Nuclear Receptor Regulation of Hepatic Cytochrome P450 Enzymes

Glossary Terms

Cytochrome P450 (CYP):

Family of hemeprotein monooxygenase enzymes that plays a central role in the oxidative metabolism of structurally diverse lipophilic steroids, fatty acids, drugs, and environmental chemicals. P450-catalyzed biotransformation of drugs is primarily carried out by 10–15 distinct human P450 enzymes, each encoded by a separate P450 gene.

Lithocholic acid:

3α-hydroxy-5β-cholanoic acid, a hepatotoxic and cholestatic secondary bile acid which is formed by bacterial dehydroxylation of primary bile acids in the intestine.

Orphan nuclear receptor:

Receptor protein belonging to the nuclear receptor superfamily whose physiological ligand has not been identified.

P450 induction:

The process whereby cellular and tissue levels of one or more cytochrome P450 enzymes are increased in response to treatment of cells, or a whole organism, with certain drugs or environmental chemicals referred to as P450 inducers. P450 induction leads to an increase in the cell’s...