Berger S P, Hünger M, Yard B A, Schnuelle P, Van Der Woude F J
Departments of Nephrology and Endocrinology, Vth Medical Clinic, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
Kidney Int. 2000 Dec;58(6):2314-9. doi: 10.1046/j.1523-1755.2000.00415.x.
In a retrospective study of the kidney transplantations performed at our institution, we found that the administration of dopamine (DA) to the organ donors resulted in a significant improvement of long-term organ survival of the retrieved kidneys. To study the mechanisms underlying the organ protection associated with the administration of DA prior to transplantation, we questioned whether DA induces the antioxidative enzyme heme oxygenase-1 (HO-1) in cultured endothelial cells.
Human umbilical vein endothelial cells (HUVECs) in culture were incubated with varying concentrations of DA for different time periods. Cells were subsequently assessed for the expression of HO-1 by Western blot and semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).
The presence of DA resulted in a dose- and time-dependent up-regulation of HO-1 both on RNA and protein level, whereas HO-1 was barely detectable under basal conditions. RT-PCR indicated the increased presence of HO-1 messenger RNA after 2 hours of incubation with DA, which peaked after 24 hours. The induction of HO-1 antigen was detectable after eight hours, as visualized by Western blot analysis. The addition of the antioxidant agents ascorbic acid and N-acetyl-cysteine both lead to dose-dependent inhibition of DA-mediated HO-1 induction. DA-mediated up-regulation of HO-1 was not influenced by the addition of either the D2-receptor antagonist haloperidol or the D1-receptor antagonist SCH 23390.
We conclude that DA induces the expression of the protective enzyme HO-1 in cultured endothelial cells by an oxidative mechanism. These findings may explain the beneficial effect of DA administration to kidney donors and indicate the potential role of DA in organ preconditioning.
在对我们机构进行的肾移植手术的回顾性研究中，我们发现给器官供体使用多巴胺（DA）可显著提高获取肾脏的长期器官存活率。为了研究移植前使用DA相关的器官保护潜在机制，我们探讨了DA是否能在培养的内皮细胞中诱导抗氧化酶血红素加氧酶-1（HO-1）。
将培养的人脐静脉内皮细胞（HUVECs）与不同浓度的DA孵育不同时间段。随后通过蛋白质印迹法和半定量逆转录-聚合酶链反应（RT-PCR）评估细胞中HO-1的表达。
DA的存在导致HO-1在RNA和蛋白质水平上呈剂量和时间依赖性上调，而在基础条件下几乎检测不到HO-1。RT-PCR表明与DA孵育2小时后HO-1信使核糖核酸的存在增加，在24小时后达到峰值。蛋白质印迹分析显示，8小时后可检测到HO-1抗原的诱导。添加抗氧化剂抗坏血酸和N-乙酰半胱氨酸均导致DA介导的HO-1诱导呈剂量依赖性抑制。DA介导的HO-1上调不受D2受体拮抗剂氟哌啶醇或D1受体拮抗剂SCH 23390添加的影响。
我们得出结论，DA通过氧化机制在培养的内皮细胞中诱导保护性酶HO-1的表达。这些发现可能解释了给肾供体使用DA的有益作用，并表明DA在器官预处理中的潜在作用。
