Use of a fluorescent substrate for the selective quantification of rat CYP3A in the liver and the intestine

Jl, Michaud; Leblond, François A.; Naud, Judith; Boisvert, Caroline; Desbiens, Karine; Nicoll‐Griffith, Deborah A.; Pichette, Vincent

doi:10.1016/j.vascn.2006.07.002

Cited by 5 publications

(2 citation statements)

References 11 publications

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“…, that is specifically metabolized by rat CYP3A was used as previously reported (15). The substrate was added directly to the culture after removal of the culture media and replacement by Krebs buffer containing 12.5 mM HEPES for 30 min.…”

Section: Evaluation Of Cyp3a Activitymentioning

confidence: 99%

Effect of Hemodialysis on Hepatic Cytochrome P450 Functional Expression

Nolin

Naud

et al. 2008

J Pharmacol Sci

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Abstract. Cytochrome P450 (CYP) functional expression is reduced in uremia and normalized after restoration of kidney function via transplantation. The aim of this study was to evaluate the effect of conventional hemodialysis on the functional expression of CYP1A, 2C, and 3A. We also investigated the role of nuclear factor-κB (NF-κB) in CYP regulation during uremia. Primary cultures of normal rat hepatocytes were incubated with serum obtained from end-stage renal disease patients pre-and post-hemodialysis and healthy control subjects, in the presence and absence of the NF-κB inhibitor andrographolide. Uremic pre-hemodialysis serum caused significant reductions (P<0.01) in CYP1A (44%), 2C (27%), and 3A (35%) protein expression compared to control serum, while dialyzed serum (i.e., obtained immediately post-hemodialysis) had no effect. CYP1A2, 2C11, and 3A2 mRNA expression, as well as CYP3A activity, were similarly impacted by uremic serum and were improved to >80% of control values after hemodialysis. NF-κB inhibition nearly eliminated the effect of uremic serum on CYP functional expression. This is the first study to demonstrate that conventional hemodialysis acutely improves altered CYP functional expression observed in rat hepatocytes incubated with uremic human serum.

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Section: Evaluation Of Cyp3a Activitymentioning

confidence: 99%

Effect of Hemodialysis on Hepatic Cytochrome P450 Functional Expression

Nolin

Naud

et al. 2008

J Pharmacol Sci

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“…To evaluate the metabolic activity of CYP3A in 200 mg of microsomes prepared from whole-brain extract of CTL, CTL-PTX, CRF, and CRF-PTX rats, a selective fluorescent probe, 3-[(3,4-difluorobenzyl)-oxy]-5,5-dimethyl-4-[4-methylsulfonyl)phenyl]furan-2(5H)-one (DFB), specifically metabolized by rat CYP3A to 3-hydroxy-5, 5-dimethyl-4-[4-(methylsulfonyl) phenyl] furan-2(5H)-one (DFH) was used as previously reported (NicollGriffith et al, 2004;Michaud et al, 2007Michaud et al, , 2008. DFH fluorescence was determined on a cytofluorometer (Cytofluor 4000/TR; Perspective Biosystems, Framingham, MA) using appropriate wavelength (excitation filter: 360/40 nm; emission filter: 460/40 nm).…”

Section: Methodsmentioning

confidence: 99%

Effects of Chronic Renal Failure on Brain Cytochrome P450 in Rats

Naud

Harding

Lamarche

et al. 2016

Drug Metabolism and Disposition

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Chronic renal failure (CRF) impedes renal excretion of drugs and their metabolism by reducing the expression of liver cytochrome P450 (P450). Uremic serum contains factors, such as parathyroid hormone (PTH), that decrease liver P450s. The P450s are also involved in the metabolism of xenobiotics in the brain. This study investigates: 1) the effects of CRF on rat brain P450, 2) the role of PTH in the downregulation of brain P450s in CRF rats, and 3) the effects of PTH on P450s in astrocytes. Protein and mRNA expression of P450s were assessed in the brain of CRF and control (CTL) rats, as well as from CTL or CRF rats that underwent parathyroidectomy (PTX) 1 week before nephrectomy. CYP3A activity was measured using 3-[(3, 4-difluorobenzyl) oxy]-5, 5-dimethyl-4-[4-methylsulfonyl) phenyl] furan-2(5H)-1 metabolism in brain microsomal preparation.CYP3A protein expression was assessed in primary cultured astrocytes incubated with serum obtained from CRF or CTL rats or with PTH. Significant downregulations ( ‡40%) of CYP1A, CYP2C11, and CYP3A proteins were observed in microsomes from CRF rat brains. CYP3A activity reduction was also observed. CYP3A expression and activity were unaffected in PTX-pretreated CRF rats. Serum of PTX-treated CRF rats had no impact on CYP3A levels in astrocytes compared with that of untreated CRF rats. Finally, PTH addition to normal calf serum induced a reduction in CYP3A protein similar to CRF serum, suggesting that CRF-induced hyperparathyroidism is associated with a significant decrease in P450 drugmetabolizing enzymes in the brain, which may have implications in drug response.

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