The magnitude of exercise-induced progenitor cell mobilisation and extravasation is positively associated with cardiorespiratory fitness.

Abstract

CD34+ progenitor cells with angiogenic capabilities traffic into blood during exercise and extravasate afterwards but the magnitude of this response varies between people. We examined whether exercise-induced progenitor cell trafficking is influenced by cardiorespiratory fitness (maximum oxygen uptake; ). Ten males (age: 23±3years; : 61.88±4.68mLkgmin-1) undertook 1h of treadmill running at 80% of . Blood samples were collected before exercise (Pre), in the final minute of exercise (0h) and afterwards at 0.25, 1 and 24h. Pan-progenitor cells (CD34+, CD34+CD45dim) and putative endothelial progenitor cells (CD34+CD133+, CD34+VEGFR2+, CD34+CD45dimVEGFR2+) were quantified using flow cytometry. Progenitor subpopulations (except for CD34+CD45dimVEGFR2+) increased at 0h (P<0.05) and returned to pre-exercise levels by 1h. was positively associated with the exercise-induced progenitor cell response and there were statistically significant time × interactions for CD34+, CD34+CD45dim and CD34+CD133+ subpopulations but not VEGFR2-expressing progenitor cells. There were statistically significant correlations between and ingress (r>0.70, P<0.025) and egress (r>-0.77, P<0.009) of progenitor cell subsets (CD34+, CD34+CD45dim, CD34+CD133+), showing that cardiorespiratory fitness influences the magnitude of progenitor cell mobilisation into the blood and subsequent extravasation. These data may provide a link between high levels of cardiorespiratory fitness and vascular health.