The effect of brief exercise on circulating CD34+ stem cells in early and late pubertal boys

Abstract

We tested the hypothesis that exercise could stimulate CD34 peripheral blood hematopoietic stem cells (PBSC) in children. Fourteen early pubertal boys (EP, age 10.3 ± 0.3 y) and 13 late pubertal boys (LP, age 16.5 ± 0.4 y) performed 20 min of moderate-to-vigorous cycle ergometer exercise. Blood was drawn before and after exercise. Cells were stained for surface CD34. Plasma granulocyte colony stimulating factor (G-CSF), Fms-like tyrosine kinase-3 (FLT-3), and stromal cell-derived factor-1 (SDF-1) were measured using ELISA. Exercise substantially increased PBSC (in EP from 112 ± 21 to 182 ± 30 cells/μL, p = 0.0007; in LP from 63 ± 8 to 152 ± 21, p = 0.0008), and to a smaller extent FLT-3 (in EP from 98 ± 5 to 110 ± 6 pg/mL, p < 0.0001; in LP from 73 ± 6 to 92 ± 6, p < 0.0001) and G-CSF (in EP from 26 ± 4 to 29 ± 4 pg/mL, p < 0.0001; in LP from 14 ± 1 to 18 ± 1, p < 0.0001). Baseline levels of PBSC, FLT-3, and G-CSF were significantly higher in EP. Exercise increased SDF-1α only in LP, and the FLT-3 increase was greater in LP than EP. Brief exercise affects PBSC and PBSC mediators in children. © International Pediatrics Research Foundation, Inc. 2007. All Rights Reserved.