title: Circulating hematopoietic progenitor cells in runners.
abstract: Because endurance exercise causes release of mediators and growth factors active on the bone marrow, we asked whether it might affect circulating hematopoietic progenitor cells (HPCs) in amateur runners [n = 16, age: 41.8 +/- 13.5 (SD) yr, training: 93.8 +/- 31.8 km/wk] compared with sedentary controls (n = 9, age: 39.4 +/- 10.2 yr). HPCs, plasma cortisol, interleukin (IL)-6, granulocyte colony-stimulating factor (G-CSF), and the growth factor fms-like tyrosine kinase-3 (flt3)-ligand were measured at rest and after a marathon (M; n = 8) or half-marathon (HM; n = 8). Circulating HPC counts (i.e., CD34(+) cells and their subpopulations) were three- to fourfold higher in runners than in controls at baseline. They were unaffected by HM or M acutely but decreased the morning postrace. Baseline cortisol, flt3-ligand, IL-6, and G-CSF levels were similar in runners and controls. IL-6 and G-CSF increased to higher levels after M compared with HM, whereas cortisol and flt3-ligand increased similarly postrace. Our data suggest that increased HPCs reflect an adaptation response to recurrent, exercise-associated release of neutrophils and stress and inflammatory mediators, indicating modulation of bone marrow activity by habitual running.
authors.affiliation: Institute of Respiratory Pathophysiology, National Research Council, 90146 Palermo, Italy. marisa@ifr.pa.cnr.it
authors.forename: Maria R
authors.initials: MR
authors.lastname: Bonsignore
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Morici
authors.forename: Alessandra
authors.initials: A
authors.lastname: Santoro
authors.forename: Maria
authors.initials: M
authors.lastname: Pagano
authors.forename: Lucia
authors.initials: L
authors.lastname: Cascio
authors.forename: Anna
authors.initials: A
authors.lastname: Bonanno
authors.forename: Pietro
authors.initials: P
authors.lastname: Abate
authors.forename: Franco
authors.initials: F
authors.lastname: Mirabella
authors.forename: Mirella
authors.initials: M
authors.lastname: Profita
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Insalaco
authors.forename: Maria
authors.initials: M
authors.lastname: Gioia
authors.forename: A Maurizio
authors.initials: AM
authors.lastname: Vignola
authors.forename: Ignazio
authors.initials: I
authors.lastname: Majolino
authors.forename: Ugo
authors.initials: U
authors.lastname: Testa
authors.forename: James C
authors.initials: JC
authors.lastname: Hogg
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000032:analysis; D001772:Blood Cell Count; D001773:Blood Cells / Q000166:cytology* / Q000276:immunology; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008565:Membrane Proteins / Q000097:blood; D008875:Middle Aged; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology; D012016:Reference Values; D012420:Running / Q000502:physiology*; D013997:Time Factors
chemical_list: D018952:Antigens, CD34; D015850:Interleukin-6; D008565:Membrane Proteins; C084881:flt3 ligand protein; D016179:Granulocyte Colony-Stimulating Factor; D006854:Hydrocortisone