title: Circulating progenitor cells decrease immediately after marathon race in advanced-age marathon runners.
abstract: BACKGROUND
  Exercise is thought to stimulate the release of hematopoietic and endothelial progenitor cells (EPC) from the bone marrow. Little is known about the influence of strenuous exercise on the content of circulating progenitor cells. The aim of this study was to investigate the influence of a marathon race on the amount of circulating progenitor cells immediately after the race in advanced-aged runners.
  
  
  METHODS
  Sixty-eight healthy marathon runners (age: 57+/-6 years) were included in this study. Blood cell counts were evaluated by standard methods, and circulating progenitor cells before and immediately after the race were quantified by fluorescence-activated cell sorter (FACS). Vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) was quantified by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  A marathon race led to a significant increase in white blood cell count (5283+/-155 vs. 13706+/-373 cells/mul; P<0.001). Fluorescence-activated cell sorter analysis revealed a significant decrease of CD34 cells (1829+/-115 vs. 1175+/-75 cells/ml blood; P<0.0001), CD117 cells (2478+/-245 vs. 2193+/-85 cells/ml blood; P<0.05), and CD133 cells (3505+/-286 vs. 2239+/-163 cells/ml blood; P<0.001). No significant change was observed for EPCs defined as CD34/VEGF-R2 cells (117+/-8 vs. 128+/-9 cells/ml blood; P=0.33). With respect to VEGF a significant downregulation was evident directly after the race (48.9+/-8.0 vs. 34.0+/-7.5 pg/ml; P<0.05), whereas no change was obvious in EGF levels.
  
  
  CONCLUSIONS
  The results of our study suggest that finishing a marathon race will lead to an inflammatory response and downregulation of circulating hematopoietic stem cells. With respect to EPCs no change is observed, which may be because of a greater differentiation of the remaining CD34 cells towards EPCs.
authors.affiliation: Department of Cardiology, University Leipzig-Heart Center, Leipzig, Germany. adav@medizin.uni-leipzig.de
authors.forename: Volker
authors.initials: V
authors.lastname: Adams
authors.forename: Axel
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authors.lastname: Linke
authors.forename: Frank
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authors.lastname: Breuckmann
authors.forename: Kirsten
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authors.forename: Sandra
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authors.lastname: Erbs
authors.forename: Nicolle
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authors.lastname: Kränkel
authors.forename: Martina
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authors.lastname: Bröcker-Preuss
authors.forename: Felix
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authors.lastname: Woitek
authors.forename: Raimund
authors.initials: R
authors.lastname: Erbel
authors.forename: Gerd
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authors.lastname: Heusch
authors.forename: Rainer
authors.initials: R
authors.lastname: Hambrecht
authors.forename: Gerhard
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authors.lastname: Schuler
authors.forename: Stefan
authors.initials: S
authors.lastname: Möhlenkamp