Bidirectional regulation of distal colon motility in rats with electroacupuncture of different intensities at "Tianshu" (ST25).
10.13703/j.0255-2930.20240409-k0001
- Author:
Tong LI
1
;
Xiaoyu LIU
1
;
Xiaoyu WANG
1
;
Min LUO
1
;
Zhiyun ZHANG
1
;
Yangshuai SU
1
;
Xianghong JING
1
Author Information
1. Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
- Publication Type:Journal Article
- Keywords:
Point ST25 (Tianshu);
bidirectional regulation;
colonic motility;
electroacupuncture;
enteric nervous system;
functional intestinal diseases
- MeSH:
Animals;
Electroacupuncture;
Male;
Rats;
Colon/innervation*;
Acupuncture Points;
Rats, Sprague-Dawley;
Constipation/physiopathology*;
Gastrointestinal Motility;
Humans;
Diarrhea/physiopathology*
- From:
Chinese Acupuncture & Moxibustion
2025;45(4):460-472
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To observe the distribution characteristics of sensitization areas on the body surface in the rat models with functional constipation and diarrhea, explore the regulatory patterns of electroacupuncture (EA) of different intensities at "Tianshu" (ST25) on distal colon motility, and clarify the roles of the neurons of different subtypes in the enteric nervous system (ENS) displayed in the regulatory effect.
METHODS:Of 90 SD male rats of SPF grade, 15 rats were randomized into a normal group, a constipation group and a diarrhea group, 5 rats in each one. The stool form and fecal water content, as well as the distribution of the Evans blue (EB) extravasation on the body surface after the intravenous injection with EB on the tails were observed. Eighteen rats were randomized into a normal +2 mA group, a normal +4 mA group and a normal + 6 mA group, 6 rats in each one. Using physiological signal acquisition system, the area under the curve and the average amplitude of colon peristalsis were recorded and analyzed, and the immediate effect on distal colon peristalsis observed after EA with different intensities at "Tianshu" (ST25). Thirty rats were randomized into a normal group, a constipation group, a diarrhea group, a constipation +2 mA group, and a diarrhea +6 mA group, 6 rats in each one, so as to observe the cumulative effect on colon motility disorder in the rat models of constipation and diarrhea after EA at "Tianshu" (ST25). Twelve rats were randomized into a constipation +2 mA group and a diarrhea +6 mA group, 6 rats in each one, to observe the immediate effect on colon motility disorder in the rat models of constipation and diarrhea after EA at "Tianshu" (ST25). Fifteen rats were randomly divided into a normal group, a constipation group, a diarrhea group, a constipation +2 mA group, and a diarrhea + 6 mA group, 3 rats in each one. Using the whole-mount staining technique, the expression of vesicular acetylcholine transporter (VAChT)-positive neurons and nitric oxide synthase (nNOS)-positive neurons in ENS was detected. According to the group divisions, the functional constipation models were established by intragastric administration of loperamide hydrochloride (10 mg/kg, once daily, for consecutive 7 days), and the functional diarrhea models were prepared by intragastric administration of folium sennae decoction (10 mL/kg, once daily, for consecutive 2 days). The interventions were delivered with EA of different intensities (the electric current of 2, 4 or 6 mA) at bilateral "Tianshu" (ST25), separately, with the continuous wave and the frequency of 10 Hz used.
RESULTS:Compared with the normal group, the fecal amount was decreased, and the fecal water content was reduced in the rats of the constipation group (P<0.001); and loose stool was presented and the fecal water content increased in rats of the diarrhea group (P<0.001). EB extravasation on the body surface happened in the region from T6 to S2 of the rats in the constipation and diarrhea groups, and it was more concentrated in the lower abdominal and the lower back regions from T10 to L3. Compared with the indexes before EA, in the normal +2 mA group and the normal +4 mA group, the areas under the curve and the average amplitude of the distal colon peristalsis were higher during EA delivery (P<0.01, P<0.05), showing a stimulatory immediate effect; and the post-effect was obtained after EA at 2 mA. Whereas, these two indexes were declined during EA in the rats of the normal +6 mA group (P<0.001), showing an inhibitory immediate effect. After many interventions with EA, when compared with those before EA, the above two indexes rose in the constipation +2 mA group (P<0.05, P<0.01), and they were dropped in the diarrhea +6 mA group (P<0.01, P<0.05). The area under the curve of the colon peristalsis in the constipation +2 mA group was higher than that of the constipation group (P<0.001), and that in the diarrhea +6 mA group was lower compared with that in the diarrhea group (P<0.001). The stimulatory effect of EA on colon motility in the constipation +2 mA group was stronger than that of the normal + 2 mA group (P<0.05), and its inhibitory effect was not different statistically in comparison between the normal +6 mA group and the diarrhea +6 mA group (P>0.05). In ENS of the distal colon, after EA at 2 mA, the proportion of VAChT-positive neurons was higher than that of the activated nNOS-positive neurons (P<0.001); and after EA at 6 mA, the activated nNOS-positive neurons were dominant (P<0.001).
CONCLUSION:In the functional constipation and diarrhea rat models, the sensitization areas on the body surface are centralized in the lower abdominal and the lower back regions of T10 to L3. Electroacupuncture at "Tianshu" (ST25) has a bidirectional regulatory effect on distal colon motility, and this effect is coordinated with the intensity of electroacupuncture, and may be mediated by ENS neurons of different subtypes.
