Release of hemopoietic and endothelial progenitors after endurance and maximal exercise in runners.

Release ofbonemarrow-derivedprogenitorsdiffersbetweenendurance(Bon- signore etal,JApplPhysiol2002)andpowerathletes(Moricietal,AmJPhysiol 2005). Weinvestigatedhemopoieticandangiogeneticprogenitorreleaseinrunners after the2005PalermoMarathon(n=9,meanage±SD: 44±12 yr,training:88±35 km/wk) andaftermaximalexercise(1500mrunning,n=7,VO2peak:45±6 ml/min/kg). Venousbloodwasobtainedatrestand5-10minpost-exercise,and hemopoietic progenitorswereevaluatedbyflowcytometry(CD34+,CD133+)and clonogeneticassays(BFU-E,CFU-GM,CFU-GEMM).Angiogeneticprogenitors wereassessedbyflowcytometryasVE-cadherin+CD133+,VEGFR2+CD34+ cells orcirculatingangiogeniccells(CAC).Afterthemarathon,totalCD34+ cells wereunchangedandclonogeneticassaysshoweda50-60%decreaseinthe number ofhemopoieticcolonies.After1500mrunning,CD34+cellsdoubledand BFU-E, CFU-GM,CFU-GEMMincreased.VEGFR2+CD34+cellsincreasedby 1.5-fold afterbothmarathonandmaximalexercise.CACreleasewasmoremarked after themarathon(+333±192%) thanaftermaximalexercise(+162±70%), while release ofVE-cadherin+CD133+cellsshowedanoppositebehaviour(+139±83 vs +285±132%). Thesechangeswereassociatedwithreleaseofangiogeneticgrowth factors.Therefore,intrainedrunnersexercisecausedsignificantmobilizationof angiogeneticprogenitorsmodulatedbyexercisedurationand/orintensity.The results ofclonogeneticassaysshowedthatcirculatinghemopoieticprogenitors increased afteracuteexercisebutdecreasedafterprolongedexercise,suggesting peripheral utilizationofbonemarrow-derivedcellsduringprolongedexercise- related stress.