Species differences in hepatocyte induction of CYP1A1 and CYP1A2 by omeprazole

1 Omeprazole, a proton pump inhibitor therapeutically administered for the treatment of gastric ulcers, induces the expression of cytochromes P4501A1/2 (CYP1A1/2) through transcriptional activation mediated by the Ah (dioxin)-receptor. Primary cultures of hepatocytes isolated from rabbit, rat, mouse and human livers were compared for CYP1A1/2 mRNA inducibility by omeprazole (1 to 100 μM). 2 Primary cultures of human hepatocytes were the most sensitive to the inducing effects of omeprazole. Rabbit hepatocytes were the only other cells studied that showed induced CYP1A1/2 mRNA expression from a concentration lower than 100 μM (i.e., 10 μM). Rat hepatocytes were the least sensitive to omeprazole induction. The response of mouse hepatocytes to omeprazole treatment was variable, with CYP1A1/2 mRNA expression being induced in only two of the three cultures examined. 3 Differences in the time dependence of CYP1A1/2 mRNA expression were observed between species. In general, after treatment of hepatocytes with omeprazole the levels of CYP1A1 mRNA peaked prior to that of CYP1A2 mRNA. 4 Due to the interspecific variability of CYP1A mRNA inducibility by omeprazole, we conclude that human hepatocytes in culture are probably the only appropriate animal model for prediction of CYP1A induction in humans.

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Striking Species Difference in the Contribution of Concentrative Nucleoside Transporter 2 to Nucleoside Uptake between Mouse and Rat Hepatocytes

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00010-10 ◽

2010 ◽

Vol 54 (7) ◽

pp. 3035-3038 ◽

Cited By ~ 4

Author(s):

Tomomi Furihata ◽

Yukina Fukuchi ◽

Minami Iikura ◽

Misato Hashizume ◽

Atsushi Miyajima ◽

...

Keyword(s):

Mrna Expression ◽

Species Difference ◽

Nucleoside Analogs ◽

Rat Hepatocytes ◽

Activity Levels ◽

Nucleoside Transporter ◽

Concentrative Nucleoside Transporter ◽

Uptake Activity ◽

Mouse Hepatocytes ◽

Nucleoside Uptake

ABSTRACT Concentrative nucleoside transporter 2 (CNT2) (encoded by the SLC28A2 gene) transports various antiviral or antitumor purine nucleoside analogs to be involved in their pharmacokinetics and pharmacological actions. The results of our study showed that mouse hepatocytes hardly expressed CNT2 mRNA and no CNT2-dependent nucleoside uptake was observed, while rat hepatocytes exhibited high CNT2-dependent nucleoside uptake activity levels with abundant CNT2 mRNA expression. We concluded that CNT2 contributes considerably to nucleoside uptake in rat hepatocytes but not in mouse hepatocytes.

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Effects of prototypical drug-metabolizing enzyme inducers on mRNA expression of housekeeping genes in primary cultures of human and rat hepatocytes

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2006.06.012 ◽

2006 ◽

Vol 346 (3) ◽

pp. 1033-1039 ◽

Cited By ~ 25

Author(s):

Masuhiro Nishimura ◽

Akiko Koeda ◽

Emako Suzuki ◽

Takefumi Shimizu ◽

Yuichi Kawano ◽

...

Keyword(s):

Mrna Expression ◽

Primary Cultures ◽

Rat Hepatocytes ◽

Housekeeping Genes ◽

Drug Metabolizing Enzyme ◽

Metabolizing Enzyme ◽

Enzyme Inducers

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Effect of Aflatoxin B1 on Nuclear Receptors PXR, CAR, and AhR and Their Target Cytochromes P450 mRNA Expression in Primary Cultures of Human Hepatocytes

International Journal of Toxicology ◽

10.1177/1091581811422453 ◽

2011 ◽

Vol 31 (1) ◽

pp. 86-93 ◽

Cited By ~ 31

Author(s):

Imen Ayed-Boussema ◽

Jean-Marc Pascussi ◽

Patrick Maurel ◽

Hassen Bacha ◽

Wafa Hassen

Keyword(s):

