Sahi Jasminder, Grepper Susan, Smith Cornelia
Life Technologies ADME/Tox Division, Durham, NC 27703, USA.
Curr Drug Discov Technol. 2010 Sep;7(3):188-98. doi: 10.2174/157016310793180576.
The liver is the primary site of metabolism for most drugs. Its major roles include detoxification of the systemic and portal blood, and production and secretion of critical blood and biliary components. A number of liver-derived in vitro systems, such as slices, primary and immortalized hepatocytes, microsomes and S9 fractions are used to assess the metabolism and potential toxicity of new chemical entities. Over the past decade, primary hepatocytes have become a standard in vitro tool to evaluate hepatic drug metabolism, cytochrome P450 (P450) induction, and drug interactions affecting hepatic metabolism. While earlier, hepatocytes were used in suspension for metabolic stability evaluations, more recent studies have demonstrated the added value of using these over longer terms in primary culture. Primary hepatocyte cultures are particularly useful in the evaluation of low turn-over compounds. Hepatic transporter studies are recommended for drug candidates that are predominantly eliminated through the bile. An appropriate strategy is to use primary hepatocytes to assess uptake, followed by singly transfected cell lines to identify the specific transporter(s) involved. Primary hepatocytes can also be used to assess biliary clearance to enable improved hepatic clearance predictions. Newer technologies such as siRNA can be used to knock out specific transporters for more predictive evaluations of potential clinically-based drug-drug interactions. In vitro safety (toxicology) studies have historically been conducted using cell lines. There is increasing evidence that co-cultures of primary hepatocytes and Kupffer cells would be more predictive of the in vivo outcome, as this system provides the complete complement of drug metabolizing enzymes, transcription factors and cytokines necessary to get a more in vivo-like toxicological response. In this review, we will discuss standard and novel in vitro approaches for using primary hepatocytes to extrapolate clinical hepatic metabolism, transport and toxicity.
肝脏是大多数药物的主要代谢部位。其主要作用包括对体循环和门静脉血液进行解毒，以及产生和分泌关键的血液和胆汁成分。许多源自肝脏的体外系统，如切片、原代和永生化肝细胞、微粒体和S9组分，被用于评估新化学实体的代谢和潜在毒性。在过去十年中，原代肝细胞已成为评估肝脏药物代谢、细胞色素P450（P450）诱导以及影响肝脏代谢的药物相互作用的标准体外工具。早期，肝细胞以悬浮形式用于代谢稳定性评估，而最近的研究表明，在原代培养中长期使用这些细胞具有更大的价值。原代肝细胞培养在评估低周转率化合物方面特别有用。对于主要通过胆汁消除的候选药物，建议进行肝脏转运体研究。一种合适的策略是使用原代肝细胞评估摄取，然后使用单转染细胞系来鉴定所涉及的特定转运体。原代肝细胞还可用于评估胆汁清除率，以改进肝脏清除率预测。诸如siRNA等新技术可用于敲除特定转运体，以更具预测性地评估潜在的基于临床的药物-药物相互作用。体外安全性（毒理学）研究历来使用细胞系进行。越来越多的证据表明，原代肝细胞和库普弗细胞的共培养对体内结果更具预测性，因为该系统提供了获得更类似体内毒理学反应所需的完整药物代谢酶、转录因子和细胞因子。在本综述中，我们将讨论使用原代肝细胞推断临床肝脏代谢、转运和毒性的标准和新颖体外方法。
