Dose‐dependent biphasic effects of phenobarbital on growth and differentiation of primary culture rat hepatocytes

Miyazaki, Masahiro; Mars, Wendy M.; Michalopoulos, George K.; Namba, Masayoshi

doi:10.1111/jgh.1998.13.s1.78

Cited by 6 publications

(2 citation statements)

References 21 publications

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“…In order to reverse the decline of cytochrome P450 enzymes, well known inducers such as phenobarbital and DEX have been added as medium supplements, separately or in combination (LeCluyse et al, 1996, Miyazaki et al, 1998, Pichard-Garcia et al, 2002). The addition of phenobarbital, DEX and β-naphthoflavone to the culture medium of rat SCH preserves phase I and II enzyme levels almost equivalent to those in liver in vivo , as determined by gene expression and enzyme activity analysis (Kienhuis et al, 2007).…”

Section: Use Of Sandwich-cultured Hepatocytes To Investigate the Intementioning

confidence: 99%

Sandwich-cultured hepatocytes: anin vitromodel to evaluate hepatobiliary transporter-based drug interactions and hepatotoxicity

Swift¹,

Pfeifer²,

Brouwer³

2010

Drug Metabolism Reviews

335

297

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Sandwich-cultured hepatocytes (SCH) are a powerful in vitro tool that can be utilized to study hepatobiliary drug transport, species differences in drug transport, transport protein regulation, drug-drug interactions, and hepatotoxicity. This review provides an up-to-date summary of the SCH model, including a brief history of, and introduction to, the use of SCH, as well as methodology to evaluate hepatobiliary drug disposition. A summary of the literature that has utilized this model to examine the interplay between drug metabolizing enzymes and transport proteins, drug-drug interactions at the transport level, and hepatotoxicity as a result of altered hepatic transport also is provided.

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Section: Use Of Sandwich-cultured Hepatocytes To Investigate the Intementioning

confidence: 99%

Sandwich-cultured hepatocytes: anin vitromodel to evaluate hepatobiliary transporter-based drug interactions and hepatotoxicity

Swift¹,

Pfeifer²,

Brouwer³

2010

Drug Metabolism Reviews

335

297

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“…12 PB treatment in culture also is associated with decreased response to hepatocyte mitogens, including TGF␣ and HGF. 13 The mechanisms by which PB exerts all these complex effects in hepatocytes are not clear. The same pathways involved in changes in PB-induced gene expression may mediate these diverse effects.…”

mentioning

confidence: 99%

Phenobarbital regulates nuclear expression of HNF-4α in mouse and rat hepatocytes independent of CAR and PXR

