Repeated bouts of moderate-intensity aerobic exercise reduce airway reactivity in a murine asthma model

Am J Respir Cell Mol Biol. 2010 Feb;42(2):243-9. doi: 10.1165/rcmb.2009-0038OC. Epub 2009 May 7.


We have reported that moderate-intensity aerobic exercise training attenuates airway inflammation in mice sensitized/challenged with ovalbumin (OVA). The current study determined the effects of repeated bouts of aerobic exercise at a moderate intensity on airway hyperresponsiveness (AHR) in these mice. Mice were sensitized/challenged with OVA or saline and exercised at a moderate intensity 3 times/week for 4 weeks. At protocol completion, mice were analyzed for changes in AHR via mechanical ventilation. Results show that exercise decreased total lung resistance 60% in OVA-treated mice as compared with controls; exercise also decreased airway smooth muscle (ASM) thickness. In contrast, exercise increased circulating epinephrine levels 3-fold in saline- and OVA-treated mice. Because epinephrine binds beta(2)-adrenergic receptors (AR), which facilitate bronchodilatation, the role of beta(2)-AR in exercise-mediated improvements in AHR was examined. Application of the beta(2)-AR antagonist butoxamine HCl blocked the effects of exercise on lung resistance in OVA-treated mice. In parallel, ASM cells were examined for changes in the protein expression of beta(2)-AR and G-protein receptor kinase-2 (GRK-2); GRK-2 promotes beta(2)-AR desensitization. Exercise had no effect on beta(2)-AR expression in ASM cells of OVA-treated mice; however, exercise decreased GRK-2 expression by 50% as compared with controls. Exercise also decreased prostaglandin E(2) (PGE(2)) production 5-fold, but had no effect on E prostanoid-1 (EP1) receptor expression within the lungs of OVA-treated mice; both PGE(2) and the EP1 receptor have been implicated in beta(2)-AR desensitization. Together, these data indicate that moderate-intensity aerobic exercise training attenuates AHR via a mechanism that involves beta(2)-AR.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aerobiosis
  • Airway Resistance / physiology
  • Allergens / administration & dosage
  • Animals
  • Asthma / pathology
  • Asthma / physiopathology
  • Asthma / therapy*
  • Dinoprostone / metabolism
  • Disease Models, Animal
  • Epinephrine / blood
  • Female
  • G-Protein-Coupled Receptor Kinase 2 / metabolism
  • Lung / immunology
  • Lung / metabolism
  • Lung / pathology
  • Mice
  • Mice, Inbred BALB C
  • Muscle, Smooth / pathology
  • Ovalbumin / administration & dosage
  • Ovalbumin / immunology
  • Physical Conditioning, Animal / methods*
  • Receptors, Adrenergic, beta-2 / metabolism
  • Receptors, Prostaglandin E / metabolism
  • Receptors, Prostaglandin E, EP1 Subtype
  • Respiratory Hypersensitivity / physiopathology
  • Respiratory Hypersensitivity / therapy


  • Allergens
  • Ptger1 protein, mouse
  • Receptors, Adrenergic, beta-2
  • Receptors, Prostaglandin E
  • Receptors, Prostaglandin E, EP1 Subtype
  • Ovalbumin
  • GRK2 protein, mouse
  • G-Protein-Coupled Receptor Kinase 2
  • Dinoprostone
  • Epinephrine