Objective To observe the effect of mustard oil application at “Liangmen”(ST21) on gastric ulcer(GU) and gastric motility and its association with the sympathetic nerve activity in rats with GU

so as to provide experimental basis for improvement of GU by acupoint application. Methods Thirty-nine male SD rats were randomly divided into control(n=7)

model

acupoint application(AA)

medication(guanethidine

an adrenergic sympathetic antagonist) and AA+medication groups(n=8 in each of the latter 4 groups). The GU model was made by applying acetic acid-immersed filter paper onto the gastric antrum. For rats of the AA and AA+medication groups

50% mustard oil was applied to left ST21 for 10 min

once a day

for 9 consecutive days. Rats of the medication and AA+medication groups received intraperitoneal injection of guanethidine solution(40 mg/kg) beginning from the modeling day on

once a day for 10 consecutive days. The rat's body weight of each group was recorded on the 0

(th)

1(th)

1

(st)

3(st)

3

(rd)

7(rd)

7

(th)

and 9(th) and 9

(th)

day. The intragastric peristaltic wave frequency and the myoelectrical activity(frequency of slow waves

and integration of fast waves) of the gastric smooth muscle were recorded by using PowerLab data acquisition system. The gastric ulcer area was measured after the rats were executed

and histopathological changes of gastric antrum tissues(histopathological score including epithelial cell injury

submucosal edema

hemorrhagic injury

inflammatory cell infiltration score) were observed after H.E. staining. Results Compared with the control group

the body weight ratio

frequency of gastric peristaltic waves and slow wave frequency of gastric smooth muscle were significantly decreased(P

<

0.001

P

<

0.05)

while the ulcer area

total histopathological score

epithelial cell injury score

submucosal edema score

hemorrhagic injury score and inflammatory cell infiltration score were significantly increased in the model group(P

<

0.05

P

<

0.001). Relevant to the model group

the AA group had a significant increase in the body weight ratio

frequency of gastric peristaltic waves

slow wave frequency

integration of fast waves(P

<

0.05

P

<

0.001)

and a considerable decrease in the ulcer area

total histopathological score

epithelial cell injury score

submucosal edema score

hemorrhagic injury score and inflammatory cell infiltration score(P

<

0.05

P

<

0.001)

and the medication group has a significantly decrease in the frequency of gastric peristaltic waves(P

<

0.05). In comparison with the AA group

the body weight ratio

frequency of gastric peristaltic waves and slow wave frequency of gastric smooth muscle in both medication and AA+medication groups

and the integration of fast waves in the medication group were obviously lower(P

<

0.05

P

<

0.001

P

<

0.01)

whereas the levels of ulcer area

total pathological score

submucosal edema score

hemorrhagic injury score and inflammatory cell infiltration score in both medication and AA+medication groups

and the epithelial cell injury score in medication group were significantly higher(P

<

0.05

P

<

0.001). Conclusion Application of mustard oil at acupoint ST21 can effectively remit GU caused by acetic acid and regulate gastric rhythmic contraction

which was mediated by sympathetic nerve.