Erythrocyte nitric oxide availability and oxidative stress following exercise

Abstract

Growing evidence has shown that acute exercise impairs erythrocyte membrane structure and function as a consequence of increased physical and chemical stress. Erythrocyte-synthesized nitric oxide (NO) is known to modulate membrane fluidity, and its bioavailability depends on the balance between its production and scavenging by reactive oxygen species. Here, we investigated whether a maximal exercise test could affect erythrocyte NO bioavailability and oxidative stress. Twelve men (26±4 years old, V̇O2peak 44.1±4.3 mL·kg-1·min-1) performed a treadmill maximal cardiopulmonary exercise test. Blood was collected at rest and immediately after exercise for erythrocytes isolation. Maximal exercise caused an increase in erythrocytes count, haemoglobin and haematocrit levels. There was no change in L-arginine influx into erythrocytes after exercise. Yet, nitric oxide synthase activity, and thus, NO production, was increased after maximal test, as well cyclic GMP levels. In relation to biomarkers of oxidative stress, maximal test resulted in increased levels of lipid peroxidation, and diminished superoxide dismutase activity. Neither glutathione peroxidase nor catalase activity was affected by maximal test. Our findings demonstrate that the increased erythrocyte membrane rigidity caused by an acute bout of exercise may be caused, in part, by an increased lipid oxidative damage caused by ROS produced exogenously.

Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice

“…The antioxidant SOD was significantly decreased by CeO 2 NPs, whereas that of GSH was increased. The decrease of SOD activity indicates that it has been consumed as a result of oxidative stress [22, 45, 46]. The increase of GSH in the lung suggests that the development of oxidative stress is followed by an adaptive reaction that balances the potentially damaging activity of ROS by antioxidant defence mechanisms [28, 47].…”

Increased vascular function and superoxide dismutase activity in physically active vs inactive adults living with HIV

“…Protein carbonylation, lipid peroxidation, antioxidant enzymes activity, and nitric oxide bioavailability were assessed as described elsewhere . Briefly, oxidative damage to proteins was measured by quantifying carbonyl groups based on reaction with dinitrophenylhydrazine (Sigma™, St. Louis, MO, USA).…”

“…Protein carbonylation, lipid peroxidation, antioxidant enzymes activity, and nitric oxide bioavailability were assessed as described elsewhere. 28,29 Briefly, oxidative damage to proteins was measured by quantifying carbonyl groups based on reaction with dinitrophenylhydrazine (Sigma™, St. Louis, MO, USA). Carbonyl contents were determined from absorbance at 370 nm and total protein concentration was assayed using BCA assay kit (Bioagency™, Sao Paulo, SP, Brazil).…”

The impact of exercise frequency upon microvascular endothelium function and oxidative stress among patients with coronary artery disease

“…Nitric oxide bioavailability, lipid peroxidation and catalase activity were assessed as previously described (Huguenin et al, 2015;Medeiros-Lima et al, 2017). Briefly, the evaluation of total plasma NOx (NO2 + NO3) concentrations was performed by a colorimetric assay (Cayman Inc., USA) with a sensitivity of 2Á5 lM and a 2Á7% intra-assay coefficient of variation.…”