Effects of acute and chronic endurance exercise on intracellular nitric oxide and superoxide in circulating CD34⁺ and CD34⁻ cells

J Appl Physiol (1985). 2011 Sep;111(3):929-37. doi: 10.1152/japplphysiol.00541.2011. Epub 2011 Jun 23.


We investigated the influence of acute and chronic endurance exercise on levels of intracellular nitric oxide (NO), superoxide (O₂·⁻), and expression of genes regulating the balance between these free radicals in CD34⁺ and CD34⁻ peripheral blood mononuclear cells (PBMCs; isolated by immunomagnetic cell separation). Blood samples were obtained from age- and body mass index (BMI)-matched endurance-trained (n = 10) and sedentary (n = 10) men before and after 30 min of exercise at 75% maximal oxygen uptake (·VO(₂max)). Baseline levels of intracellular NO (measured by DAF-FM diacetate) and O₂·⁻ (measured by dihydroethidium) were 26% (P < 0.05) and 10% (P < 0.05) higher, respectively, in CD34⁺ PBMCs from the sedentary group compared with the endurance-trained group. CD34⁺ PBMCs from the sedentary group at baseline had twofold greater inducible nitric oxide synthase (iNOS) mRNA and 50% lower endothelial NOS (eNOS) mRNA levels compared with the trained group (P < 0.05). The baseline group difference in O₂·⁻ was eliminated by acute exercise. Experiments with apocynin indicated that the training-related difference in O₂·⁻ levels was explained by increased NADPH oxidase activity in the sedentary state. mRNA levels of additional angiogenic and antioxidant genes were consistent with a more angiogenic profile in CD34⁺ cells of trained subjects. CD34⁻ PBMCs, examined for exploratory purposes, also displayed a more angiogenic mRNA profile in trained subjects, with vascular endothelial growth factor (VEGF) and eNOS being more highly expressed in trained subjects. Overall, our data suggest an association between the sedentary state and increased nitro-oxidative stress in CD34⁺ cells.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Antigens, CD34 / blood*
  • Cells, Cultured
  • Exercise Test
  • Gene Expression Regulation
  • Glutathione Peroxidase / genetics
  • Humans
  • Immunomagnetic Separation
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism*
  • Male
  • NADPH Oxidases / genetics
  • Nitric Oxide / blood*
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type III / genetics
  • Oxidative Stress* / genetics
  • Physical Endurance*
  • RNA, Messenger / metabolism
  • Sedentary Behavior*
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase-1
  • Superoxides / blood*
  • Time Factors
  • Vascular Endothelial Growth Factor A / genetics
  • Young Adult


  • Antigens, CD34
  • RNA, Messenger
  • SOD1 protein, human
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Superoxides
  • Nitric Oxide
  • glutathione peroxidase GPX1
  • Glutathione Peroxidase
  • NOS2 protein, human
  • NOS3 protein, human
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Superoxide Dismutase
  • Superoxide Dismutase-1
  • superoxide dismutase 2
  • NADPH Oxidases