• The presence in orange juice of compounds that specifically inhibit the P-glycoprotein (P-gp) drug efflux transporter, but not the cytochrome P450 (CYP) isozyme CYP3A4, was investigated. (aspetjournals.org)
  • Induction of cytochrome P450 isozymes by simultaneous inhalation exposure of hens to n-hexane and methyl iso-butyl ketone (MiBK). (cdc.gov)
  • Induction of cytochrome-P-450 (P450) isozymes by n-hexane (110543) (hexane) and methyl-isobutyl-ketone (108101) (MIBK) was studied in hens. (cdc.gov)
  • The hens were killed at 29 days and the livers were removed and assayed for P450, benzphetamine-N-demethylase (BzND), ethoxyresorufin-O-deethylase (EROD), and cytochrome-c-reductase (cyt- c-red). (cdc.gov)
  • A reduced rate of lidocaine metabolism following tumescent liposuction may result from an inhibition of cytochrome P450 3A4 (CYP3A4) by sertraline (Zoloft) and flurazepam (Dalmane). (liposuction.com)
  • The specific cytochrome P450 enzyme responsible for the metabolism of flurazepam has not been identified. (liposuction.com)
  • Since 1994 there has been a rapid expansion of information about the specificity of hepatic microsomal enzymes of the cytochrome P450 family for the metabolism of different drugs. (liposuction.com)
  • Gender-dependent differences in cytochrome P450 activity, drug metabolism, drug elimination, and their clinical consequences are increasingly apparent. (asahq.org)
  • Cytochrome P450 3A4 is responsible for the biotransformation of myriad therapeutic drugs, toxins, and endogenous substrates, and it has the broadest substrate profile of any known P450 isoform. (asahq.org)
  • We investigated the metabolism of 1,8-cineole by liver microsomes of rats and humans and by recombinant cytochrome P450 (P450 or CYP) enzymes in insect cells in which human P450 and NADPH-P450 reductase cDNAs had been introduced. (unboundmedicine.com)
  • R.T. Williams , a Welsh pioneer in biotransformation studies, classified these pathways as phase I mainly catalysed by the cytochrome P450 system (oxidation, reduction, and hydrolysis reactions) and phase II (conjugation reactions). (clinicaleducation.org)
  • After a toxin undergoes phase I detoxification through cytochrome P450 enzymes, it is deemed an "intermediate metabolite" that must be further metabolised by phase II detoxification. (clinicaleducation.org)
  • The mechanism(s) responsible for the toxicity, carcinogenesis, cytochrome P450 (CYP) metabolism, groups of rats were pre- and the gender differences in these responses are not fully treated with the CYP inhibitor 5-phenyl-1-pentyne (PP) (100 mg/ understood. (cdc.gov)
  • After 70 d, liver pathology, serum alanine aminotransferase (ALT), biochemical markers of oxidative stress, liver fatty acid composition, cytochrome P450 2E1 (CYP2E1) expression and activity and cytochrome P450 4A (CYP4A) expression were assessed. (nih.gov)
  • The interindividual variability of cyclosporin A (CsA) pharmacokinetics might be explained by heterogeneity in the cytochrome P450 3A (CYP3A) subfamily. (transhumanist.ru)
  • The aim of the present study was to investigate the influence of the cytochrome P450 (CYP) 3A4/5 genotype in paediatric liver transplant recipients and donors, and the contribution of age and gender to tacrolimus disposition on the first day after transplantation. (transhumanist.ru)
  • Animals subjected to immunostimulatory conditions (sepsis) exhibit decreased total cytochrome P450 content and decreased P450-dependent drug metabolism. (silverchair.com)
  • Cytochrome P450 function is of clinical significance because it mediates the metabolism of some opioid and hypnotic drugs. (silverchair.com)
  • Administration of endotoxin increased plasma nitrite and nitrate concentrations, decreased total cytochrome P450 content, and decreased metabolism of ethylmorphine and midazolam. (silverchair.com)
  • It was originally thought to function primarily as a sensor of xenobiotic chemicals and also as the regulator of enzymes such as cytochrome P450s that metabolize these chemicals. (wikipedia.org)
  • The gill possesses many of the detoxifying enzymes found in the liver, and there are reports of induction of cytochrome P-450 and uridine diphosphoglucuronosyl transferase in the gills, but with the exception of the carboxylesterases, there is no information on the relevance of these enzymes to bioaccumulation. (astm.org)
  • Although drug interactions can involve enzymes such as glutathione S-transferases and uridine diphosphoglucuronyl transfereases (UGTs), most herbal drug interactions are related to oxidative metabolism by the cytochrome P-450 system (CYP) or by the effect of an herbal on the efflux drug transporter P-glycoprotein. (ijpsr.com)
  • Elevated levels of D-glucaric acid indicate induction of cytochrome P-450 enzymes (phase I) as a result of exposure to many xenobiotics, including pesticides, fungicides, petrochemicals, drugs, toluene, formaldehyde, styrenes and more. (nordicvms.com)
