Scialis Renato J, Csanaky Iván L, Goedken Michael J, Manautou José E
University of Connecticut, School of Pharmacy, Department of Pharmaceutical Sciences, Storrs, Connecticut (R.J.S., J.E.M.); University of Kansas Medical Center, Department of Internal Medicine, Kansas City, Kansas (I.L.C.); and Office of Translational Science, Rutgers University, Piscataway, New Jersey (M.J.G.).
University of Connecticut, School of Pharmacy, Department of Pharmaceutical Sciences, Storrs, Connecticut (R.J.S., J.E.M.); University of Kansas Medical Center, Department of Internal Medicine, Kansas City, Kansas (I.L.C.); and Office of Translational Science, Rutgers University, Piscataway, New Jersey (M.J.G.)
Drug Metab Dispos. 2015 Jul;43(7):944-50. doi: 10.1124/dmd.114.061705. Epub 2015 Apr 20.
Diclofenac (DCF) is a nonsteroidal anti-inflammatory drug commonly prescribed to reduce pain in acute and chronic inflammatory diseases. One of the main DCF metabolites is a reactive diclofenac acyl glucuronide (DCF-AG) that covalently binds to biologic targets and may contribute to adverse drug reactions arising from DCF use. Cellular efflux of DCF-AG is partially mediated by multidrug resistance-associated proteins (Mrp). The importance of Mrp2 during DCF-induced toxicity has been established, yet the role of Mrp3 remains largely unexplored. In the present work, Mrp3-null (KO) mice were used to study the toxicokinetics and toxicodynamics of DCF and its metabolites. DCF-AG plasma concentrations were 90% lower in KO mice than in wild-type (WT) mice, indicating that Mrp3 mediates DCF-AG basolateral efflux. In contrast, there were no differences in DCF-AG biliary excretion between WT and KO, suggesting that only DCF-AG basolateral efflux is compromised by Mrp3 deletion. Susceptibility to toxicity was also evaluated after a single high DCF dose. No signs of injury were detected in livers and kidneys; however, ulcers were found in the small intestines. Furthermore, the observed intestinal injuries were consistently more severe in KO compared with WT. DCF covalent adducts were observed in liver and small intestines; however, staining intensity did not correlate with the severity of injuries, implying that tissues respond differently to covalent modification. Overall, the data provide strong evidence that (1) in vivo Mrp3 plays an important role in DCF-AG disposition and (2) compromised Mrp3 function can enhance injury in the gastrointestinal tract after DCF treatment.
双氯芬酸（DCF）是一种非甾体抗炎药，常用于减轻急慢性炎症性疾病的疼痛。DCF的主要代谢产物之一是具有反应活性的双氯芬酸酰基葡萄糖醛酸（DCF-AG），它能与生物靶点共价结合，并可能导致DCF使用引起的药物不良反应。DCF-AG的细胞外排部分由多药耐药相关蛋白（Mrp）介导。Mrp2在DCF诱导的毒性中的重要性已得到证实，但Mrp3的作用在很大程度上仍未得到探索。在本研究中，使用Mrp3基因敲除（KO）小鼠来研究DCF及其代谢产物的毒代动力学和毒效动力学。KO小鼠的DCF-AG血浆浓度比野生型（WT）小鼠低90%，表明Mrp3介导DCF-AG的基底外侧外排。相比之下，WT和KO小鼠之间的DCF-AG胆汁排泄没有差异，这表明只有DCF-AG的基底外侧外排在Mrp3缺失时受到影响。在单次给予高剂量DCF后，还评估了对毒性的易感性。在肝脏和肾脏中未检测到损伤迹象；然而，在小肠中发现了溃疡。此外，与WT相比，KO小鼠中观察到的肠道损伤始终更严重。在肝脏和小肠中观察到了DCF共价加合物；然而，染色强度与损伤严重程度不相关，这意味着组织对共价修饰的反应不同。总体而言，这些数据提供了有力证据，即（1）在体内Mrp3在DCF-AG处置中起重要作用，以及（2）Mrp3功能受损可增强DCF治疗后胃肠道的损伤。
