2022, Vol. 26 ›› Issue (5): 663-668
Effects of electroacupuncture at Zusanli acupoint on visceral hypersensitivity in rats with functional dyspepsia
The pathogenesis of functional dyspepsia is complex, and visceral hypersensitivity is one of the most important pathological mechanisms. However, there are few reports on electroacupuncture treatment of functional dyspepsia from the perspective of visceral hypersensitivity mechanism.
To observe the effects and its possible mechanism of electroacupuncture at Zusanli (ST36) on visceral hypersensitivity in rats with functional dyspepsia.
Twenty-four 7-day-old male Sprague-Dawley rats were randomly divided into three groups: a control group, a model group, and an electroacupuncture group (n=8). The visceral hypersensitivity model of functional dyspepsia rats was prepared with multi-factor stress methods (intragastric administration of iodoacetamide+irregular feeding+Guo’s moderate clipping tail). In the electroacupuncture group, rats aged 8 weeks were treated with electroacupuncture intervention. A disposable sterile acupuncture needle was pierced into 7-10 mm at Zusanli acupoints of bilateral hind limbs of rats, which was connected with Hans-acupoint nerve stimulator (dilatational wave, 2/100 Hz, 1 mA). Electroacupuncture was performed 20 minutes per day, 5 consecutive days as one session with 2 days off, for 2 sessions in total. The average body mass of rats in different stages was computed. Mechanical pain threshold of the plantar was tested to detect visceral sensitivity of rats. Enzyme-linked immune sorbent assay (ELISA) was applied to detect the level of 5-hydroxytryptamine in serum and gastric fundus mucosa tissue. Real-time fluorescence quantitative PCR was used to assess the expression of exchange protein 1 directly activated by cAMP (EPAC1) and PIEZO2 mRNA in gastric fundus mucosa tissue.
Compared with the control group, the average body mass and plantar mechanical pain threshold were significantly decreased in the model group, and the level of 5-hydroxytryptamine in serum and gastric fundus mucosa was significantly increased (all P < 0.01). The mRNA expression levels of EPAC1 and PIEZO2 in gastric fundus mucosa were significantly increased in the model group compared with the control group (P < 0.01). Compared with the model group, in the electroacupuncture group, the average body mass and plantar mechanical pain threshold were significantly increased after 7 and 14 days of treatment (P < 0.05, P < 0.01), while the mRNA expression levels of EPAC1 and PIEZO2 in gastric fundus mucosa were significantly decreased (P < 0.01). These findings indicate that electroacupuncture at Zusanli can significantly improve the visceral hypersensitivity of functional dyspepsia rats, which is possibly mediated by regulating the release of 5-hydroxytryptamine from enterochromaffin cells and the mRNA expression of EPAC1 and PIEZO2.
functional dyspepsia, electroacupuncture, visceral hypersensitivity, exchange protein 1 directly activated by cAMP, PIEZO2, rat