Objective

2

To observe the effect of

Xingnao Kaiqiao

(regaining consciousness and opening orifices) acupuncture therapy on the local vasodilatation of ischemic stroke rats

so as to elucidate the mechanism of the protective effect of acupuncture on ischemic brain injury.

Methods

2

Eighty SPF-grade male SD rats were randomly divided into a sham-operation group

a model group

an acupuncture group and a zinc chelator (TPEN) group

with 20 rats in each group. Except in the sham-operation group

modified Longa filament method was used to establish rat models of middle cerebral artery occlusion in the other groups. In the sham-o

peration group

the blunt dissection was performed

without the suture occluded. In the acupuncture group

Xingnao Kaiqiao

acupuncture therapy was operated at bilateral "Neiguan" (PC6) and "Shuigou" (GV26)

and the needles were retained for 30 min

once daily

for consecutively 7 days. In the TPEN group

TPEN was injected intraperitoneally (15 mg/kg)

30 min before modeling. The neurobehavioral scores were assessed 2 h and 7 d after modeling respectively. Before modeling

and 2 h and 7 d after modeling

the diameter of blood vessels in the ischemic area of the right cerebral cortex of rats was measured by laser speckle

and the vascular expansion and contraction ratio was calculated. Seven days after modeling

using 2

3

5-triphenyltetrazolium chloride (TTC) staining method

the percentage of cerebral infarction volume was determined in the ischemic area of the right cerebral cortex of rats

FLOUZin-3 fluorescent probe was used to detect the level of Zn

2+

Western blotting and real-time quantitative PCR were adopted to detect the protein and mRNA expression of the vasodilation-related transient receptor potential factor 1 (TRPA1) and calcitonin gene-related peptide (CGRP)

and calcium test kit was used to detect the content of calcium ion (Ca

2+

) in the ischemic area of the right cerebral cortex of rats.

Results

2

Seven days after modeling

compared with the sham-operation group

the neurobehavioral score

the percentage of cerebral infarction volume

the level of Zn

2+

and the contents of Ca

2+

increased (

P

<

0.05)

vascular expansion and contraction ratio was not different statistically (

P

>

0.05)

and the mRNA and protein expression of TRPA1 and CGRP decreased (

P

<

0.05) in the model group. Compared with the model group

the neurobehavioral scores

the percentage of cerebral infarction volume

Zn

2+

levels and Ca

2+

contents were reduced (

P

<

0.05)

vascular expansion and contraction ratio rose (

P

<

0.05)

and the mRNA and protein expression of TRPA1 and CGRP was elevated (

P

<

0.05) in the acupuncture group and the TPEN group. When compared with the TPEN group

the neurobehavioral score and the percentage of cerebral infarction volume were elevated (

P

<

0.05)

and the differences were not significant statistically in Zn

2+

level and Ca

2+

content

vascular expansion and contraction ratio

and the mRNA and protein expression of TRPA1 and CGRP in the acupuncture group (

P

>

0.05).

Conclusion

2

Xingnao Kaiqiao

acupuncture therapy can effectively dilate cerebral blood vessels to alleviate ischemic brain injury

which may be related to reducing the level of free Zn

2+

activating TRPA1 channel to promote Ca

2+

influx

thereby releasing CGRP to induce cerebral vasodilation.