The elucidation of the mechanisms of cardiovascular hypertrophy and hyperplasia and the establishment of angiogenesis by therapeutic electrical stimulation

点击翻译按钮获取中文摘要

Low voltage electrical stimulation (LVES) of skeletal muscle at a level far below the threshold of muscle contraction has been reported to induce synthesis of VEGF. We examined whether LVES induced VEGF production in hindlimb ischemia model of rats was due to hypoxia or inflammation. We also tried to evaluate whether other angiogenic factors, such as hepatocyte growth factor (HGF) and fibroblast growth factor (FGF), also contribute to the local angiogenesis by LVES. Thirdly we compared the effect of LVES with that of high VES (HVES) on the induction of angiogenic factors.Not only VEGF but also HGF was significantly increased in tissues by LVES. There was no difference in the level of immunohistochemical staining of the tibialis anterior (TA) muscles with polyclonal anti FGF antibody, anti IL6 antibody, and HIF antibody between the LVES group and control group. The VEGF level of the intermittent HVES group tended to be higher than that of the continuous LVES or intermittent LVES groups although the difference was not significant. Therefore, not only VEGF but also HGF may contribute to the local angiogenesis by LVES in this model. It was also demonstrated that the LVES-induced VEGF production in this model may not be due to hypoxia or inflammation by LVES. Thirdly, we demonstrated that the induction of VEGF by LVES was seen at a significantly earlier period than that by HVES and that the increase in the ratio of VEGF synthesis of stimulated to control by LVES was smaller than that by HVES comparing between 1 day and 5 days.In conclusion, continuous LVES in a hindlimb ischemia model of rats was effective for VEGF and HGF induction which was not seen on high voltage stimulation, and ES might be useful for ischemic disease even at low voltage.