CYP3A4

Résumé

thumb|Le cytochrome P450, famille 3, sous-famille A, polypeptide 4. Au centre, on aperçoit un groupement hème. Le Cytochrome P450 3A4, ou CYP3A4, est l'une des enzymes les plus importantes entrant en jeu dans le métabolisme des xénobiotiques par l'organisme humain. Il fait partie du système d'oxydases à fonction mixte. On le trouve principalement au niveau du foie. Parmi les cytochromes P450, le CYP3A4 est celui qui est impliqué dans la métabolisation du plus grand nombre de substrats. De ce fait, c'est aussi celui dont la concentration est la plus importante. Chez l'être humain, le gène codant CYP3A4 s'appelle lui aussi « CYP3A4 ». Le groupe de gènes des cytochromes P450 est localisé au niveau du chromosome 7, sur la bande q22.1. Fonction Le CYP3A4 fait partie de la super-famille d'enzymes du cytochrome P450. Ce sont des mono-oxygénases qui catalysent de nombreuses réactions permettant le métabolisme des médicaments, ainsi que la synthèse du cholestérol, des stéroïdes et

Source officielle

https://fr.wikipedia.org/wiki/CYP3A4

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Intracellular 'boosting' of darunavir using known transport inhibitors in primary PBMC

Ruben Hartkoorn

center dot Antiretroviral protease inhibitors such as lopinavir and saquinavir have been shown to be substrates of ABCB1. Co-administration with the potent ABCB1 and CYP3A4 inhibitor, ritonavir, has shown improved pharmacokinetics and subsequent therapeutic effects of protease inhibitors. Darunavir is a recently licensed protease inhibitor with potent antiretroviral effects but has yet to be characterized as a potential substrate for drug transporters.

2009

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Highly sensitive enzymatic MWCNTs-based biosensors for detection of abiraterone in human serum

Nima Aliakbarinodehi, Sandro Carrara, Giovanni De Micheli

A highly-sensitive enzymatic biosensor is successfully experimented for detection of abiraterone in human serum with significance in personalized medicine and point-of-care chemotherapy of patients with metastatic prostate cancer. The dynamic range and limit of the detection of the proposed biosensor coincides with the therapeutic range of abiraterone in circulatory system of patients (below 1 μM). An optimized label-free electrochemical biosensor was exploited in order to improve the performance of biosensor to detect low concentrations of abiraterone in human serum. Electroactive surface area has been increased by 4314 mm2 by MWCNTs nanostructuring respect to bare electrode to enhance the sensitivity. CYP3A4 protein was immobilized on MWCNTs as probe biomolecule. Electrochemical cyclic voltammetries demonstrated an inhibition effect on the CYP3A4, clearly observed as a diminished electrocatalytic activity of the enzyme. Dose-response behavior of biosensor in interaction with abiraterone in human serum samples is demonstrated that shows a dynamic range between zero and 1 μM and a detection limit of 230 nM.

2018

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A recent study with 69 Japanese liver transplants treated with tacrolimus found that the MDR13435 C >T polymorphism, but not the MDR12677 G >T polymorphism, was associated with differences in the intestinal expression level of CYP3A4 mRNA. In the present study, over 6 h, we measured the kinetics of a 75 microg oral dose of midazolam, a CYP3A substrate, in 21 healthy subjects genotyped for the MDR13435 C >T and 2677 G >T polymorphism. No statistically significant differences were found in the calculated pharmacokinetic parameters between the three 3435 C >T genotypes (TT, CT and CC group, respectively: Cmax (mean +/- SD: 0.30 +/- 0.08 ng/ml, 0.31 +/- 0.09 ng/ml and 0.31 +/- 0.11 ng/ml; Apparent clearance: 122 +/- 29 l/h, 156 +/- 92 l/h and 111 +/- 35 l/h; t1/2: 1.9 +/- 1.1 h, 1.6 +/- 0.90 h and 1.7 +/- 0.7 h). In addition, the 30-min 1'OH midazolam to midazolam ratio, a marker of CYP3A activity, determined in 74 HIV-positive patients before the introduction of antiretroviral treatment, was not significantly different between the three 3435 C >T genotypes (mean ratio +/- SD: 3.65 +/- 2.24, 4.22 +/- 3.49 and 4.24 +/- 2.03, in the TT, CT and CC groups, respectively). Similarly, no association was found between the MDR12677 G >T polymorphism and CYP3A activity in the healthy subjects or in the HIV-positive patients. The existence of a strong association between the activity of CYP3A and MDR13435 C >T and 2677 G >T polymorphisms appears unlikely, at least in Caucasian populations and/or in the absence of specific environmental factors.

2004

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