  • AFB 1 is metabolized by cytochrome P 450 enzymes to aflatoxin-8,9 epoxide which is then detoxified by the glutathione S- transferase system (GST). (hindawi.com)
  • 2-Butanol appears to be a particularly good alcohol substrate for the cytochrome P-450 dependent pathway of alcohol oxidation. (mssm.edu)
  • These results suggest that the ·OH-dependent and the cytochrome P-450 dependent pathways of alcohol oxidation by these microsomes do not display stereospecificity. (mssm.edu)
  • Pyrazole is oxidized to 4-hydroxypyrazole by rat liver microsomes in a cytochrome P-450-dependent reaction and this oxidation can be increased by prior treatment of rats with pyrazole, 4-methylpyrazole, or chronic ethanol feeding. (elsevierpure.com)
  • The induction pattern suggests that pyrazole may be an effective substrate for oxidation by P-450 IIE.1. (elsevierpure.com)
  • Experiments were carried out to evaluate the ability of anti-3a IgG to inhibit pyrazole oxidation by microsomes from controls and from rats treated with inducers of P-450 IIE.1. (elsevierpure.com)
  • Rates of pyrazole oxidation were highest with microsomes from rats treated with the inducer of P-450 IIE.1 and lowest with pair-fed controls or rats treated with phenobarbital. (elsevierpure.com)
  • The anti-3a IgG-sensitive rate of pyrazole oxidation was increased 4- to 5-fold after treatment of rats with pyrazole, 4-methylpyrazole, or ethanol, indicating that the increased oxidation of pyrazole caused by these agents is due to induction of P-450 IIE.1. (elsevierpure.com)
  • Clejan, LA, Koop, DR & Cederbaum, AI 1989, ' Sensitivity of the rat liver microsomal oxidation of pyrazole to antibody raised against the ethanol-inducible rabbit liver cytochrome P-450 isozyme ', Drug Metabolism and Disposition , vol. 17, no. 6, pp. 694-698. (elsevierpure.com)
  • Pre-treatment of rats or mice with 3-methylcholanthrene results in a small increase in total hepatic cytochrome P-450 and a significant change in the spectral characteristics of the isolated microsomes. (psu.edu)
  • Regional hepatic CYP1A1 and CYP1A2 induction with 2,3,7,8-tetrachlorodibenzo- p -dioxin evaluated with a multicompartment geometric model of hepatic zonation. (cdc.gov)
  • Changes in dietary fat composition did not alter ethanol metabolism or CYP2E1 induction, but hepatic CYP4A levels increased markedly in rats fed the saturated fat diet. (nih.gov)
  • The hepatic nuclear fraction isolated from 3-methylcholanthrene (MC)-treated rats contained enhanced levels of cytochrome P-450 and aryl hydrocarbon hydroxylase [benzo(a)pyrene (BP) monooxygenase], whereas the activities of epoxide hydrase and reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase and the concentration of cytochrome b5 were not altered. (lookformedical.com)
  • A liver microsomal cytochrome P-450 monooxygenase capable of biotransforming xenobiotics such as polycyclic hydrocarbons and halogenated aromatic hydrocarbons into carcinogenic or mutagenic compounds. (curehunter.com)
  • Chronic alcohol use can increase the dose requirements for general anesthetics, either because of induction/stimulation of the microsomal ethanol-oxidizing system (cytochrome P-450 system), or through the development of cross tolerance to other central nervous system drugs. (theanesthesiaconsultant.com)
  • Selective inactivation by chloramphenicol of the major phenobarbital-inducible isozyme of dog liver cytochrome P-450. (aspetjournals.org)
  • Chloramphenicol (CAP) is a potent and effective mechanism-based inactivator of the major phenobarbital (PB)-inducible isozyme of dog liver cytochrome P-450 (PBD-2) in vitro. (aspetjournals.org)
  • this P-450 isozyme is recognized by antibody (anti-3a IgG) raised against the ethanol-inducible P-450 in rabbits. (elsevierpure.com)
  • Hence, 2-butanol appears to be a very good alcohol substrate for the ethanol-inducible cytochrome P-450. (mssm.edu)
  • Stereochemical studies may be of value in elucidating the mechanism and the identification of the ethanol-inducible cytochrome P-450. (mssm.edu)
  • Subfractionation of the microsomes indicates that at least two different populations of cytochrome P-450 occur, each being characteristic of microsomes of different densities. (psu.edu)
  • Covalent binding of [14C]CAP to dog liver microsomes in vitro is increased 5.5 times by PB induction. (aspetjournals.org)
  • Microsomes have the potential to oxidize alcohols by two pathways, one dependent on hydroxyl radicals (·OH) and the other dependent on cytochrome P-450 in which ·OH does not seem to be involved. (mssm.edu)
  • Thus, the stereochemical preference displayed by microsomes from chronic alcohol fed rats may be due to the induction of a particular cytochrome P-450. (mssm.edu)
