Mechanisms of Regulation of Cannabinoid Disposition

大麻是世界上使用最普遍的非法物质，孕妇使用大麻的人数最多。 女性越来越多。大约4%的孕妇使用大麻，尽管研究表明， 怀孕期间接触大麻对发育中的胎儿有不利影响。这是一个重大 公共卫生问题。然而，描述大麻使用对怀孕结果的影响受到了影响， 由于缺乏对大麻活性成分的药代动力学的了解， 四氢大麻酚（THC）在怀孕期间发生变化，由于缺乏可靠的生物标志物来量化 大麻的使用和暴露水平。事实上，目前，对个体间驱动过程的了解 THC处置的可变性在很大程度上是未知的。现有数据显示，货柜码头处理费主要由 CYP 2C 9，CYP 3A 4的贡献较小。几项研究表明，消除主要的 THC、11-OH-THC和11-去甲-羧基-THC的代谢物的代谢由UGT 1A酶介导。这很重要 在妊娠女性中THC处置的背景下，CYP 2C 9和UGT 1A酶已被证明 受雌二醇和糖皮质激素的调节，这是怀孕期间增加的主要女性激素。 基于这些数据，我们假设THC及其代谢物的清除率显著增加， 随着雌二醇和糖皮质激素浓度的增加。我们建议，这一增加可以 从体外人肝细胞和原代肠粘膜培养实验中预测的机制 激素治疗和创新的四氢大麻酚代谢实验在这个项目的第一部分，我们将 通过确定THC代谢和CYP 2C 9、CYP 3A 4的变化幅度来测试这些假设 处理人肝细胞和冻存肠 雌二醇和糖皮质激素。我们还将确定肝脏和肠道脂肪酸结合 蛋白质（FABPs）影响THC及其代谢物在体外的代谢和分布。THC已 THC及其代谢物是否与肝脏和肠道FABPs结合， 未知我们假设FABP结合指导THC代谢，并有助于大麻素 清除和传递给代谢酶。我们将在体外使用生物化学方法测试这一创新假设。 方法.在本建议的第二部分，我们将在临床研究中测试雌激素和皮质醇是否 诱导THC代谢和暴露。我们希望这些研究将为全面 人类妊娠期间THC处置的预测和建模。完成后，我们的研究将 提供有助于THC个体间变异性的过程的关键信息 药代动力学这些研究还将提供开创性的数据，以允许建模THC代谢组， 人血浆和尿液作为THC消耗量和消耗后时间的函数， 对人类THC暴露的可靠生物标志物的发展的影响。

Cannabis is the most commonly used illicit substance in the world, and the use of cannabis by pregnant women is increasing. Approximately 4% of all pregnant women use cannabis despite studies suggesting that cannabis exposure during pregnancy has negative consequences to the developing fetus. This is a significant public health concern. However, delineating the impact of cannabis use on pregnancy outcomes has suffered from lack of understanding of how the pharmacokinetics of the active component of cannabis, ∆9- tetrahydrocannabinol (THC) is altered during pregnancy, and from lack of a reliable biomarker to quantify cannabis usage and exposure levels. In fact, at present the knowledge of processes that drive inter-individual variability in THC disposition are largely unknown. Existing data suggests that THC is mainly cleared by CYP2C9 with a minor contribution from CYP3A4. Several studies have shown that the elimination of the major metabolites of THC, 11-OH-THC and 11-nor-carboxy-THC is mediated by UGT1A enzymes. This is important in the context of THC disposition in pregnant women as CYP2C9 and UGT1A enzymes have been shown to be regulated by estradiol and glucocorticoids, major female hormones that are increased during pregnancy. Based on this data, we hypothesize that the clearance of THC and its metabolites is significantly increased with increasing estradiol and glucocorticoid concentrations. We propose that this increase can be mechanistically predicted from in vitro human hepatocyte and primary intestinal mucosal culture experiments with hormone treatments and innovative THC metabolism experiments. In the first part of this project we will test these hypotheses by determining the magnitude of changes in THC metabolism and in CYP2C9, CYP3A4 and UGT1A isoform expression following treatment of human hepatocytes and cryopreserved intestinal mucosa with estradiol and glucocorticoids. We will also establish how hepatic and intestinal fatty acid binding proteins (FABPs) affect the metabolism and distribution of THC and its metabolites in vitro. THC has been shown to bind to brain FABPs, but whether THC and its metabolites bind to liver and intestinal FABPs is unknown. We hypothesize that FABP binding directs THC metabolism, and contributes to cannabinoid clearance and delivery to metabolic enzymes. We will test this innovative hypothesis in vitro using biochemical methods. In the second part of this proposal, we will test in a clinical study whether estrogens and cortisol induce THC metabolism and exposure. We expect that these studies will form the foundation for overall prediction and modeling of THC disposition during human pregnancy. When completed, our studies will provide critical information of the processes that contribute to inter-individual variability of THC pharmacokinetics. These studies will also provide seminal data to allow modeling of THC metabolome in human plasma and urine as a function of THC consumption and time after consumption, making a significant impact on development of reliable biomarkers of THC exposures in humans.