Fig. 2

Proposed mechanisms of effects of nitrate/nitrite on glucose homeostasis and insulin signaling. Nitrate/nitrite increase insulin secretion by increasing pancreatic islet blood flow (1) and activation of guanylyl cyclase and cGMP pathway (2). Nitrate/nitrite induce NO production and improve insulin resistance and glucose uptake by increasing gene expression of GLUT4 (3). Nitrate/nitrite increase nitrosation and insulin-independent translocation of GLUT4 and increase glucose uptake by skeletal muscle and adipose tissue (4). Nitrate/nitrite also inhibits production of reactive oxygen species (ROS) in adipoceytes and dephosphorylation activity of protein-tyrosine phosphatase 1B and then facilitate phosphorylation of insulin receptor substrate and subsequently GLUT4 translocation and glucose uptake (5). ROS; Reactive oxygen species, IRS; Insulin receptor substrate, PI3K; Phosphatydal inositol 3 kinase, PKB; Protein kinase B, GLUT4; Glucose transporter 4, NO; Nitric oxide