Variations of Nitrate-reducing Activity in Oral Rothia mucilaginosa

18 INTRODUCTION Nitric oxide (NO) is a signaling molecule with the ability to affect various biological functions including vascular homeostasis, neurotransmission, gastric physiology, mitochondrial function, and, through its antibacterial effects, host defense. Several recent reports have shown that the prominent role of NO lies in its beneficial effects on blood pressure and vascular health . In human physiology, there are two major NO generation pathways; the first of these is the endogenous L-arginin–NO synthase (NOSs) pathway, in which NOS catalyzes L-arginin and molecular oxygen to Variations of Nitrate-reducing Activity in Oral Rothia mucilaginosa