Mrna Expression ◽

Aflatoxin B1 ◽

Messenger Rna ◽

Animal Feed ◽

Cytochromes P450 ◽

Primary Cultures ◽

Constitutive Androstane Receptor ◽

Pregnane X Receptor ◽

Receptor Activation ◽

Human Hepatocytes

Aflatoxin B1 (AFB1), one of the most common mycotoxins found in human foods and animal feed, is principally hepatotoxic and hepatocarcinogenic. The aim of the present study was to explore the effect of AFB1 on messenger RNA (mRNA) expression of pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AhR) and some of their target cytochromes using primary cultures of human hepatocytes. Our results showed that AFB1, at noncytotoxic increasing concentrations, caused a significant upregulation of cytochrome P 2B6 (CYP2B6), CYP3A5, and to a lesser extent CYP3A4 and CYP2C9. Pregnane X receptor and CAR mRNA expression increased in the 3 treated livers. Aflatoxin B1 was found also to induce an overexpression of CYP1A1 and CYP1A2 genes accompanied by an increase in AhR mRNA expression. These findings suggest that AFB1 could activate PXR, CAR, and AhR; however, further investigations are needed to confirm nuclear receptor activation by AFB1.

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Transfection Protocol for Primary Hepatocytes ( Rat Hepatocytes, Mouse Hepatocytes and Human Hepatocytes) in Targefect Handbook of Transfection Protocols

Protocol Exchange ◽

10.1038/protex.2011.226 ◽

2011 ◽

Author(s):

rampyari walia ◽

Rampyari Walia

Keyword(s):

Rat Hepatocytes ◽

Human Hepatocytes ◽

Primary Hepatocytes ◽

Transfection Protocol ◽

Mouse Hepatocytes

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Regulation of 11 beta-hydroxysteroid dehydrogenase type 1 in primary cultures of rat and human hepatocytes

Journal of Endocrinology ◽

10.1677/joe.0.1560159 ◽

1998 ◽

Vol 156 (1) ◽

pp. 159-168 ◽

Cited By ~ 54

Author(s):

ML Ricketts ◽

KJ Shoesmith ◽

M Hewison ◽

A Strain ◽

MC Eggo ◽

...

Keyword(s):

Growth Factor ◽

Reductase Activity ◽

Primary Cultures ◽

Rat Hepatocytes ◽

Human Hepatocytes ◽

Mrna Levels ◽

Cultured Hepatocytes ◽

Specific Regulation ◽

Species Specific

Two isozymes of the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) are responsible for the interconversion of the active glucocorticoid, cortisol in man, (corticosterone in the rodent), to the inactive 11-keto metabolite, cortisone (11-dehydrocorticosterone). We have examined the regulation of type 1 11 beta-HSD (11 beta-HSD1) using primary cultures of rat and human hepatocytes, both of which express only 11 beta-HSD1. Only 11 oxo-reductase activity could be demonstrated in cultured hepatocytes (apparent Km for cortisone 382 +/- 43 nM in human hepatocytes, apparent Km for 11-dehydrocorticosterone 14.6 +/- 1.5 microM in rat hepatocytes). There exists a marked discrepancy between 11 beta-HSD oxo-reductase activity and 11 beta-HSD1 mRNA levels in cultured human hepatocytes and human liver. Thus oxo-reductase specific activity is much higher in the cultured hepatocytes (7.2 +/- 0.01 nmoles cortisol/mg/h vs 0.89 +/- 0.06 for whole liver homogenates) whilst the converse is true for steady state 11 beta-HSD1 mRNA levels (0.78 +/- 0.02 vs 1.94 +/- 0.07 in whole liver, 11 beta-HSD1/18S expressed as arbitrary units). Carbenoxolone has a significant inhibitory effect on 11 oxo-reductase activity in both rat and human hepatocytes. However, there is clear species-specific regulation of 11 oxo-reductase activity by thyroid hormone (tri-iodothyronine (T3)), which increases 11 oxo-reductase activity in rat hepatocytes but has no effect on activity in human hepatocytes, and progesterone which inhibits activity in human hepatocytes, but has no effect on activity in rat hepatocytes. Neither T3 nor progesterone altered 11 beta-HSD1 mRNA levels. A series of growth factors (hepatocyte growth factor, epidermal growth factor, basic fibroblast growth factor, transforming growth factor beta 1) were without effect on 11 oxo-reductase activity in cultured rat hepatocytes. In contrast to homogenates of human liver, cultured hepatocytes express only 11 beta-HSD oxo-reductase activity. This is inhibited by carbenoxolone and shows species-specific regulation by T3 and progesterone. Growth factors do not appear to regulate activity or expression of 11 beta-HSD1. The discrepant enzyme activity data and 11 beta-HSD1 mRNA expression in hepatocytes and whole liver could reflect unstable 11 beta-HSD1 oxo-reductase activity or, alternatively, an additional 11 beta-HSD oxo-reductase isoform in cultured hepatocytes.

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