Biology of the Nutraceutical L-Citrulline

L-瓜氨酸（LC）是一种α-氨基酸，由L-鸟苷酸和氨甲酰基磷酸在尿素循环中通过鸟苷酸氨甲酰基转移酶合成，同时它也是一氧化氮（NO）合酶（NOS）反应的副产物，该反应将L-瓜氨酸转化为L-精氨酸和NO。有趣的是，LC可以作为膳食补充剂在柜台购买。在人类中的研究已经表明，LC可以作为一个性能增强剂，然而，LC的生物学作用，LC可以提高性能的机制已经相对不足的研究。

L-citrulline (LC) is an a-amino acid synthesized from L-ornithine and carbamoyl phosphate in the Urea Cycle via ornithine carbamoyltransferase, while it also serves as a by-product of the nitric oxide (NO) synthase (NOS) reaction, which converts L-arginine into LC and NO. Of interest, LC can be purchased over the counter as a dietary supplement. Studies in humans have shown that LC may act as a performance enhancer, however, the biological actions of LC, and the mechanisms by which LC may enhance performance have been relatively understudied.