Bell

Michalopoulos

2006

Hepatology

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Phenobarbital is a lipophilic molecule used as a sedative and antiepileptic drug that elicits a multitude of effects in the liver, including gross liver enlargement, hepatocyte hypertrophy, and induced expression of drug-metabolizing enzymes and other liver-specific genes. The constitutive androstane receptor (CAR; NR1I3) and to a lesser extent the pregnane X receptor (PXR; NR1I2) are responsible for mediating induction of many phenobarbital-responsive genes. However, CAR-mediated transcriptional control of some genes is critically dependent on hepatocyte nuclear factor 4 alpha (HNF-4␣; NR2A1), which itself regulates multiple liver-specific genes involved in hepatic growth, metabolism, and differentiation. We studied the effects of phenobarbital on HNF-4␣ expression in hepatocytes and provide evidence that HNF-4␣ nuclear expression is regulated in response to phenobarbital. Realtime polymerase chain reaction analyses revealed that HNF-4␣ mRNA is modestly upregulated by phenobarbital. In addition, nuclear expression of HNF-4␣ protein is significantly elevated 3 hours after the administration of phenobarbital in wild-type, CAR ؊/؊ , and CAR ؊/؊ /PXR ؊/؊ mice. In vitro analysis revealed that phenobarbital-induced HNF-4␣ expression is both time-and dose dependent. In addition, the phosphatase inhibitor okadaic acid and the Ca 2؉ /calmodulin-dependent protein kinase II inhibitor KN62 block nuclear induction of HNF-4␣ by phenobarbital. Furthermore, HNF-4␣ nuclear expression is enhanced by inhibition of cyclic AMP-dependent protein kinase A. In conclusion, induced nuclear expression of HNF-4␣ and CAR is an integral part of the phenobarbital response, aimed at coordinated regulation of genes involved in drug metabolism and detoxification as well as maintenance of liver function. (HEPATOLOGY 2006;44: 186-194.) P henobarbital (PB) is an antiepileptic drug and is the prototype of a large family of lipophilic PB-like compounds that have profound effects in the liver. Its effects on liver physiology are typified by hepatic hypertrophy, hyperproliferation of the smooth endoplasmic reticulum, and induction or repression of numerous genes, especially the genes of cytochrome P450 enzymes. 1-3 Hepatic hypertrophy induced by PB is mediated by a moderate increase in hepatocyte DNA synthesis and dramatic enlargement of individual hepatocytes. 4,5 Hepatic enlargement subsides after PB withdrawal and this decrease in liver size is mediated by hepatocyte apoptosis. 6 Liver regeneration in response to partial hepatectomy is markedly diminished in PB-treated rat and mouse livers. 7,8 PB is also one of the most effective liver tumor promoters in both rats and mice. The mechanism of liver tumor promotion by PB is not understood; however, there is evidence that PB affects EGF signaling. 9 . Furthermore, TGF␤1 receptors I, II, and III are specifically down-regulated in early neoplastic lesions following treatment with PB. 10,11 It has been hypothesized that the inhibition of DNA synthesis in normal hepatocytes gives a proliferative advant...

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Primary hepatocyte cultures for pharmaco-toxicological studies: at the busy crossroad of various anti-dedifferentiation strategies

et al. 2012

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Continuously increasing understanding of the molecular triggers responsible for the onset of diseases, paralleled by an equally dynamic evolution of chemical synthesis and screening methods, offers an abundance of pharmacological agents with a potential to become new successful drugs. However, before patients can benefit of newly developed pharmaceuticals, stringent safety filters need to be applied to weed out unfavourable drug candidates. Cost effectiveness and the need to identify compound liabilities, without exposing humans to unnecessary risks, has stimulated the shift of the safety studies to the earliest stages of drug discovery and development. In this regard, in vivo relevant organotypic in vitro models have high potential to revolutionize the preclinical safety testing. They can enable automation of the process, to match the requirements of high-throughput screening approaches, while satisfying ethical considerations. Cultures of primary hepatocytes became already an inherent part of the preclinical pharmaco-toxicological testing battery, yet their routine use, particularly for long-term assays, is limited by the progressive deterioration of liver-specific features. The availability of suitable hepatic and other organ-specific in vitro models is, however, of paramount importance in the light of changing European legal regulations in the field of chemical compounds of different origin, which gradually restrict the use of animal studies for safety assessment, as currently witnessed in cosmetic industry. Fortunately, research groups worldwide spare no effort to establish hepatic in vitro systems. In the present review, both classical and innovative methodologies to stabilize the in vivo-like hepatocyte phenotype in culture of primary hepatocytes are presented and discussed.

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Dose‐dependent biphasic effects of phenobarbital on growth and differentiation of primary culture rat hepatocytes

Cited by 6 publications

References 21 publications

Sandwich-cultured hepatocytes: anin vitromodel to evaluate hepatobiliary transporter-based drug interactions and hepatotoxicity

Sandwich-cultured hepatocytes: anin vitromodel to evaluate hepatobiliary transporter-based drug interactions and hepatotoxicity

Phenobarbital regulates nuclear expression of HNF-4α in mouse and rat hepatocytes independent of CAR and PXR

Primary hepatocyte cultures for pharmaco-toxicological studies: at the busy crossroad of various anti-dedifferentiation strategies

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