Contribution of whole blood to the control of plasma asymmetrical dimethylarginine
Contribution of whole blood to the control of plasma asymmetrical dimethylarginine
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DOI：
10.1152/ajpheart.00066.2006
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发表时间：
2006-10-01
影响因子：
4.8
通讯作者：
D'Alecy, Louis G.
中科院分区：
文献类型：
--
作者：
Billecke, Scott S.;Kitzmiller, Laura A.;D'Alecy, Louis G.
内源性一氧化氮（NO）合酶（NOS）抑制剂不对称二甲基精氨酸（ADMA）在许多患者中升高，可能导致其疾病的发生和进展。虽然已经确定了一些机制途径，但组织特异性对ADMA控制的贡献仍不清楚。我们试图确定全血（WB）是否可以参与体外ADMA控制。将麻醉的雄性Sprague-Dawley大鼠放血，并将WB制剂在37 ℃下孵育5小时。ADMA和对称二甲基精氨酸采用高压液相色谱法进行分析。裂解红细胞（RBC）上清液的孵育产生了ADMA的显着减少，这是由4124 W，二甲基精氨酸二甲氨基水解酶，唯一的报告酶水解ADMA的合成抑制剂阻断。通过加入生理相关浓度的锌（即，20 μ M）。相反，当大鼠WB或WB上清液在37 ℃下孵育时，它释放出一定量的游离ADMA（1-2 μ M），其在体内可能具有病理学后果。添加精氨酸甲基转移酶抑制剂，这些孵育没有减少ADMA的释放，表明在这些孵育过程中活性蛋白质甲基化没有主导作用。这种ADMA释放显着减少，通过添加蛋白酶抑制剂，表明依赖于肽键水解。通过酸水解测定总ADMA（蛋白质结合加游离），发现WB中的ADMA为43.18 +/- 4.79 μ M，与RBC中的ADMA含量的95%相似。这些离体数据证明了血液通过调节游离ADMA来控制NO-NOS系统的潜力。
The endogenous nitric oxide (NO) synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is elevated in many patients and may contribute to the initiation and progression of their disease. While some mechanistic pathways have been identified, tissue-specific contributions to ADMA control remain unclear. We sought to determine if whole blood (WB) could participate in ADMA control ex vivo. Anesthetized male Sprague-Dawley rats underwent exsanguinations, and WB preparations were incubated at 37 degrees C for 5 h. ADMA and symmetrical dimethylarginine were analyzed by high-pressure liquid chromatography. Incubation of lysed red blood cell (RBC) supernatant yielded a significant decrease in ADMA that was blocked by 4124W, a synthetic inhibitor of dimethylarginine dimethylaminohydrolase, the only reported enzyme to hydrolyze ADMA. Hydrolysis of ADMA was diminished by addition of physiologically relevant concentrations of zinc (i.e., 20 mu M). Conversely, when rat WB or WB supernatant was incubated at 37 degrees C, it liberated quantities of free ADMA (1-2 mu M) that in vivo would likely have pathological consequences. Addition of arginine methyltransferase inhibitors to these incubations did not reduce ADMA release, indicating no dominant role for active protein methylation during these incubations. This ADMA liberation was significantly reduced by addition of protease inhibitors, indicating a dependence on peptide bond hydrolysis. Total ADMA (protein incorporated plus free) was determined by acid hydrolysis and found to be 43.18 +/- 4.79 mu M in WB with similar to 95% of this in RBCs. These ex vivo data demonstrate the potential of blood to control the NO-NOS system by modulating free ADMA.