Objective

2

To observe the immediate regulatory effect of electroacupuncture (EA) on gastric motility via the vagus nerve in mice with diabetic gastroparesis (DGP)

and to explore the potential central mechanism related to vagus nerve underlying the effects of acupoints.

Methods

2

A total of 27 male C57BL/6 mice of clean grade were selected. Of them

12 mice were randomly divided into a control group 1 and a model group 1

6 mice in each group. In the two groups

EA was applied at "Zusanli" (ST36)

"Neiguan" (PC6) and "Zhongwan" (CV12)

and the intragastric pressure-related indexes were detected. After subdiaphragmatic vagus nerve transection (sVX)

the same EA stimulation was delivered

and the intragastric pressure-related indexes were detected again in the two groups. The remaining 15 mice were randomly divided into a control group 2

a model group 2

a Zusanli group

a Neiguan group and a Zhongwan group

3 mice in each group. In the Zusanli group

the Zhongwan group and the Neiguan group

EA was applied at "Zusanli" (ST36)

"Zhongwan" (CV12) and "Neiguan" (PC6)

respectively

the number of activated choline acetyltransferase (ChAT) neurons in the dorsal motor nucleus of the vagus nerve (DMV) was detected by immunofluorescence staining. Except the control groups 1 and 2

in the remaining groups

diabetes model was established by intraperitoneal injection of streptozotocin (120 mg/kg) combined with high-fat diet feeding. Eight weeks into modeling

the gastric emptying rate was measured to verify the DGP model establishment. Continuous wave was adopted for all EA interventions

of a frequency of 10 Hz and a current of 1 mA.

Results

2

Compared with the control group 1

the fasting blood glucose was increased (

P

<

0.001)

the body weight was increased 8 weeks into modeling (

P

<

0.01)

the gastric emptying rate was decreased (

P

<

0.001) in the model group 1. Compared with the baseline before sVX (pre-sVX)

the gastric motility frequency after sVX (post-sVX) was decreased in the control group 1 and the model group 1 (

P

<

0.001

P

<

0.05). Compared with pre-sVX

the gastric motility amplitude

area under the curve (AUC) and frequency post-sVX of EA at "Zusanli" (ST36) and "Neiguan" (PC6) were decreased in the control group 1 and the model group 1 (

P

<

0.001). Compared with EA at "Neiguan" (PC6) pre-sVX

the gastric motility amplitude and AUC pre-sVX of EA at "Zusanli" (ST36) were increased in the control group 1 and the model group 1 (

P

<

0.001). Compared with the control group 2

the number of activated ChAT neurons in the DMV was decreased in the model group 2 (

P

<

0.001). Compared with the model group 2

the number of activated ChAT neurons in the DMV was increased in the Zusanli group and the Neiguan group (

P

<

0.001

P

<

0.05). Compared with the Neiguan group

the number of activated ChAT neurons in the DMV was increased in the Zusanli group (

P

<

0.01).

Conclusion

2

EA at both "Zusanli" (ST36) and "Neiguan" (PC6) can promote gastric motility in DGP mice

and the effect of "Zusanli" (ST36) is superior to that of "Neiguan" (PC6). Its neural mechanism may be related to the regulation of gastric motility by descending ChAT neurons in the DMV through the vagus nerve.