  • Most of this increment reflected an increased rate of metabolism by the cytochrome P-450 pathway. (mssm.edu)
  • A multicompartment geometric model of the liver in relation to regional induction of cytochrome P450s. (cdc.gov)
  • In vitro studies based on MCF-7 cell proliferation and induction of vitellogenin in primary culture of rainbow trout hepatocytes. (cdc.gov)
  • 5.Danan G, Descatoire V, Pessayre D. Self-induction by erythromycin of its own transformation into a metabolite forming an inactive complex with reduced cytochrome P-450. (webmd.com)
  • In a reconstituted system containing PBD-2, CAP causes a time- and NADPH-dependent irreversible loss of 7-ethoxycoumarin deethylase activity, with no loss of spectrally detectable cytochrome P-450. (aspetjournals.org)
  • Induction of the P-450 system by exogenous agents causes ALA accumulation and predisposes patients to acute attacks of porphyria. (medscape.com)
  • Chloride cell proliferation and ATPase induction are frequently reported results of metal exposure. (astm.org)
  • Inactivation is enhanced by cytochrome b5, and, in the presence of cytochrome b5, the concentration of CAP at which the rate constant for inactivation is half-maximal (Kl) and the maximal rate constant for inactivation (Kinact) are 5 microM and 1.2 min-1, respectively. (aspetjournals.org)
  • ALA synthetase activity is also closely associated with cytochrome P-450 activity. (medscape.com)
  • Induction of the alcohol-inducible form of cytochrome P-450 by nitrogen-containing heterocycles: effects on pyridine N-oxide production. (nih.gov)
  • Since commencing my role as a professor in a newly established Department of Pharmacodynamics and Molecular Genetics at the School of Pharmacy, Iwate Medical University, on April 1, 2007, my research has focused on modifying gene expression of cytochrome P-450 (CYP) in established human colon cancer cells. (bvsalud.org)
  • These cytochrome P-450 fractions differ from those isolated from control or phenobarbital-treated animals. (psu.edu)
  • Histological observation confirmed the induction of tumour in Group II animals and complete regression of tumour in Group III animals. (hindawi.com)
  • These results suggest that activation and detoxification of benzo(a)pyrene may be species and tissue variable, and susceptibility and resistence to malignant transformation may be predicted on induction of a fortuitous combination of intermediate metabolic steps. (lookformedical.com)
  • Since cortisol controls ATPase induction, the proliferation of chloride cells may be part of a general stress response. (astm.org)
  • Isoniazid (INH) is a selective inducer of cytochrome P‐450 isozymes that are involved in the biotransformation of organohalogen anesthetics. (arizona.edu)
  • The predominant mechanism for this interaction is the inhibition of cytochrome P -450 3A4 in the small intestine, resulting in a significant reduction of drug presystemic metabolism. (nature.com)
  • Cytochrome P-450 3A4 (CYP3A4), the predominant cytochrome P-450 expressed in adult human liver, is subject to transcriptional induction by a variety of structurally unrelated xenobiotics, including the antibiotic rifampicin. (aspetjournals.org)
  • These studies establish that P-450p is the predominant P-450 isozyme induced by clotrimazole, miconazole, and ketoconazole. (vcu.edu)
  • Rifampicin-inducible transcription of the reporter gene was observed only with the longest construct, which encompassed bases −13000 to +53 of CYP3A4 (3-fold induction). (aspetjournals.org)
  • Our results provide evidence for the existence of a potent enhancer module, 8 kb distal to the transcription start point, which mediates the transcriptional induction of CYP3A4 by activators of hPXR. (aspetjournals.org)
  • The human P-450 3A subfamily contains three functional members: CYP3A4, CYP3A5, and CYP3A7. (aspetjournals.org)
  • Induction of CYP3A4 expression by rifampicin and other xenobiotics underlies many reported drug interactions and is of considerable importance for patients subject to combination drug therapy such as for HIV/AIDS ( Michalets, 1998 ). (aspetjournals.org)
  • 13. Dexamethasone accelerates degradation of aryl hydrocarbon receptor (AHR) and suppresses CYP1A1 induction in placental JEG-3 cell line. (nih.gov)
  • Coadministration of lopinavir/ritonavir and phenytoin results in two-way drug interaction through cytochrome P-450 induction. (childrensmercy.org)
  • The genotoxic impact of carcinogen exposure is heavily influenced by a complex array of metabolic pathways, which includes the cytochrome P 450 (CYP) enzyme system. (biomedcentral.com)
  • 5. Dephosphorylation of Sp1 at Ser-59 by protein phosphatase 2A (PP2A) is required for induction of CYP1A1 transcription after treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin or omeprazole. (nih.gov)
