Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise

The effects of endurance or maximal exercise on mobilization of bone marrow-derived hemopoietic and angiogenetic progenitors in healthy subjects are poorly defined. In 10 healthy amateur runners, we collected venous blood before, at the end of, and the day after a marathon race (n = 9), and before and at the end of a 1.5-km field test (n = 8), and measured hemopoietic and angiogenetic progenitors by flow cytometry and culture assays, as well as plasma or serum concentrations of several cytokines/growth factors. After the marathon, CD34(+) cells were unchanged, whereas clonogenetic assays showed decreased number of colonies for both erythropoietic (BFU-E) and granulocyte-monocyte (CFU-GM) series, returning to baseline the morning post-race. Conversely, CD34(+) cells, BFU-E, and CFU-GM increased after the field test. Angiogenetic progenitors, assessed as CD34(+)KDR(+) and CD133(+)VE-cadherin(+) cells or as adherent cells in culture expressing endothelial markers, increased after both endurance and maximal exercise but showed a different pattern between protocols. Interleukin-6 increased more after the marathon than after the field test, whereas hepatocyte growth factor and stem cell factor increased similarly in both protocols. Plasma levels of angiopoietin (Ang) 1 and 2 increased after both types of exercise, whereas the Ang-1-to-Ang-2 ratio or vascular endothelial growth factor-A were little affected. These data suggest that circulating hemopoietic progenitors may be utilized in peripheral tissues during prolonged endurance exercise. Endothelial progenitor mobilization after exercise in healthy trained subjects appears modulated by the type of exercise. Exercise-induced increase in growth factors suggests a physiological trophic effect of exercise on the bone marrow.