Electroacupuncture combined with rehabilitation training improves regional cerebral blood flow and reduces infarct volume by promoting expression of angiogenesis-related factors in acute cerebral ischemia rats

Abstract

To observe the effect of electroacupuncture (EA) combined with rehabilitation training on regional cerebral blood flow (rCBF) and angiogenesis in rats with acute cerebral ischemia (ACI), so as to explore its mechanisms underlying improvement of ACI. A total of 135 male SD rats were divided into 5 groups: sham-operation (sham), model, EA, rehabilitation training and EA+rehabilitation training (combined treatment) groups (n=27 rats in each group). The ACI model was established by occlusion of the middle cerebral artery with thread embolus. EA (2 Hz/20 Hz, 3-5 V) was applied to "Baihui" (GV20), "Shuigou" (GV26) and bilateral "Neiguan" (PC6) for 20 min, once daily for 14 days. The rehabilitation training including hair-brushing in an enriched environment (10 min), round wooden-stick turning (10 min), grid-board climbing (10 min), and treadmill running (30 min/d) was condacted once daily for 14 days. The rCBF was measured by Doppler ultrasound. The cerebral infarct volume (CIV) was measured after 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The expression of CD34+ in the ischemic penumbra region of brain tissue was detected by immunohistochemistry, and the expressions of angiogenesis-related factors as vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2) and basic fibroblast growth factor (bFGF) proteins in the ischemic brain tissue were detected by Western blot. Following modeling, the rCBF levels at the 5 min, 3rd, 7th and 14th day were significantly decreased in the model group relevant to the sham group (P<0.01). After the intervention, the rCBF levels were significantly increased on day 3, 7 and 14 in the combined treatment group and on day 7 and 14 in both the EA and rehabilitation training groups in comparison with the model group (P<0.01). The CIV was obvious in the model group in comparison with the sham group (P<0.01), but was markedly smaller in the EA, rehabilitation training and combined treatment groups on day 3,7 and 14 than in the model group (P<0.01). The number of CD34+ positive cells, and the expression levels of VEGF, VEGFR2, and bFGF proteins in ischemic brain tissues were significantly higher on day 3, 7 and 14 in the model group than in the sham group (P<0.01, P<0.05), and were further up-regulated considerably at the 3 time-points in the 3 treatment groups (P<0.01, P<0.05). The therapeutic effect of EA+rehabilitation training was significantly superior to that of simple EA and simple rehabilitation training in up-regulating rCBF, CD34+ positive cell number, and expression levels of VEGF, VEGFR2 and bFGF, and in down-regulating the CIV on day 3,7 and 14 (P<0.05, P<0.01). No significant differences were found between the EA and rehabilitation groups in the above-mentioned 6 indexes (P>0.05). EA combined with rehabilitation training can reduce the infarct volume and increase rCBF in ACI rats, which is probably associated with its effects in promoting the expression of angiogenesis-related factors of ischemic brain tissues. The effect of EA combined with rehabilitation training is markedly better than that of EA and rehabilitation training alone.