Pilz Stefan, Meinitzer Andreas, Gaksch Martin, Grübler Martin, Verheyen Nicolas, Drechsler Christiane, Hartaigh Bríain Ó, Lang Florian, Alesutan Ioana, Voelkl Jakob, März Winfried, Tomaschitz Andreas
Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria,
Amino Acids. 2015 Sep;47(9):1703-13. doi: 10.1007/s00726-015-1993-2. Epub 2015 May 1.
Homoarginine (hArg) is an endogenous, nonproteinogenic amino acid which differs from arginine by an additional methylene (CH2) group in the backbone. In this brief narrative review, we summarize the current literature on hArg in the renal and cardiovascular systems. Epidemiological studies have identified low hArg levels as an independent risk marker for cardiovascular, cerebrovascular, and renal diseases as well as for mortality. The relatively low correlation of hArg with established cardiovascular risk factors underlines its great potential as an emerging biomarker to improve risk prediction because plasma hArg concentrations might reflect previously unrecognized pathophysiological processes. hArg may be involved in the pathogenesis of various diseases due to its effects on nitric oxide (NO) and energy metabolism. In view of its structural similarities with arginine, it has been proposed that hArg impacts on arginine metabolism and subsequently also on NO synthesis. The key enzyme for hArg synthesis, arginine:glycine amidinotransferase (AGAT), is involved in the synthesis of energy metabolites including guanidinoacetate, the precursor of creatine. Therefore, the involvement of hArg in energy metabolism could partially explain the close association between hArg and cardiovascular diseases such as heart failure. Whether hArg supplementation or modification of key enzymes of hArg metabolism such as AGAT activity is effective for the treatment of chronic diseases remains to be elucidated.
高瓜氨酸（hArg）是一种内源性的非蛋白质氨基酸，其主链上比精氨酸多一个亚甲基（CH2）基团。在这篇简短的叙述性综述中，我们总结了目前关于hArg在肾脏和心血管系统方面的文献。流行病学研究已将低hArg水平确定为心血管、脑血管和肾脏疾病以及死亡率的独立风险标志物。hArg与已确定的心血管风险因素的相关性相对较低，这突出了其作为一种新兴生物标志物改善风险预测的巨大潜力，因为血浆hArg浓度可能反映了以前未被认识的病理生理过程。由于hArg对一氧化氮（NO）和能量代谢的影响，它可能参与各种疾病的发病机制。鉴于其与精氨酸的结构相似性，有人提出hArg会影响精氨酸代谢，进而也影响NO的合成。hArg合成的关键酶，即精氨酸：甘氨酸脒基转移酶（AGAT），参与包括胍基乙酸（肌酸的前体）在内的能量代谢物的合成。因此，hArg参与能量代谢可以部分解释hArg与诸如心力衰竭等心血管疾病之间的密切关联。hArg补充或hArg代谢关键酶（如AGAT活性）的调节对慢性病治疗是否有效仍有待阐明。
