title: Hydrogen peroxide inhibits exercise-induced increase of circulating stem cells with endothelial progenitor capacity.
abstract: The number of circulating stem cells with endothelial progenitor capacity (EPCs) inversely correlates with the number of cardiovascular risk factors. In this study we sought to investigate the effects of vascular H(2)O(2) on circulating EPC levels. In C57BL/6 mice 3 weeks of freely moving or forced physical activity or voluntary exercise failed to increase circulating EPCs defined as double positive for Flk-1 and CD34, CD133 or Sca-1. Likewise, neither insertion of additional genes encoding for catalase (cat(++)) or eNOS nor eNOS knock-out changed EPCs in resting mice. In striking contrast, inhibition of catalase by aminotriazole strongly reduced circulating EPCs in sedentary cat(++) and their transgen-negative littermates (cat(n)), while forced or voluntary exercise training of cat(++) mice significantly increased the number of circulating EPCs. The latter effect was completely inhibitable by aminotriazole. These data suggest that endogenous vascular H(2)O(2) likely contributes to the impairment of important stem cell-induced vascular repair mechanisms in cardiovascular disease.
authors.affiliation: Institute of Pharmacology and Clinical Pharmacology, Heinrich Heine University, 40225 Duesseldorf, Germany. tasuv@gmx.de
authors.forename: Tatsiana
authors.initials: T
authors.lastname: Suvorava
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kumpf
authors.forename: Bernhard H
authors.initials: BH
authors.lastname: Rauch
authors.forename: Vu Thao-Vi
authors.initials: VT
authors.lastname: Dao
authors.forename: Volker
authors.initials: V
authors.lastname: Adams
authors.forename: Georg
authors.initials: G
authors.lastname: Kojda
mesh_terms: D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010805:Physical Conditioning, Animal / Q000502:physiology*
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase; D000640:Amitrole