Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"CYP3A"”.
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Propoxyphene, Norpropoxyphene, and Proadifen (SKF-525A) Are Mechanism Based Inhibitors of CYP3A4, CYP3A5, and CYP3A in Human Liver Microsomes
… are mechanism-based (irreversible) inhibitors of CYP3A, and to determine if propoxyphene and norpropoxyphene are reversible inhibitors of CYP3A. Mechanismbased inhibition is a type of irreversible inhibition that results from an inhibitor or its metabolite binding to an enzyme during drug …
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Content and Activity of Cytochrome P450 3A in Rat Brain Microsomes and Mitochondria
<p>The potential contribution of CYP3A in brain microsomes and mitochondria is crucial to designing appropriate therapeutic strategies and preventing toxicities. Until recently, there has been limited data reported in the literature with respect to CYP3A activity and its expression in the brain …
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Zytochrom P450 in Gehirn und Leber der Maus (Mus Musculus) Über die Funktion von P450 im Testosteronmetabolismus und die Beeinflussung durch das Antiepileptikum Phenytoin
… Inhibitoren zeigten eine Beteiligung von CYP3A-Enzymen am nachgewiesenen Metabolismus. Western und Northern blot Analysen bewiesen eine Phenytoin-induzierbare CYP3A-Expression in Mikrosomen und eine konstitutive Expression in Mitochondrien. Durch RT-PCR wurde die Expression von CYP3A11 und …
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Vitamin D Levels Affect Survival in a BCR-ABL Acute Lymphoblastic Leukemia Mouse Model but Do Not Cause Vitamin-Drug Interactions
… phenomenon that dietary components containing CYP3A inducers or inhibitors if co-administered with drugs that are CYP3A4 substrates lead to marked drug-drug interactions. Because vitamin D is known to regulate intestinal CYP3A expression and gut CYP3A expression plays an important role in …
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Determination of Absolute Protein Content of Hepatic CYP4F Enzymes in Human Liver Microsomes Using LC/MS/MS Methodology and Comparison with Immunoquantification and Enzyme Activity
… (parfuramidine (DB289), DB1230, fingolimod). The CYP3A subfamily of enzymes are known to metabolize a wide variety of physiologically and pharmaceutically important substances. The determination of the absolute enzyme protein content and the inter-individual variability in the expression of these …
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In vitro metabolism studies to inform physiologically-based pharmacokinetic modelling of mefloquine, ritonavir and proguanil
… found that the drug was metabolized mainly by CYP3A and CYP1A2. While mefloquine metabolism by CYP3A is widely reported, this is the first report of its metabolism by CYP1A2. Proguanil was found to be metabolized by a number of enzymes, namely CYP1A2, CYP2D6, CYP2C19 and CYP3A. This confirms …
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Genetic evaluation of cytochrome P450 expression in smoking and nonsmoking women
… some women.;3. The effect of menstrual phase on CYP3A expression in human endometrium. The CYP3A family consists of four closely related proteins. Of these, CYP3A3/4 is the most abundant P450 isoform and is responsible for metabolizing estrogen as well as a variety of therapeutic agents, whereas …
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Development and validation of liquid chromatography mass spectrometry (L/C/MS/MS) assay for the determination of plasma 4betahydroxycholestrol and cholesterol in HIV infected children in Africa
… been proposed as an endogenous biomarker forCYP3A4/5/7 activity. This may be useful in prediction of drug-drug interactions and other metabolic processes affected by regulators of CYP3A activity. The aim of this study was to develop and validate an LC/MS/MS assay for the determination of …
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Drug-drug interactions between antiretrovirals and bedaquiline
… liver by an enzyme called cytochrome P450 3A (CYP3A). The antiretrovirals nevirapine, efavirenz, and lopinavir/ritonavir (LPV/r) can affect the activity of this enzyme, and consequently affect the concentration of bedaquiline in the patient's blood. Nevirapine and efavirenz increase the …
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The influence of genetic polymorphisms and natural health products on drug metabolism
