Objective

2

To explore the peripheral neural mechanism underlying representation along the distribution of stomach meridian induced by intestinal inflammatory reaction using diarrhea predominant-irritable bowel syndrome (IBS-D) mice.

Methods

2

Among 62 healthy male C57BL/6 mice of clean grade

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

6 mice in each group

additionally

12 mice were randomly selected and divided into a Tianshu group

a Liangqiu group and a Zusanli group

4 mice in each group. In the model group

citrobacter was administered orally to establish IBS-D model. In the control group and the model group

the visceral pain threshold was observed using fecal colorectal distension (fCRD) induced electromyography of external oblique muscle

the positive cell number of neutrophil in the colonic muscularis was detected by myeloperoxidase (MPO) staining

the number

location and distribution rule of Evans blue (EB) extravasation points were observed by injection of EB staining solution into the tail vein. In the Tianshu group

the Liangqiu group and the Zusanli group

fluorescent dye Dil was injected at bilateral "Tianshu" (ST25)

"Liangqiu" (ST34) and "Zusanli" (ST36) respectively

to observe the dye-positive cell number in different dorsal root ganglion (DRG) segments. In the control group and the model group

the activation of satellite glial cells (SGCs) in different DRG segments was observed by immunofluorescence.

Results

2

Compared with the control group

in the model group

the area under curve of electromyography of external oblique muscle was increased at fCRD of 25

50 and 75 μL distilled water (

P

<

0.001

P

<

0.01); the MPO-positive cell number of neutrophil in the colonic muscularis was increased (

P

<

0.01). Few EB extravasation points could be found in the control group

while there were much more EB extravasation points observed in the model group

which was specially distribution in the area of stomach meridian

from "Huaroumen" (ST24) to "Zusanli" (ST36)

as well as the surface area dominated by L

2

-L

5

segment of the spinal cord. The Dil-positive cells were mainly exhibited in the DRG of T

11

L

5

and L

4

segments in the Tianshu group

the Liangqiu group and the Zusanli group

respectively. Compared with the control group

the ratio of glial fibrillary acidic protein (GFAP)/glutamine synthetase (GS) co-expression was increased in the DRG of T

11

L

4

and L

5

segments in the model group (

P

<

0.05

P

<

0.01).

Conclusion

2

The activation of SGCs within DRG of T

11

L

4

and L

5

segments may relate closely to the occurrence of the representation along the stomach meridian distribution in IBS-D mice.