高原低氧环境中药物转运体的表达和功能及其对药物吸收的影响

The pharmacokinetics of drugs and the activity and expression of drug metabolism enzymes were changed in special environment of high altitude hypoxia. Drug transporter is one of the main factors that affect the metabolism of drugs, so it is necessary to further study the expression and function of drug transporters and their effects on drug absorption under high altitude hypoxia environment.. The project will make use of special geographic environment of Qinghai-Tibet plateau, and regard PEPT1、OATP2B1、MDR1、MRP2 and BCRP as research objects. The study include: ① To analyse the change of drug transporters in acute and chronic hypoxia of environment high altitude, the protein and mRNA expression of five drug transporters will be determined by Real-time PCR and Western Blot in rat’s liver and small intestine of plain control, acute hypoxia and chronic hypoxia group, respectively. ② To evaluate the effect of drug transporters on the absorption of drugs in high altitude hypoxia environment, the absorption of specific substrates of five transporters was measured in rats intestine by single pass intestinal perfusion method. ③ To study the effect of hypoxia on the expression of protein and mRNA of five transporters in Caco-2 cells. ④ Caco-2 cell monolayer model was adopted to further study the effect of hypoxia on the function of drug transporters and drug absorption and transport.. The project will provide the guidance to explain drug’s metabolism in special environment of high altitude hypoxia, and give valuable references to clinical reasonable medication in plateau areas.

在高原低氧特殊环境中，药物的体内代谢发生显著改变。药物转运体是影响药物代谢的主要因素之一，高原低氧环境中药物转运体的表达和功能是否发生变化并进一步影响药物的吸收值得进一步去探讨。项目利用青藏高原独特的地理条件，以药物转运体PEPT1、OATP2B1、MDR1、MRP2和BCRP为研究对象，①采用定量PCR和Western blot分别测定平原、急性和慢性缺氧大鼠肝脏和肠转运体的蛋白和mRNA表达，分析高原急、慢性低氧环境中药物转运体的变化；②采用在体肠灌流法，分别测定5种转运体的底物在肠道的吸收情况，评价高原低氧环境中转运体的功能及对药物吸收的影响。③在Caco-2细胞中，验证低氧对转运体蛋白和mRNA表达的影响。④采用Caco-2单细胞层模型，进一步验证低氧对转运体功能及对药物吸收转运的影响。期望能为合理解释高原低氧环境中的药物代谢起一定指导作用，并对高原地区合理用药提供参考依据。

在高原低氧特殊环境中，药物的体内代谢发生显著改变。药物转运体是影响药物代谢的主要因素之一，高原低氧环境中药物转运体的表达和功能是否发生变化并进一步影响药物的吸收值得进一步去探讨。. 项目利用青藏高原独特的地理条件，以药物转运体PEPT1、OATP2B1、MDR1、MRP2和BCRP为研究对象，①采用定量PCR和Western blot分别测定平原、急性和慢性缺氧大鼠肝脏转运体的蛋白和mRNA表达，分析高原急、慢性低氧环境中药物转运体的变化；②采用在体肠灌流法，分别测定5种转运体的底物在肠道的吸收情况，评价高原低氧环境中转运体的功能及对药物吸收的影响。③在Caco-2细胞中，验证低氧对转运体蛋白和mRNA表达的影响。④采用Caco-2单细胞层模型，进一步验证低氧对转运体功能及对药物吸收的影响。. 研究发现，在高原低氧特殊环境中，大鼠药物转运体的表达和功能发生一定变化。高原环境中，大鼠MDR1的蛋白表达显著降低，PEPT1和BCRP的蛋白表达显著升高，OATP2B1的蛋白表达无明显变化；急性中海拔高原缺氧降低MRP2的蛋白表达，慢性高海拔高原缺氧升高MRP2的蛋白表达。高原环境中，大鼠MRP2和BCRP的mRNA表达显著升高，OATP2B1的mRNA表达无明显变化；不同海拔高度和缺氧时间对MDR1和PEPT1的mRNA表达影响不同。高原环境中，MDR1、OATP2B1、PEPT1的活性显著升高，BCRP的活性显著降低，急性中海拔缺氧组MRP2的活性显著降低，慢性高海拔缺氧组显著升高。低氧条件下，Caco-2细胞中MDR1、BCRP、PEPT1、OATP2B1的蛋白表达显著升高，MRP2的蛋白表达显著降低；MDR1、BCRP、PEPT1的mRNA表达显著升高，OATP2B1的mRNA表达显著降低，MRP2无明显变化；MDR1、BCRP、PEPT1、OATP2B1的活性显著升高，MRP2的活性显著降低。高原低氧环境下药物转运体功能发生变化，MDR1、MRP2、BCRP、PEPT1、OATP2B1底物药物的吸收受到影响，罗丹明123、长春新碱、乌苯美司、格列本脲的吸收均加快，哌唑嗪的吸收减慢。. 项目为合理解释高原低氧环境中的药物代谢起一定指导作用，并对高原地区合理用药提供理论依据。