):467-82. doi: 10.1080/004982599238489.


1. The specific activities of hepatic microsomal cortisol 6beta-hydroxylase, coumarin 7-hydroxylase, S-mephenytoin 4'-hydroxylase and phenoxazone hydroxylase and the O-dealkylations of seven homologous alkoxyresorufins were < 3-fold different between the untreated (UT) cynomolgus monkey and man. 2. Heptoxy- and octoxyresorufin O-dealkylase, S-mephenytoin N-demethylase and dextromethorphan O-demethylase specific activities were > 6-fold higher, whereas tolbutamide hydroxylase was almost 5-fold lower in the UT monkey than in man. 3. Phenobarbitone induced (2-6-fold) coumarin 7-hydroxylase, cortisol 6beta-hydroxylase, S-mephenytoin N-demethylase, phenoxazone hydroxylase and benzyloxyresorufin O-dealkylase activities, but not the O-dealkylations of pentoxyresorufin or other alkoxyresorufins, in monkey. 4. Rifampicin induced (2-3-fold) cortisol 6beta-hydroxylase, S-mephenytoin 4'-hydroxylase, S-mephenytoin N-demethylase and tolbutamide hydroxylase activities, the O-dealkylations of methoxy-, ethoxy- and propoxyresorufin and CYP2C- and CYP3A-immunorelated proteins in monkey. 5. Dextromethorphan O-demethylase was significantly reduced by both phenobarbitone and rifampicin treatment in monkey. 6. Beta-naphthoflavone induced (8-39-fold) the O-dealkylations of several alkoxyresorufins, the greatest effect being on propoxyresorufin, but had no effect on the other activities measured in monkey. 7. Constitutive hepatic microsomal CYP2D6-immunorelated proteins were expressed at apparently much higher levels in monkey than in man.

Publication types

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

MeSH terms

  • Adult
  • Animals
  • Cytochrome P-450 Enzyme System / drug effects
  • Cytochrome P-450 Enzyme System / metabolism*
  • Enzyme Inhibitors / pharmacology
  • Female
  • Humans
  • Immunoblotting
  • Macaca fascicularis
  • Male
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / enzymology*
  • Middle Aged
  • Phenobarbital / pharmacology
  • Rifampin / pharmacology
  • Steroid Hydroxylases / drug effects
  • Steroid Hydroxylases / metabolism*
  • beta-Naphthoflavone / pharmacology


  • Enzyme Inhibitors
  • beta-Naphthoflavone
  • Cytochrome P-450 Enzyme System
  • Steroid Hydroxylases
  • Rifampin
  • Phenobarbital