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Physiological/pathophysiological states with increased sympathetic nerve activity (SNA) are associated with oxidative stress. It is known that increased O2• - in specific brain regions results in increased efferent SNA. Recently we found that NE increased intracellular O2• - production (Dihydroethidium, DHE) and mRNA for NADPH oxidase (NOX-2) subunits in cultured PBMCs from humans suggesting elevated SNA may increase systemic O2• - production. Current experiments tested whether the rat is a good experimental model of humans to further study the interaction between sympathoexcitation and PBMC-derived O2• -. Primary PBMCs and splenocytes were isolated from male rats and incubated at 37°C for 36 hr with either vehicle (Veh), 50 pcg/ml, 50 ng/ml, or 50 µg/ml NE. Similar to human PBMCs, relative to Veh, NE increased intracellular O2• - production in rat PBMCs (50 µg/ml NE = 11± 5 fold; P< 0.05) and tended to increase mRNA for NOX-2 subunits (50 ng/ml NE: gp 91phox = 1.8 ± 0.4; p22phox = 1.6± 0.5). NE also incr...

Although heart failure (HF) patients exhibit elevated levels of ROS, the sources and mechanisms contributing to the increase in ROS remain unclear. Recent work has shown that peripheral blood mononuclear cells (PBMCs) are a major source of NADPH oxidase-derived superoxide (O2●-) production. Therefore, we measured systemic ROS, O2●-, and expression of NADPH oxidase and its potential activators, angiotensin II type 1 receptors (AT1R) and Rho Kinase (ROCK) 1, in PBMCs from 6 HF (ejection fraction 22±4%) and 6 age-matched healthy controls. Total ROS and O2●- levels were measured in blood using electron paramagnetic resonance spectroscopy. Protein expression of NADPH oxidase subunits (gp91phox, p22phox, p47phox and p67phox), AT1R and ROCK1 were assessed from PBMCs using western blot. Total ROS and O2●- levels were elevated in blood from HF patients compared to controls (P