OBJECTlVE To investigate the inhibition of Radix lsatidis and its major constituents indigo and indirubin on three principal subtypes of organic anion transporters ( OATs) , Oat1, Oat2 and Oat3 in vivo in mice. METHODS Granules of Radix lsatidis ( GRl) 0.615 and 2.46 g·kg-1 , decoction of Radix lsatidis ( DRl) 1.6 and 6.4 g·kg-1 , indigo 0.008 and 0.64 mg·kg-1 and indirubin 0.0192 and 1.536 mg·kg-1 were ig given to the NlH mice (60 mice per group), twice a day, for 5 d while four control groups were set up, including vehicle of water, 0.5%sodium carboxymethyl cellulose ( CMC) , positive control probe-necid (0.05 g·kg-1) and additives of sucrose plus dextrin (1.5 g·kg-1 each) groups. After the last dosing of the test samples, para-aminohippuric acid ( PAH) clearance test was conducted. All the mice were iv given PAH 0.03 g·kg-1 and 1, 2.5, 5, 7.5, 10 and 20 min later before 10 mice per group were euthanized to collect whole blood and the kidneys were quickly removed. Each right kidney was homoge-nized to analyze the PAH accumulations and each left kidney to extract total mRNA for analysis of Oat1, Oat2 and Oat3 gene expressions using quantitative real-time PCR. The concentrations of PAH in sera and in kidney homogenates were determined by the method of Kiguchi. Major pharmacokinetic parame-ters of PAH in sera were calculated by pharmacokinetic software ( DAS2.0) . PAH uptake test for kidney slices was performed on another group of NlH mice according to the method of Nakakariya. RESULTS There was no significant difference between water control group and 0.5%CMC group in all the examined items. Compared with the vehicle control groups ( water and 0. 5%CMC group ) , elimination half time ( t1/2β) of PAH in GRl 2.46 g·kg-1 ,indigo 0.64 mg·kg-1 and indirubin 1.536 mg·kg-1 groups was signifi-cantly prolonged (P<0.05), the total clearance (Cl) and volume of distribution (Vd) were obviously reduced ( P<0.01) and the area under the curve ( AUC0-20 min ) of PAH in all the tested groups was signifi-cantly increased ( P<0.01) . AUC0-20 min obtained from renal PAH accumulations within the checked time was significantly higher ( P<0.05, P<0.01) than in the vehicle control group. But there was in no signifi-cant difference between all the study groups in kidney-to-plasma AUC ratios. PAH uptake results by kidney slices were significantly lower ( P<0. 05, P<0. 01 ) than in vehicle control group in every two dosages of all the four samples tested. Compared with vehicle control group, the mRNA expressions of Oat1, Oat2 and Oat3 were obviously ( P<0.05, P<0.01) and abnormally regulated in the groups of GRl 2.46 g·kg-1, DRl 6.4 g·kg-1, indigo 0.64 mg·kg-1 and indirubin 1.536 mg·kg-1. CONCLUSlON The renal Oat1, Oat2 and Oat3 of mice are significantly inhibited by GRl, DRl, indigo and indirubin. The inhibitory function of Radix lsatidis probably stems from indigo and indirubin contained in it.%目的：探讨板蓝根颗粒剂( GRl)和饮片水煎剂( DRl)及其所含主要成分靛蓝和靛玉红对小鼠肾有机阴离子转运体( OAT)中3个主要亚型Oat1,Oat2和Oat3的影响。方法 NlH小鼠分别ig给予GRl 0.615和2.460 g·kg－1,DRl 1.6和6.4 g·kg－1(生药量),靛蓝0.008和0.640 mg·kg－1,靛玉红0.0192和1.5360 mg·kg－1,每组60只(雌雄对半),每天2次,连续5 d。同时设丙磺舒(0.05 g·kg－1)阳性对照组和两种溶媒〔纯水和0.5％羧甲纤维素钠( CMC-Na)水溶液〕对照组及糊精加蔗糖(各1.5 g·kg－1)添加剂组。最后1次给予供试物后实施对-氨基马尿酸( PAH, iv,0.03 g·kg－1)清除实验,即在iv PAH后1.0,2.5,5.0,7.5,10.0和20.0 min 时每组分别各取10只小鼠(雌雄对半),安乐处死收集全血制备血清,并迅速摘取双肾,右肾进行组织匀浆后测定PAH蓄积量,左肾组织用于提取总mRNA。每组另取10只小鼠(雌雄各半),同样给药处理,按Nakakariya法做肾切片进行摄取PAH实验。用Kiguchi法测定血清和肾组织匀浆液中PAH浓度。以药动学软件( DAS 2.0)计算血清及肾组织中PAH的主要药动学参数。以实时定量PCR法测定小鼠肾组织Oat1,Oat2及Oat3 mRNA表达。结果与纯水对照组比较,0.5％CMC-Na对照组各项检测指标均无显著差异。与两种溶媒对照组相比, GRl 2.460 g·kg－1,靛蓝0.640 mg·kg－1和靛玉红1.5360 mg·kg－1组消除半衰期( t1/2β)显著延长( P<0.05)；各供试物组分布容积( Vd )和清除率( Cl)均显著减少(P<0.01),曲线下面积(AUC0→20 min)均显著增加(P<0.01)；由采血时间段内各组肾组织中的PAH蓄积量所求得的AUC0→20 min显著大于同期对照组( P<0.05,P<0.01),且肾AUC0→20 min与血液AUC0→20 min的比值在各组间无显著差异。各剂量供试物均可使肾切片摄取PAH的量显著少于对照组( P<0.05,P<0.01)。与纯水/CMC对照组相比,GRl 2.460 g·kg－1,DRl 6.4 g·kg－1,靛蓝0.640 mg·kg－1,靛玉红1.5360 mg·kg－1组小鼠肾组织Oat1,Oat2及Oat3 mRNA表达除靛玉红组Oat2 mRNA( P<0.05)、GRl组Oat3 mRNA( P<0.01)表达水平被显著上调外,其余均被显著下调( P<0.05,P<0.01)。结论 GRl、DRl、靛蓝、靛玉红在所用剂量下对小鼠肾组织Oat1,Oat2及Oat3均有明显抑制作用,GRl和DRl的这种抑制作用可能主要来自其所含的靛蓝和靛玉红成分。
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