The importance of physiologic ischemia training in preventing the development of atherosclerosis: the role of endothelial progenitor cells in atherosclerotic rabbits

OBJECTIVE: The aim of this study was to investigate the effects of physiologic ischemia training (PIT) on the proliferation of endothelial progenitor cells (EPCs) and the corresponding changes in the influencing factors in atherosclerotic rabbits, including vascular endothelial growth factor (VEGF) and nitric oxide (NO). MATERIALS AND METHODS: Eighteen rabbits were assigned randomly to three groups: a high-fat diet (HD) group, an HD-with-training (HT) group, and a control group. Rabbits in the HD and HT groups were fed high-fat food and those in the HT group were administered PIT from the seventh week onward. Atherosclerotic plaques in the thoracic aorta were stained with Oil Red O and measured by Image-Pro Plus 6.0; VEGF expression was measured using an enzyme-linked immunosorbent assay and real-time PCR to determine both protein and mRNA levels. EPCs were counted using a fluorescence-activated cell sorter; NO in plasma was measured by the Griess reaction; and the levels of blood lipids were measured using a biochemical analyzer. RESULTS: More lipid-containing lesions were found in the HD group than in the HT group (P<0.01), whereas atherosclerotic plaques were not observed in the control group. In addition, the expression of VEGF, production of NO, and levels of blood lipids were consistent with the proportion of plaques. It is noteworthy that the proliferation of EPCs increased in the HT group throughout the 10 weeks, whereas those in the control and HD groups increased in the first 6 weeks and declined during the 10th week (P<0.01). CONCLUSION: PIT may prevent the development of aortic atherosclerosis by promoting the proliferation of EPCs in atherosclerotic rabbits.