Objective To observe the effect of “Tiaoshen Tongluo” acupuncture(TTA) at “Dingzhongxian”(MS5) and right “Dingpangxian”(MS8) on neurological injury

muscle tension and neurotransmitters through nuclear transcription factor E2 related factor 2(Nrf2)/reactive oxygen species(ROS) signaling pathway in spastic rats after stroke

so as to explore its mechanisms underlying relief of post-stroke spasm(PSS). Methods A total of 90 male SD rats were randomly divided into 6 groups

i.e. sham operation

PSS model

medication

non-acupoint acupuncture

TTA

TTA+ML385 groups

with 15 rats in each group. The PSS model was established by middle cerebral artery occlusion. After modeling

rats of the medication group were treated by gavage of baclofen(0.4 mg/kg)

once daily for 7 days. For rats of the non-acupoint acupuncture group

the spot about 10 mm above the iliac crest and below the armpit of the affected side was needled

and for those of the TTA group and TTA+ML385 group

EA stimulation(1 mA

2 Hz/15 Hz) was applied to MS5 and right MS8 for 10 min

once daily for 7 consecutive days. Intraperitoneal injection of ML385 [ a specific nuclear factor erythroid 2-related factor 2(Nrf2) inhibitor

30 mg/kg] was given to rats of the TTA+ML385 group before TTA was performed. The rats' neurological deficit score(0—4 points) was evaluated by referring to Zea Longa's methods and the muscular spasm degree of the quadriceps femoris of the left hindlimb(0—4 points) assessed by using Ashworth scale(MAS). The muscular tension of the left quadriceps femoris was measured by using a tension sensor

and Hoffman(H)-reflex response and M and H waves of electromyogram of the muscle between the metatarsals of the left foot were measured using an electrophysiological recorder. The cerebral infarction volume was measured after 2

3

5-triphenyltetrazolium chloride(TTC) staining. The contents of γ-aminobutyric acid(GABA)

glycine(Gly)

glutamic acid(Glu) and aspartic acid(Asp) of the right cortical infarct area were detected by using high performance capillary electrophoresis

and the contents of 5-hydroxytryptamine(5-HT)

dopamine(DA) and norepinephrine(NE) were detected by fluorescence spectrophoto-metry

as well as the level of ROS in the right cerebral cortical infarction tissues was detected by dihydroethidium staining. The expression levels of Nrf2 and heme oxygenase-1(HO-1) proteins in the infarcted cerebral area were detected using Western blot. Results Compared with the sham operation group

the neurological deficit score

MAS score

percentage of cerebral infarction volume

Hmax/Mmax ratio

contents of Glu and Asp and ROS level were significantly increased(P<0.001)

whereas the muscle tone

stimulation threshold for inducing H-reflex

GABA

Gly

5-HT

DA and NE contents

cerebral Nrf2 and HO-1 protein expression levels were apparently decreased(P<0.001) in the model group. In comparison with the model group

the neurological deficit score

MAS score

percentage of cerebral infarction volume

Hmax/Mmax ratio

contents of Glu

Asp and ROS levels were decreased(P<0.001)

and the muscle tone

stimulation threshold for inducing H-reflex

GABA

Gly

5-HT

DA and NE contents

Nrf2 and HO-1 protein expressions were increased(P<0.001

P<0.01) in both the medication and TTA groups. No significant differences were found between the non-acupoint group and model group

and between the medication and TTA groups in all the indexes mentioned above(P>0.05). After administration of ML385

the effects of TTA in reducing neurological deficit score

MAS score

Hmax/Mmax

percentage of cerebral infarct volume

Glu

Asp

ROS

and up-regulating H-reflex threshold

GABA

Gly

5-HT

DA

NE

Nrf2 and HO-1 levels were eliminated(P<0.001

P<0.05

P<0.01). Conclusion TTA can improve neurological behavior and muscle spasm in rats with PSS

which may be associated with its functions in regulating the levels of neurotransmitters in the cortical infarcted area by activating the Nrf2/ROS signaling pathway.