  • 6. Responsiveness of the adult male rat reproductive tract to 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: Ah receptor and ARNT expression, CYP1A1 induction, and Ah receptor down-regulation. (nih.gov)
  • 17. Signal transduction-mediated CYP1A1 induction by omeprazole in human HepG2 cells. (nih.gov)
  • Oxidative reactions are mostly carried out by a group of monooxygenases in the liver, called as cytochrome P-450 , NADPH, cytochrome P-450 reductase and molecular O2. (slideshare.net)
  • Liver enzyme (cytochrome P-450) induction reduces the efficacy of the combined oral contraceptive pill, combined contraceptive patch, combined contraceptive vaginal ring and progestogen-only contraceptive pill and this may place women at greater risk of unplanned pregnancy. (patient.info)
  • 12. Induction of cytochrome P-450 1A1 by omeprazole in human HepG2 cells is protein tyrosine kinase-dependent and is not inhibited by alpha-naphthoflavone. (nih.gov)
  • Differential increases in specific P-450 mRNAs and proteins resulted from treatment of rats with these imidazol e antifungal drugs, suggesting that multiple cellular events are involved t heir mechanism of P-450 induction. (vcu.edu)
  • At high cytochrome P-450 levels, bleomycin-induced gene conversion was enhanced in both strains although mitochondrial functionality showed a detoxicant role while cellular GSH content decreased the induction of convertants only in the respiratory proficient strain. (unipr.it)
  • Identification and characterization of novel sequence variations in the cytochrome P4502D6 (CYP2D6) gene in African Americans. (childrensmercy.org)
  • Cytochrome P4502D6 (CYP2D6) gene locus heterogeneity: characterization of gene duplication events. (childrensmercy.org)
  • The anesthetic plan involves general endotracheal anesthesia with intravenous induction, an inhaled anesthetic for maintenance of anesthesia, an opioid agonist for analgesia, and a neuromuscular blocking agent for skeletal muscle relaxation. (medscape.com)
  • Induction of CYP2E1 is proposed as a mechanism augmenting the formation of reactive paracetamol metabolites [ 7 ]. (hindawi.com)
  • Based on these results and previous evidence concerning the regulation of Cyp2a5, we have identified several pathophysiological changes including altered energy homeostasis, hyperbilirubinemia, ER stress, and altered redox status that are associated with CYP2A5 overexpression and may represent potential stimuli for the induction of Cyp2a5. (nih.gov)
  • Purification of cholesterol 7 alpha-hydroxylase and the immunochemical evidence for the induction of cholesterol 7 alpha-hydroxylase by cholestyramine and circadian rhythm. (omeka.net)
  • The genotoxic effects of the antiblastic drug bleomycin were studied in the D7 strain of Saccharomyces cerevisiae and on its derivative mitochondrial mutant r° at different cellular concentrations of two drug metabolizing systems, glutathione (GSH) and cytochrome P-450. (unipr.it)
  • In the D7 strain, petite mutant induction was also detected. (unipr.it)
  • The reasons for the lack of induction are discussed. (ru.ac.za)
  • In conclusion, expression of the P-450p family of cytochromes P-450 in rat liver is under complex regulatory control and is subject to modulation by clinically useful drugs. (vcu.edu)
  • This is important due to the role of the mitochondrial genome in cancer induction, ageing and degenerative diseases. (unipr.it)
  • 1989. Cellular alterations and enhanced induction of cleft palate after coadministration of retinoic acid and TCDD. (cdc.gov)
  • Treatment with various chemicals resulted in differential induction of the 1G8- and 13-7-10-reactive proteins, demonstrating distinct regulatory features of these immunochemically-related proteins. (vcu.edu)
  • However, normal levels of Cyp1a-1 induction occurred in the livers of the same mice. (utmb.edu)
  • The change of mitochondrial morphology and the loss of mitochondrial membrane potential (MMP) were observed during the induction. (spandidos-publications.com)
  • Immunosuppressive drugs can be classified as induction therapies, maintenance therapies and antirejection therapies. (medscape.com)
  • While searching for novel inducers of the P-450p family, the imidazole antifungal drug clot rimazole was found to significantly increase total cytochrome P-450. (vcu.edu)
  • [ 7 ] Nevertheless, desflurane should not be used as the sole agent for anesthetic induction in patients with coronary artery disease or any patient in whom increases in heart rate or blood pressure are undesirable. (medscape.com)
  • Even though INH pretreatment enhanced oxidative halothae biotransformation and subsequent hepatotoxicity, sensitivity of guinea pigs to the deleterious actions of INH would contraindicate its use as a cytochrome P‐450 induction agent. (arizona.edu)