NOS2 and metabolic syndrome: After L-arginine treatment, the levels of NFκB-P65, DNP, and nitrotyrosine were meaningfully reduced in the MetS + L-arginine group and the MetS + OVX + L-arginine group compared to the MetS group and the MetS + OVX group, whereas the levels of all NOS, HIF-1α, and NRF2 were significantly strengthened.