Sziráki István, Erdo Franciska, Beéry Erzsébet, Molnár Petra Magdolna, Fazakas Csilla, Wilhelm Imola, Makai Ildikó, Kis Emese, Herédi-Szabó Krisztina, Abonyi Tibor, Krizbai István, Tóth Gábor K, Krajcsi Péter
Laboratory of Microdialysis, Solvo Biotechnology, Berlini u. 47-49, Budapest, Hungary.
J Biomol Screen. 2011 Sep;16(8):886-94. doi: 10.1177/1087057111414896. Epub 2011 Aug 10.
This study provides evidence that quinidine can be used as a probe substrate for ABCB1 in multiple experimental systems both in vitro and in vivo relevant to the blood-brain barrier (BBB). The combination of quinidine and PSC-833 (valspodar) is an effective tool to assess investigational drugs for interactions on ABCB1. Effects of quinidine and substrate-inhibitor interactions were tested in a membrane assay and in monolayer assays. The authors compared quinidine and digoxin as ABCB1 probes in the in vitro assays and found that quinidine was more potent and at least as specific as digoxin in ATPase and monolayer efflux assays employing MDCKII-MDR1 and the rat brain microcapillary endothelial cell system. Brain exposure to quinidine was tested in dual-/triple-probe microdialysis experiments in rats by assessing levels of quinidine in blood and brain. Comparing quinidine levels in dialysate samples from valspodar-treated and control animals, it is evident that systemic/local administration of the inhibitor diminishes the pumping function of ABCB1 at the BBB, resulting in an increased brain penetration of quinidine. In sum, quinidine is a good probe to study ABCB1 function at the BBB. Moreover, quinidine/PSC-833 is an ABCB1-specific substrate/inhibitor combination applicable to many assay systems both in vitro and in vivo.
本研究提供了证据表明，在与血脑屏障（BBB）相关的多个体外和体内实验系统中，奎尼丁可作为ABCB1的探针底物。奎尼丁与PSC-833（伐司朴达）的组合是评估研究药物与ABCB1相互作用的有效工具。在膜试验和单层试验中测试了奎尼丁和底物-抑制剂相互作用的影响。作者在体外试验中比较了奎尼丁和地高辛作为ABCB1探针，发现在使用MDCKII-MDR1和大鼠脑微血管内皮细胞系统的ATP酶和单层外排试验中，奎尼丁比地高辛更有效且至少具有相同的特异性。通过评估血液和脑中奎尼丁的水平，在大鼠的双/三探针微透析实验中测试了脑对奎尼丁的暴露情况。比较来自伐司朴达处理动物和对照动物的透析液样本中的奎尼丁水平，很明显，抑制剂的全身/局部给药会降低BBB处ABCB1的泵功能，导致奎尼丁的脑渗透增加。总之，奎尼丁是研究BBB处ABCB1功能的良好探针。此外，奎尼丁/PSC-833是一种ABCB1特异性底物/抑制剂组合，适用于许多体外和体内试验系统。
