Effects Of Aerobics On Angiogenesis In Cardiac Tissue Of Rats Induced By Endothelial Progenitor Cells

Objective Endothelial progenitor cells derived from bone marrow and peripheral blood of male rats, which via aerobic exercise, were cultured in vitro. Then, we investigated the status of proliferative and adherent capacity of endothelial progenitor cells to understand the change and the mechanism on angiogenesis in cardiac tissue of rats.Method The subjects were 20 male Sprague-Dawley rats in age 2 months, which randomly and averagely divided into 2 groups, such as control group and aerobics group. Incremental treadmill exercise with the intensity of aerobic exercise was regarded as aerobics model, and training one a day from Monday to Saturday till 8 weeks. Mononuclear cells from bone marrow and peripheral blood were obtained by density gradient centrifugation 12 hours after the scheme has ended up. The cells were suspended in conditioned medium EGM-2 for culturing in vitro. Their phenotypes were confirmed by uptake of acetylated LDL and binding of fluorescein isothiocyanate (FITC)-labeled Ulex europaeus agglutinin 1 (UEA-1) lectin. Inverted microscope observation was used to understand the morphological changes of endothelial progenitor cells and to calculate cells count, so that the proliferation situation and adherent capability of endothelial progenitor cells was known. CD34 immunohistochemical technology was applied to locate the site of microvessel, and AC 133 immunohistochemical and computer image processing technology were use to detect the expression of AC 133 protein in rats'cardiac muscle. Flow cytometry was applied to exam CD34+and CD34+/Flk-1+cells from peripheral blood mononuclear cells.Results (1) CD34 could preferably display microvessel in cardiac muscle. More CD34 protein (P<0.05) and AC133 protein (P<0.01) were detected on microvessel in aerobics group than those in control group.(2) The percentage of CD34+cells from peripheral blood in group aerobics was higher (P<0.01), and the percentage of CD34+/Flk-1+cells from the same way was not statistically significant compared with control group (P>0.05).(3) The double positive attached cells for Dil-ac-LDL and UEA-1 are endothelial progenitor cells in differentiating.(4) No matter at 48-hour or at day 7, number of attached cells in group aerobics, from both bone marrow and peripheral blood, were more than those in group control (P<0.05).(5) Attached cells in control group, from both bone marrow and peripheral blood, proliferated obviously (P<0.01). Furthermore, in group aerobics, attached cells from both bone marrow proliferated (P<0.01), while those from peripheral blood proliferated too (P<0.05).(6) At day 10, adherent cells from group aerobics were more significantly than those from group control (P<0.01).Conclusion (1) Mobilization, proliferation and adherence of endothelial progenitor cells from bone marrow in rats can be promoted by aerobic exercise.(2) Aerobic exercise could increase stem cells from peripheral blood and could improve proliferative and adherent capacity of endothelial progenitor cells.(3) Endothelial progenitor cells'homing caused angiogenesis in cardiac muscle from aerobics group.(4) Aerobic exercise promoted angiogenesis in cardiac muscle of rats.(5) That endothelial progenitor cells, from bone marrow in rats, whose mobilization, proliferation and adherence could be facilitated by aerobic exercise, increasingly released to peripheral blood and homed to microvessel in cardiac muscle of rats to guide angiogenesis, might be the mechanism of angiogenesis in cardiac muscle of rats through aerobic exercise.