… on the activity of both P-gp and members of the CYP3A subfamily was also studied. Findings from this study suggest that the haplotype relationship of C3435T, G2677A/T and C1236T within the ABCB1 gene does not influence P-gp efflux activity or expression. Furthermore, some commonly consumed NHPs, …
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Stammesspezifische Unterschiede in der analgetischen Wirkung von Buprenorphin bei der Maus
… die Metabolisierung von Buprenorphin relevanten CYP3A Isozyme hinsichtlich der mRNA Expression, des Proteingehalts und der Aktivität, untersucht. Die verwendeten Mausstämme unterschieden sich deutlich in ihrer basalen Schmerzempfindlichkeit, wobei Balb/cJ Mäuse am sensitivsten und 129S1/SvImJ …
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Vitamin E : elucidation of the mechanism of side chain degradation and gene regulatory functions
… by ketoconozole, an inhibitor of CYP3A expression, whereas rifampicin, an inducer of CYP3A expression increased the metabolism of alpha-tocopherol. Although the degradation pathway is identical for all tocopherols and tocotrienols, there is a marked difference in the amount of the …
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Effect of berberine on in vitro metabolism of sulfonylureas: a herb-drug interactions study
… and tienilic acid as the inhibitors of CYP3A and CYP2D at 0.01 to 1.5 μM and 0.005 to 100 μM, respectively, with glyburide at 20 μM in 0.5 mg/mL microsomes and the NADPH regenerating system. The role of CYP2C in metabolism of gliclazide or glipizide was investigated by incubating these …
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Transporter-Targeted Prodrug Delivery to Improve Oral Bioavailability of Saquinavir
… the interaction between prodrugs and rat hepatic CYP3A enzymes, resulting in a relatively rapid clearance by CYP3A. Stereoselectivity is also observed in protein binding of prodrugs in rat plasma. Lower protein binding was obtained by LS, LLS and LDS but higher by DS, DDS and DLS as compared with …
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Mechanismus působení protinádorového léčiva ellipticinu v cílových tkáních jeho účinku
… b5 a zvýšení exprese a katalytické aktivity CYP3A. Podobně se i obsah a katalytická aktivita NADPH:cytochrom P450 reduktasy měnila v závislosti na premedikaci zvířat ellipticinem. Cytochrom P450 2S1...
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Selective Targeting of CYP3A5 Through Chemical and Genetic Approaches
… for various biological processes. In humans, the CYP3A subfamily is particularly critical for drug response. Within this family are CYP3A4 and CYP3A5, which collectively metabolize greater than half of all currently prescribed drugs. These promiscuous enzymes can bind a broad and structurally …
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Intestinal absorption barriers as modelled by p-glycoprotein and cytochrome p450 a34 in caco2 cells
… that there is no such co-regulation of P-gp and CYP3A4 in Caco-2 cells. However, there is evidence which suggests CYP3A metabolises mida_zolam into 1- and 4-hydroxymidazolam, the latter may possibly be a P-gp substrate and is transported extracellularly by P-gp, supporting the hypothesis of …
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The Design and Assembly of 3D Liver Mimetic Cellular Architectures
… three- to six-fold increased CYP1A1/2 and CYP3A enzymatic activity. Well-defined bile canaliculi were observed in only 3D hepatic constructs. In summary, these results indicate that the layered rLSEC-PEM-hepatocyte constructs can be used as liver models for future studies.
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Functional Expression of ABC Transporters at Blood-tissue Barriers: Relevance to Antiretroviral Drug Tissue Distribution
… and breast cancer resistance protein, using Cyp3a-/- (8-gene) knockout mouse model, and demonstrated that ritonavir can modestly enhance the accumulation of atazanavir in the brain and testes tissues. To better understand the role of HIV-1 viral proteins on the mRNA expression of ATP-binding …
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Characterisation of mammalian cytochrome P450 enzymes by their metabolic activities.
… P450 isoenzymes in the CYP1A, CYP2B and CYP3A subfamilies in rat liver microsomes. 3) Human liver microsomes from 15 different individuals metabolised harman to four metabolites, which were detected by normal phase HPLC following incubation with harman in the presence of NADPH and oxygen. …
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