Evaluation of CYP2D6 Protein Expression and Activity in the Small Intestine to Determine Its Metabolic Capability in the Japanese Population

CYP2D6 plays an important role in the metabolism of many drugs such as opioids and antidepressants. Polymorphisms of the CYP2D6 gene are widely observed in the Japanese population, and can affect the first-pass metabolism of orally administered drugs. Several CYP enzymes have been identified in the small intestine of Caucasians, but intestinal CYP enzymes have not been reported in the Japanese population, except for CYP3A4 and CYP2C19. In this...