Clarification of organ specific transport mechanism of druge and its application to regulation of pharmacokinetics and pharmacodynamics

本课题旨在从器官、细胞、分子和基因等水平阐明药物的器官特异性转运，为药物的药代动力学和药效学调控提供新的方法。本课题由14名调查人员组成，历时两年，研究结果如下：对参与口腔和肠道吸收和分泌、肾脏分泌和重吸收、肝吸收和胆道分泌以及脑内流和外排转运的转运体的分子生物学特性进行了研究。明确了PepT1、PepT2、MCT1、cMOAT、OAT-K1和OCT2转运蛋白的克隆及其转运功能和组织分布。p -糖蛋白在肠道和血脑屏障（BBB）中作为亲脂性异种生物的运输屏障。多肽被证实被吸附介导的内吞所吸收……更多的是在血脑屏障处被输送到大脑。2.通过糖基化、Peyer’s patches内吞作用、离子电泳方法和通过吸收增强剂打开紧密连接来改善药物的吸收。3.肝细胞和库普弗细胞对分离肝素的摄取受到清道夫受体介导和血浆蛋白介导机制的调节。利用半乳糖化技术实现了药物、蛋白质和基因的肝脏特异性递送。活性氧，如超氧化物和一氧化氮（NO），在多种疾病的发病机制中发挥着重要作用。为了克服氧化应激，合成了位点定向的SOD衍生物，成功地将其传递给靶向细胞。利用“血管靶向”抗体识别肿瘤内皮细胞，为实体瘤的抗体治疗提供了一条有吸引力的途径。4.以α - 1肾上腺素受体为模型，成功克隆了受体并检测了受体蛋白的组织定位。结果表明，尿苷受体不仅在大脑中起作用，而且在周围组织中也起作用。分析了哌他嗪给药后大鼠脑内转运、受体结合及镇痛作用的药代动力学和药效学行为。少

The purpose of this research project is to clarify the organ specific transports of drugs from the view points of organ, cell, molecular and gene levels and to develop novel method for regulation of pharmacokinetics and pharmacodynamics of drugs. The following results were obtained by two years term of this research project consisted of 14 investigators :1.Several evidences were obtained for molecular and biological characteristics of transporters involved in the buccal and intestinal absorption and secretion, renal secretion and reabsorption, hepatic uptake and biliary secretion and in the brain influx and efflux transports. Cloning of transporters of PepT1, PepT2, MCT1, cMOAT,OAT-K1 and OCT2, their transport functions and tissue distribution were clarified. It was also clarified that P-glycoprotein functions as the transport barrier for lipophilic xenobiotics in the intestine and at the blood-brain barrier (BBB). Peptides were confirmed to be taken up by adsorptive-mediated endocytos … More is at the BBB to be delivered into the brain. 2.Improvement of absorption for drugs was achieved by glycosylation, endocytosis across Peyer's patches, iontophoretic method and by absorption enhancers to open tight junction. 3.Uptake of fractionated heparin by hepatocytes and Kupffer cells was clarified to be regulated by the scavenger receptor-mediated and plasma proteins-mediated mechanisms. Liver-specific delivery of drugs, proteins and gene was achieved by using galactosylated technology. Reactive oxygen species, such as superoxide and nitric oxide (NO), were clarified to play critical roles in the pathogenesis of various diseases. To overcome the oxidative stress, synthesized site-directed SOD derivatives were succeeded to deliver the targeting cells. An attractive approach for the antibody-based therapy of solid tumors was proposed and evaluated successfully by use of "vascular targeting" antibody to recognize tumor endothelial cells. 4.Using alpha 1-adrenoreceptor as a model, cloning of the receptors and detection of the tissue localization of the receptor protein were succeeded. It was indicated that uridine receptor plays some role not only in brain but also in peripheral tissues. Pharmacokinetic and pharmacodynamic behaviors for the transport in the brain, receptor binding and analgesic action were analyzed after peptazocine administration in rats. Less