Abstract 21197: Exercise Training Restores the Endothelial Progenitor Cells Function and Levels in Hypertension: Role on Skeletal Muscle Neovascularization
Aerobic exercise training (ET) has been established as an important treatment for hypertension, since it counteracts microvascular rarefaction and decreased BP; however, underlying mechanisms remain to be further determined. We investigated for the first time if the endothelial progenitor cells (EPC) levels and the functional capacity, impaired in hypertension; improve after ET potentially contributing to neovascularization and disease regression. The effect of ET on BP, HR, exercise tolerance, peak VO2 and skeletal muscle morphology and biochemistry was studied in twelve-weeks old male Spontaneously Hypertensive Rats (SHR, n=14) and Wistar Kyoto (WKY, n=14) divided into 4 groups: SHR, trained SHR (SHR-T), WKY and trained WKY (WKY-T). The ET decreased BP in SHR and resting HR, increase exercise tolerance, peak VO2 and skeletal muscle citrate synthase activity in trained groups. In parallel, the ET repaired the skeletal muscle fiber type shift and capillary rarefaction in SHR, by enhancing protein levels of VEGF, VEGFR2, eNOS and deactivated apoptosis pathway. Numbers of CD34+/Flk1+ cells circulating in the peripheral blood quantified by fluorescence-activated cell sorter analysis were enhanced 115% in WKY-T of control levels. In contrast, SHR group decreased 39%, but ET normalized in the SHR-T. Similar results were found in the EPC quantification of the bone marrow (BM) by double positive cells to acDiLDL and Lectin. EPC senescence associated β- galactosidase activity was increased 126% in SHR and this process was reduced 72% by ET. Moreover, the functional assay by colony-forming units showed increase of 40% to BM and 70% circulating in WKY-T of control levels. In contrast, SHR group reduced 35% to BM and 45% circulating; however the ET repaired EPC dysfunction in hypertension. In fact, the ET corrected a failure in the capillary-like tube formation in matrigel. The present findings reveal that the vascular remodeling accompanied by reduction of BP induced by ET occurs in synergy with the restoration of the EPC numbers and functional properties to BM and circulating. These results suggest that the ET can participate of the vascular repair by means of the EPC, promoting the peripheral revascularization in hypertension.
- © 2010 by American Heart Association, Inc.