NO control: nitric oxide directly regulates substrate delivery to NOS. Focus on Nitric oxide can acutely modulate its biosynthesis through a negative feedback mechanism on L-arginine transport in cardiac myocytes'.

摘要

Although the amino acid arginine is commonly associated with nitric oxide (NO) production via NO synthase (NOS), it also participates in the synthesis of urea, creatine, creatinine, agmatine, polyamines, as well as overall protein synthesis. Furthermore, it also influences hormone release (insulin, pro-lactin, and others) and synthesis of pyrimidine bases. Thus, physiologically arginine participates in disposal of protein metabolic waste, muscle metabolism, vascular regulation, immune system function, neurotransmission, RNA synthesis, and hormone-mediated signaling (4). More importantly, although all cells require arginine, not all cells possess the metabolic capacity to produce it and thus must obtain arginine via the circulation. In cells that must acquire L-arginine exogenously, it seems logical that there would be regulatory mechanisms in place to moderate the rate of L-arginine uptake via cationic amino acid transporters (CATs). Surprisingly, there are few reports that address CATs as possible metabolic sites of regulation.