Pharmacokinetics of 5 (and 6)-carboxy-2′,7′-dichlorofluorescein and its diacetate promoiety in the liver
Pharmacokinetics of 5 (and 6)-carboxy-2′,7′-dichlorofluorescein and its diacetate promoiety in the liver
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DOI：
10.1124/jpet.102.044107
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发表时间：
2003-02-01
影响因子：
3.5
通讯作者：
Brouwer, KLR
中科院分区：
文献类型：
--
作者：
Zamek-Gliszczynski, MJ;Xiong, H;Brouwer, KLR
研究了5（和6）-羧基-2′，7′-二氯荧光素（CDF）及其双乙酸促进物（CDFDA）在离体灌注大鼠肝脏中的肝脏分布。将Wistar野生型和多药耐药相关蛋白（Mrp）2缺陷（TR-）大鼠的肝脏灌注CDF，无论是否存在probenecid。在野生型肝脏中，Probenecid使胆汁中CDF的回收率降低了4倍（65 +/- 8% vs 15 +/- 2%剂量超过2小时）。在TR-大鼠的肝脏中，CDF没有排泄到胆汁中，而probenecid以浓度依赖的方式降低了灌注CDF的浓度，部分原因是抑制了Mrp3。用转染Mrp2或Mrp3的大鼠Sf9细胞的质膜囊泡来证实CDF是Mrp2和Mrp3的底物；probenecid以浓度依赖性的方式抑制Mrp2和Mrp3对CDF的转运。胶原三明治培养的大鼠肝细胞对CDF的摄取是温度依赖性和可饱和的（K-m = 22 +/- 10 muM; V-max = 97 +/- 9 pmol/min/mg protein）。三明治培养的大鼠肝细胞对CDF的摄取受到有机阴离子转运多肽（Oatps）底物溴磺胺吡啶（bromosulfophthalin）的显著损害，但不受特定的Oatp2或有机阴离子转运蛋白（Oat）底物的调节。CDFDA的摄取不饱和，温度依赖性，或被抑制剂损害。生物培养基中的碱性pH和酯酶介导CDFDA水解为CDF。CDFDA被动地扩散到肝细胞，在那里它被水解成CDF。相反，CDF似乎通过燕麦介导的转运进入大鼠肝细胞，并通过Mrp2进入胆汁，通过Mrp3进入窦血。
Hepatic disposition of 5 (and 6)-carboxy-2',7'-dichlorofluorescein (CDF) and its diacetate promoiety (CDFDA) was studied in isolated perfused rat livers. Livers from Wistar wild-type and multidrug resistance-associated protein (Mrp)2-deficient (TR-) rats were perfused with CDF in the presence or absence of probenecid. Probenecid decreased the recovery of CDF in bile similar to4-fold in wild-type livers (65 +/- 8% versus 15 +/- 2% of dose over 2 h). In livers from TR- rats, CDF was not excreted into bile and probenecid decreased perfusate CDF concentrations in a concentration-dependent manner, in part due to inhibition of Mrp3. Plasma membrane vesicles from rat Mrp2- or Mrp3-transfected Sf9 cells were used to confirm that CDF is a substrate for Mrp2 and Mrp3; probenecid inhibited the transport of CDF by Mrp2 and Mrp3 in a concentration-dependent manner. CDF uptake in collagen sandwich-cultured rat hepatocytes was temperature-dependent and saturable (K-m = 22 +/- 10 muM; V-max = 97 +/- 9 pmol/min/mg protein). Uptake of CDF in sandwich-cultured rat hepatocytes was impaired significantly by bromosulfophthalein, a substrate for organic anion-transporting polypeptides (Oatps), but was not modulated by specific Oatp2 or organic anion transporter (Oat) substrates. CDFDA uptake was not saturable, temperature-dependent, or impaired by inhibitors. The hydrolysis of CDFDA to CDF is mediated by basic pH and esterases in biological media. CDFDA passively diffuses into hepatocytes where it is hydrolyzed to CDF. In contrast, CDF appears to be taken up by Oatp-mediated transport into rat hepatocytes and effluxed via Mrp2 into bile and via Mrp3 into sinusoidal blood.