L-ornithine ((S)-2,5-Diaminopentanoic acid) is a naturally occurring non-protein amino acid that plays an important role in the body's urea cycle. L-ornithine is not directly involved in the construction of proteins and is mainly used in the urea cycle to remove excess nitrogen from the body. L-ornithine has renal protection [1-3].
L-ornithine(300μM; 24h) activates Ca2+ signaling to exert its protective function on human proximal tubular cells[4]. L-ornithine (1–40mM) decreased cell impedance and elevated the BBB model permeability in primary rat brain endothelial cells[5].
L-ornithine(0.1875, 0.75 or 3mmol/10ml/kg; p.o) administered orally elevates brain L-ornithine levels and has an anxiolytic-like effect in mice[6]. Systemic L-ornithine(500mg/kg; p.o) supplementation specifically increases ovarian putrescine levels during ovulation in mice[7].
References:
[1]. Demura S, Morishita K, et,al. Effect of L-ornithine hydrochloride ingestion on intermittent maximal anaerobic cycle ergometer performance and fatigue recovery after exercise. Eur J Appl Physiol. 2011 Nov;111(11):2837-43. doi: 10.1007/s00421-011-1896-1. Epub 2011 Mar 23. PMID: 21431425.
[2]. Wu G, Morris SM Jr. Arginine metabolism: nitric oxide and beyond. Biochem J. 1998 Nov 15;336 ( Pt 1)(Pt 1):1-17. doi: 10.1042/bj3360001. PMID: 9806879; PMCID: PMC1219836.
[3]. Morris SM Jr. Regulation of enzymes of the urea cycle and arginine metabolism. Annu Rev Nutr. 2002;22:87-105. doi: 10.1146/annurev.nutr.22.110801.140547. Epub 2002 Jan 4. PMID: 12055339.
[4]. Shin S, Gombedza FC, Bandyopadhyay BC. l-ornithine activates Ca2+ signaling to exert its protective function on human proximal tubular cells. Cell Signal. 2020 Mar;67:109484. doi: 10.1016/j.cellsig.2019.109484. Epub 2019 Nov 23. PMID: 31770578; PMCID: PMC7302702.
[5].Walter FR, Harazin A, et,al. Blood-brain barrier dysfunction in L-ornithine induced acute pancreatitis in rats and the direct effect of L-ornithine on cultured brain endothelial cells. Fluids Barriers CNS. 2022 Feb 17;19(1):16. doi: 10.1186/s12987-022-00308-0. PMID: 35177109; PMCID: PMC8851707.
[6]. Kurata K, Nagasawa M, et,al. Orally administered L-ornithine elevates brain L-ornithine levels and has an anxiolytic-like effect in mice. Nutr Neurosci. 2011 Nov;14(6):243-8. doi: 10.1179/1476830511Y.0000000018. PMID: 22053755.
[7]. Lavergne CLJ, Tao Y,et,al. Systemic L-ornithine supplementation specifically increases ovarian putrescine levels during ovulation in mice†. Biol Reprod. 2022 Apr 26;106(4):792-801. doi: 10.1093/biolre/ioab233. PMID: 34935905.
L-ornithine ((S)-2,5-Diaminopentanoic acid)是一种天然存在的非蛋白质氨基酸，在人体的尿素循环中发挥重要作用。L-ornithine不直接参与蛋白质的合成，主要用于尿素循环中去除体内多余的氮。L-ornithine具有肾脏保护作用[1-3]。
L-ornithine(300μM; 24h)激活Ca2+信号，对人近端小管细胞发挥保护作用[4]。L-ornithine (1–40mM)降低了原代大鼠脑内皮细胞的细胞阻抗，提高了血脑屏障模型的通透性[5]。
L-ornithine (0.1875, 0.75 or 3mmol/10ml/kg; p.o)可提高小鼠脑内左旋鸟氨酸水平，并具有抗焦虑样作用[6]。全身补充L-ornithine (500 mg/kg; p.o)可提高小鼠排卵期卵巢腐胺水平[7]。