Laboratory Resource

20世纪70年代末，人们越来越认识到药代动力学在了解药物作用方面的重要性，因此需要为临床研究提供分析化学支持。尼尔·伯诺维茨发起了尼古丁和阿片类药物的药代动力学研究，里斯·琼斯发起了可卡因药代动力学和药效学的研究，主要得到了P50奖的支持。当时，我们的分析实验室有一名化学家、两名技术人员和两台气相色谱仪。 自那以来，许多需要分析化学支持的项目已经启动，我们的实验室工作人员已经 从3名增加到14名：两名博士研究化学家，九名研究助理和三名实验室助理。主要设备包括两台气相色谱仪、两台台式GC-MS系统、两个HPLC、三个三级四极LC-MS/MS系统和两个三级四极GC-MS/MS系统。 对实验室的支持来自P30中心、ROI和合同。 近年来，我们团队广泛使用了稳定同位素方法，我们相信这是创新的。 与放射性同位素标记的药物不同，稳定同位素标记的药物并不比 未贴标签的毒品。稳定的同位素，如氢同位素重氢，结合到药物分子中，就可以将标记的药物用作示踪剂。这是研究药物动力学和新陈代谢的有力工具，经常用于生物利用度研究。虽然天然药物通过其通常的途径给药，如口服、透皮或吸烟，但标记的药物同时通过静脉给药进行药代动力学表征。我们已经使用这项技术来确定吸烟造成的尼古丁摄入量(Benowitz等人。1991a)和无烟烟草(Jacob等人1999年)，经皮吸收尼古丁的生物利用度(Benowitz等人。)和通过各种途径给药的可卡因的生物利用度。我们使用稳定同位素方法研究了可卡因和乙醇的代谢处置，包括测定 将可卡因部分转化为可卡因(Jacob等人)1997年；Everhart等人。1998年)。使用稳定同位素方法学来确定鼻用和烟熏甲基苯丙胺的生物利用度(Harris等人。2003年)。我们对稳定同位素的使用正在继续并扩大。我们将利用标记的Frans-3‘-羟基可替宁来加深我们对尼古丁药物遗传学的理解，并更好地了解尼古丁代谢的种族差异的机制。可替宁-d4和代谢物比率将被用来研究青少年轻度吸烟者新陈代谢速度和成瘾发展之间的关联(Mark Rubinstein，MD，CA140216)。 我们使用稳定同位素方法来解决药物滥用领域特有的问题。其中一个问题是确定静脉注射尼古丁替代是否会抑制吸烟产生的尼古丁摄入量(Benowitz和Jacob，1990)。这导致得出结论，即使受试者无法完全戒烟，尼古丁替代药物，如透皮贴片(当时正在进行上市前的临床试验)也会抑制吸烟。我们用氚标记的可卡因给药来研究可卡因及其代谢物苯甲酰ecGonine在人头发中分布的时间过程。出于伦理原因，这些研究必须在可卡因滥用者中进行，标签药物的使用保证了随后在街头使用可卡因不会使结果无效(Henderson等人。1996年)。我们还使用标记尼古丁来研究尼古丁在头发和指甲中积累的时间过程，这似乎是尼古丁暴露的良好长期生物标志物。 这样的研究需要拥有合成和分析化学家的实验室，以及现代分析仪器。在使用稳定同位素时，广泛使用质谱学是必要的。适当标记的药物或代谢物可能无法在商业上获得，而我们在合成有机化学方面的能力已经被需要来制备稳定同位素标记的药物、代谢物和用于临床研究和分析的内部标准。在这一应用中，我们要求为实验室和行政人员提供支持，并为仪器提供支持，以保持和增强我们的分析化学能力。

The need for analytical chemistry support for clinical studies arose because of increased appreciation of the importance of pharmacokinetics in understanding drug action in the late 1970s. Neal Benowitz had initiated pharmacokinetic studies of nicotine and opioids and Reese Jones initiated studies of cocaine pharmacokinetics and pharmacodynamics, largely supported by a P50 award. At that time, our analytical laboratory consisted of a chemist, two technicians and two gas chromatographs. Since, many projects requiring analytical chemistry support were initiated and our laboratory staff has grown from three to 14: Two PhD Research Chemists, nine Staff Research Associates and three Laboratory Assistants. Major equipment includes two gas chromatographs, two desktop GC-MS systems, two HPLCs, three triple-stage quadrupole LC-MS/MS systems, and two triple-stage quadrupole GC-MS/MS systems. Support for the laboratories comes from the P30 Center, ROIs and contracts. In recent years, our group has made extensive, and we believe innovative, use of stable isotope methodology. Stable isotope-labeled drugs, unlike those labeled with radioisotopes, are no more hazardous than unlabeled drugs. A stable isotope, such as the hydrogen isotope deuterium, incorporated into a drug molecule allows the labeled drug to be used as a tracer. This is a powerful tool in studies of pharmacokinetics and metabolism, frequently used in bioavailability studies. While the natural drug is administered by its usual route, such as oral, transdermal, or by smoking, the labeled drug is simultaneously administered intravenously for pharmacokinetic characterization. We have used this technique to determine nicotine intake from smoking (Benowitz et al. 1991a) and from smokeless tobacco (Jacob et al. 1999), bioavailability of transdermal nicotine (Benowitz et al. 1991b) and bioavailability of cocaine administered by various routes. We have used stable isotope methodology to study the metabolic disposition of cocaine and ethanol, including determination of the fractional conversion of cocaine to cocaethylene (Jacob et al. 1997; Everhart et al. 1998). Stable isotope methodology was used to determine the bioavailablity of intranasal and smoked methamphetamine (Harris et al. 2003). Our use of stable isotopes is continuing and expanding. We will be utilizing labeled frans-3'-hydroxycotinine to further our understanding of nicotine pharmacogenetics and to better understand the mechanism of racial differences in nicotine metabolism.. Cotinine-d4 and the metabolite ratio will be used to study the association of the rate of metabolism and development of addiction in adolescent light smokers (Mark Rubinstein, MD, CA140216). We have used stable isotope methodology to address questions unique to the drug abuse area. One such question was to determine whether intravenous nicotine replacement would suppress nicotine intake from smoking (Benowitz and Jacob 1990). This led to the conclusion that nicotine replacement medications such as transdermal patches (at that time undergoing premarketing clinical trials) would suppress smoking even if subjects were unable to quit entirely. We have used deuterium-labeled cocaine administration to study the time course of distribution of cocaine and its metabolite benzoylecgonine into human hair. For ethical reasons, these studies had to be carried out in cocaine abusers, and the use of labeled drug guaranteed that subsequent street cocaine use would not invalidate the results (Henderson et al. 1996). We are also using labeled nicotine to study the time course of accumulation of nicotine into hair and nails, which appear to be good long term biomarkers of nicotine exposure. Such studies require laboratories with synthetic and analytical chemists, and modern analytical instruments. Extensive use of mass spectrometry is necessary when using stable isotopes. Suitably labeled drugs or metabolites may not be commercially available, and our capability in synthetic organic chemistry has been needed to prepare stable-isotope labeled drugs, metabolites, and internal standards for clinical studies and assays. In this application, we are requesting support for laboratory, and administrative staff, and for instrumentation to maintain and enhance our analytical chemistry capabilities.