Differences in Post-ischemic Motor Recovery and Angiogenesis of MCAO Rats Following Electroacupuncture at Different Acupoints

Abstract

Background: Electroacupuncture (EA) can promote nerve and vascular regeneration, confer neuroprotection, inhibit apoptosis and inflammatory reactions, reduce oxidative stress injury, regulate neurochemicals and inhibit the formation of brain oedema in cerebral ischemic. However, the precise site of EA stimulation in the treatment of cerebral ischemic is unclear.

Objective: In the present study, we investigated the effect of EA at the acupoints of different meridians in motor function recovery and the involvement of Vascular Endothelial Growth Factor (VEGF), phosphorylated Protein Kinase B (P-Akt), phosphorylated endothelial nitric oxide synthase (p-eNOS) and Platelet Endothelial Cell Adhesion Molecule-1(CD31) were examined in the peri-infarction cortex of rats.

Methods: The Middle cerebral artery occlusion (MCAO) model or sham surgery was performed in a total of Ninety male Sprague-Dawley rats. Rats were randomly divided into five groups: a sham group, a middle cerebral artery occlusion (MCAO) group, a Yang meridian group, a Yin meridian group and a combined Yang and Yin meridian group. EA stimulus was given during the middle cerebral artery occlusion. The neurobehavioural function was measured using Modified Neurological Severity Scores (mNSS), the rotarod test and the ladder rung walking test, and the protein expression of VEGF, P-Akt, p-eNOS in the peri-infarction cortex was detected by Western blot. Immunofluorescence was used to measure the vascular density of the peri-infarction cortex.

Results: EA at different meridian acupoints has no effect on the infarction volume, while EA at Yin meridian acupoints significantly promoted neurobehavioural functional recovery, increased the vascular density and enhanced protein kinase B/Endothelial nitric oxide synthase (Akt/eNOS) phosphorylation and VEGF expression.

Conclusion: In the early stage of stroke, EA at Yin meridian acupoints can improve neurobehavioural functional recovery and the mechanism of this effect may be related to the enhanced expression of VEGF, P-Akt and p-eNOS in the peri-infarction cortex of rats.

Keywords: Middle cerebral artery occlusion; Yang meridian; Yin meridian; angiogenesis; electroacupuncture; endothelial nitric oxide synthase..