Objective To observe the effect of electroacupuncture(EA)stimulation of"Quchi"(LI 11)on arterial blood pressure(BP)

sympathetic nerve activity

barorefiex sensitivity(BRS)and expression of brain derived neurotrophic factor(BDNF)and nicotinamide adenine dinucleotide phosphate(NADPH)enzyme subunit p 47 phox in the rostral ventrolateral medulla(RVML)in hypertension rats.Methods A total of 45 male SD rats were randomly divided into sham operation

artificial cerebro-spinal fluid(aCSF)

model

"Quchi"(LI 11)

and Jianyu(LI 15)groups(n=9in each group).The hypertension model was established by microinjection of AngⅡ(200μg·kg-1·day-1)into the lateral ventricle(A-C:1.0mm

L:1.4mm

H:4.5mm)for 2weeks(aCSF for aCSF group).After 1week's AngⅡ perfusion

EA(2Hz/15 Hz

1mA)was applied to bilateral"Quchi"(LI 11)or"Jianyu"(LI 15)for 20 min

once daily for two weeks.The mean arterial pressure(MAP)and heart rate(HR)were detected by using a Non-Invasive Blood Pressure System(tail cuff method).The BRS(BP-to-HR transfer function)was determined by calculating the ratio of HR fluctuation(HR∶HR

between post-and pre-intravenous injection of phenylephrine)/MAP fluctuation(MAP∶MAP

between post-and pre-phenylephrine injection)

the urinary norepinephrine(NE)level in 24 hwas assayed by ELISA.Real-time PCR and Western blot were used to detect the mRNA and protein expression of BDNF and p 47 phox in the RVML region tissue.Results Following modeling

the MAP

HR and 24h-urinary NE levels and p 47 phox mRNA and protein expression levels in the RVML were significantly increased(P<0.01)

and the BRS was decreased significantly(P<0.01).After EA intervention

the MAP

HR and 24h-urinary NE levels and p 47 phox mRNA and protein expression levels in the RVML were considerably lower in the LI 11 group than in the model group(P<0.05)

while the BRS level was markedly increased in the LI 11 group compared with the model group(P<0.05).The expression levels of BDNF mRNA and protein in the RVLM region were obviously up-regulated in the LI 11 group compared with the model group(P<0.05).No significant differences were found between the LI 15 group and the model group in the MAP

HR

24h-urinary NE

BRS

BDNF mRNA and protein and p 47 phox mRNA and protein expression levels(P>0.05).Conclusion EA stimulation of"Quchi"(LI 11)can down-regulate arterial blood pressure

sympathetic nerve activity

and increase the baroreflex sensitivity in hypertension rats

which may be related to its effects in down-regulating p 47 phox mRNA and protein expression in the RVML.