Supramaximal exercise mobilizes hematopoietic progenitors and reticulocytes in athletes.
Marathon runners show increased circulating CD34+ cell counts and postexercise release of interleukin-6 (IL-6), granulocyte-colony stimulating factor (G-CSF) and flt3-ligand (Bonsignore MR, Morici G, Santoro A, Pegano M, Cascio L, Bonnano A, Abate P, Mirabella F, Profita M, Insalaco G, Gioia M, Vignola AM, Majolino I, Testa U, and Hogg JC. J Appl Physiol 93: 1691-1697, 2002). In the present study we hypothesized that supramaximal ("all-out") exercise may acutely affect circulating progenitors and reticulocytes and investigated possible mechanisms involved. Progenitor release was measured by flow cytometry (n = 20) and clonogenic assays (n = 6) in 20 young competitive rowers (13 M, 7 F, age +/- SD: 17.1 +/- 2.1 yr, peak O2 consumption: 56.5 +/- 11.4 ml.min(-1).kg(-1)) at rest and shortly after 1,000 m "all-out." Release of reticulocytes, cortisol, muscle enzymes, neutrophil elastase, and several cytokines/growth factors was measured. Supramaximal exercise doubled circulating CD34+ cells (rest: 7.6 +/- 3.0, all-out: 16.3 +/- 9.1 cells/mul, P < 0.001), and increased immature reticulocyte fractions; AC133+ cells doubled, suggesting release of angiogenetic precursors. Erythrocyte burst forming units and colony forming units for granulocytes-monocytes and all blood series increased postexercise by 3.4-, 5.5-, and 4.8-fold, respectively (P < 0.01 for all). All-out rowing acutely increased plasma cortisol, neutrophil elastase, flt3-ligand, hepatocyte growth factor, VEGF, and transforming growth factor-beta1, and decreased erythropoietin; K-ligand, stromal-derived factor-1, IL-6, and G-CSF were unchanged. Therefore, all-out exercise is a physiological stimulus for progenitor release in athletes. Release of reticulocytes and proangiogenetic cells and mediators suggests tissue hypoxia as possibly involved in progenitor mobilization.
Morici
Giuseppe
G
Department of Experimental Medicine, University of Palermo, Italy.
Zangla
Daniele
D
Santoro
Alessandra
A
Pelosi
Elvira
E
Petrucci
Eleonora
E
Gioia
Maria
M
Bonanno
Anna
A
Profita
Mirella
M
Bellia
Vincenzo
V
Testa
Ugo
U
Bonsignore
Maria R
MR
D000293:Adolescent; D000328:Adult; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000097:blood; D004921:Erythropoietin / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood; D006098:Granulocytes / Q000502:physiology; D006133:Growth Substances / Q000097:blood; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D019272:Leukocyte Elastase / Q000097:blood; D008297:Male; D009000:Monocytes / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D012156:Reticulocytes / Q000166:cytology* / Q000502:physiology*
D016207:Cytokines; D006133:Growth Substances; D004921:Erythropoietin; D016179:Granulocyte Colony-Stimulating Factor; D019272:Leukocyte Elastase; D006854:Hydrocortisone