Schmitz Volker, Klawitter Jost, Bendrick-Peart Jamie, Schoening Wenzel, Puhl Gero, Haschke Manuel, Klawitter Jelena, Consoer Jeff, Rivard Christopher J, Chan Laurence, Tran Zung V, Leibfritz Dieter, Christians Uwe
Department of General, Visceral and Transplantation Surgery, Charité, Berlin, Germany.
Nephron Exp Nephrol. 2009;111(4):e80-91. doi: 10.1159/000209208. Epub 2009 Mar 17.
Cyclosporine and/or sirolimus impair recovery of renal transplants. This study examines the changes in urine metabolite profiles as surrogate markers of renal cell metabolism and function after cyclosporine and/or sirolimus treatment employing a rat kidney transplantation model.
Using inbred Lewis rats, kidneys were transplanted into bilaterally nephrectomized recipients followed by treatment with either CsA (cyclosporine) 10, Rapa (sirolimus) 1, CsA10/Rapa1 or CsA25/Rapa1 mg/kg/day for 7 days. On day 7, urine was analyzed by (1)H-NMR spectroscopy. Blood and kidney tissue drug concentrations, tissue high-energy compounds (including ATP, ADP) and oxidative stress markers (15-F(2t)-isoprostanes) in urine were measured by HPLC mass spectrometry.
Changes in urine metabolites followed the order Rapa1 < CsA10 < CsA10/Rapa1 < CsA25/Rapa1. Compared with controls, CsA25/Rapa1 showed the greatest changes (creatinine -36%, succinate -57%, citrate -89%, alpha-ketoglutarate -75%, creatine +498%, trimethylamine +210% and taurine +370%). 15-F(2t)-isoprostane concentrations in urine increased in the combined immunosuppressant-treated animals ([CsA25/Rapa1]: 795 +/- 222, [CsA10/Rapa1]: 475 +/- 233 pg/mg/creatinine) as compared with controls (165 +/- 78 pg/mg creatinine). Rapa concentration in blood and tissues increased in the combined treatment (blood: 31 +/- 8 ng/ml, tissue: 1.3 +/- 0.4 ng/mg) as compared with monotherapy (blood: 14 +/- 8 ng/ml, tissue: 0.35 +/- 0.15 ng/mg). Drug blood concentrations correlated with isoprostane urine concentrations, which correlated negatively with citrate, alpha-ketoglutarate and creatinine concentrations in urine. Only CsA25/Rapa1 significantly reduced high-energy metabolite concentrations in transplant kidney tissue (ATP -55%, ADP -24%).
Immunosuppressant drugs induce changes in urine metabolite patterns, suggesting that immunosuppressant-induced oxidative stress is an early event in the development of nephrotoxicity. Urine 15-F(2t)-isoprostane concentrations and metabolite profiles may be sensitive markers of immunosuppressant-induced nephrotoxicity.
环孢素和/或西罗莫司会损害肾移植的恢复。本研究采用大鼠肾移植模型，检测环孢素和/或西罗莫司治疗后尿液代谢物谱的变化，以此作为肾细胞代谢和功能的替代标志物。
使用近交系Lewis大鼠，将肾脏移植到双侧肾切除的受体中，随后分别用10mg/kg/天的环孢素（CsA）、1mg/kg/天的西罗莫司（Rapa）、10mg/kg/天的CsA + 1mg/kg/天的Rapa或25mg/kg/天的CsA + 1mg/kg/天的Rapa进行治疗，持续7天。在第7天，通过氢核磁共振波谱法分析尿液。采用高效液相色谱 - 质谱法测定血液和肾脏组织中的药物浓度、组织高能化合物（包括三磷酸腺苷（ATP）、二磷酸腺苷（ADP））以及尿液中的氧化应激标志物（15 - F(2t)-异前列腺素）。
尿液代谢物的变化顺序为Rapa1 < CsA10 < CsA10/Rapa1 < CsA25/Rapa1。与对照组相比，CsA25/Rapa1组的变化最大（肌酐 - 36%，琥珀酸 - 57%，柠檬酸 - 89%，α - 酮戊二酸 - 75%，肌酸 + 498%，三甲胺 + 210%，牛磺酸 + 370%）。联合免疫抑制剂治疗的动物尿液中15 - F(2t)-异前列腺素浓度升高（[CsA25/Rapa1]：795 ± 222，[CsA10/Rapa1]：475 ± 233 pg/mg/肌酐），而对照组为（165 ± 78 pg/mg肌酐）。联合治疗组血液和组织中的Rapa浓度升高（血液：31 ± 8 ng/ml，组织：1.3 ± 0.4 ng/mg），而单一疗法组为（血液：14 ± 8 ng/ml，组织：0.35 ± 0.15 ng/mg）。药物血液浓度与异前列腺素尿液浓度相关，而异前列腺素尿液浓度与尿液中的柠檬酸、α - 酮戊二酸和肌酐浓度呈负相关。只有CsA25/Rapa1显著降低了移植肾组织中的高能代谢物浓度（ATP - 55%，ADP - 24%）。
免疫抑制药物会引起尿液代谢物模式的变化，表明免疫抑制剂诱导的氧化应激是肾毒性发展过程中的早期事件。尿液15 - F(2t)-异前列腺素浓度和代谢物谱可能是免疫抑制剂诱导肾毒性的敏感标志物。
