cytochrome P450

(redirected from Cytochrome P450 monooxygenase)

CYP11A1

A gene on chromosome 15q23-q24 that encodes a member of the cytochrome P450 superfamily of enzymes, which catalyse reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. CYP11A1 localises to the mitochondrial inner membrane and catalyses the conversion of cholesterol to pregnenolone, the first and rate-limiting step in the synthesis of the steroid hormones.

cytochrome P450

Abbreviation: CYP
A group of enzymes present in every type of cell in the body except red blood cells and skeletal muscle cells. They are important in metabolizing substances normally present in the body such as steroids, fat-soluble vitamins, fatty acids, prostaglandins, and alkaloids. The P450 enzymes also detoxify drugs and a great number of environmental pollutants, such as carcinogens present in tobacco smoke and charcoal-broiled meat, polychlorinated biphenyls, and dioxin. Specialized types of cytochrome P450 are involved in the synthesis of nitric oxide.
See also: cytochrome

cytochrome P450

A family of enzymes responsible for the detoxification and elimination of foreign substances including many drugs by hydroxylation and increasing their solubility. The group has been intensively studied because mutations of the cytochrome P450 gene have been found to be associated with a number of diseases including Addison's disease, liver cancer and Parkinson's disease. Cytochrome P450 can also interfere with drug treatment. Selective inhibitors of aromatase-specific cytochrome P450 have been developed to assist in the treatment of breast cancer.

cytochrome P450

hepatic microsome responsible for biotransformation of local anaesthetic agents into simpler chemical compounds
References in periodicals archive ?
We measured the response of 3 detoxifying enzyme systems: general esterase (EST), glutathione S-transferase (GST), and cytochrome P450 monooxygenase (P450).
Host plant species can passively affect the biochemistry of arthropods and one of the most important effects is on the detoxification enzymes involved in insecticide metabolism, including general esterases, glutathione S-transferases, and cytochrome P450 monooxygenases (e.
The work builds on one of the human liver's principal drug-metabolizing enzymes, cytochrome P450 monooxygenase.
The cytochrome P450 monooxygenase system is more affected by aging than any other metabolic pathway (3).
Several chapters focus on specific techniques, including use of cytochrome P450 monooxygenases, ionic liquids & supercritical CO2, thiamine-based enzymes, and Baeyer-Villiger monooxygenases.
BACKGROUND: Cytochrome P450 monooxygenases (CYP) play an important role in the defense against inhaled toxicants, and expression of CYP enzymes may differ among various lung cells and tissue compartments.
KEY WORDS: cytochrome P450 monooxygenases, metabolism, smoking, transcription factors, xenobiotic metabolizing enzymes.
We investigated the gene expression of 19 cytochrome P450 monooxygenases (CYPs) and 3 flavin-containing monooxygenases (FMOs), as well as uridine diphosphate glucuronosyltransferase (UGT) 2A1 (UGT2A1), epoxide hydrolase (EPHX1), glutathione-Stransferase (GST) A2 (GSTA2), GSTP1, and GSTM1 in lung cells obtained from bronchoalveolar lavage (BAL) fluid and in bronchial biopsies (BBs) of smokers (n = 8) and nonsmokers (n = 10).
Induction of nuclear transcription factors, cytochrome P450 monooxygenases, and glutathione S-transferase alpha gene expression in Aroclor 1254-treated rat hepatocyte cultures.
In insects, detoxification of xenobiotics is accomplished by 3 multigene families: carboxylesterases (CarE), cytochrome P450 monooxygenases (P450) and glutathione-S-transferases (GST) (Claudianos et al.

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