Chronic Sacral Nerve Stimulation Inhibits Visceral Hypersensitivity in Diarrhea-Predominant Irritable Bowel Syndrome Rats Model

Xiaojuan Guo; Changsheng Lei; Hanwei Liang; Jiaxu An; Yanbin Fang; Xiaolu Zhang; Zhiyan Wang; Chunhua Hu; Xuan Jiang

doi:10.1016/j.neurom.2023.08.010

Chronic Sacral Nerve Stimulation Inhibits Visceral Hypersensitivity in Diarrhea-Predominant Irritable Bowel Syndrome Rats Model

Neuromodulation. 2024 Feb;27(2):295-301. doi: 10.1016/j.neurom.2023.08.010. Epub 2023 Nov 4.

Authors

Xiaojuan Guo¹, Changsheng Lei², Hanwei Liang¹, Jiaxu An¹, Yanbin Fang¹, Xiaolu Zhang¹, Zhiyan Wang³, Chunhua Hu², Xuan Jiang⁴

Affiliations

¹ Department of Gastroenterology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China.
² National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing, China.
³ CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Department of Psychology, University of Chinese Academy of Science, Beijing, China.
⁴ Department of Gastroenterology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China. Electronic address: jxa01998@btch.edu.cn.

PMID: 37930296
DOI: 10.1016/j.neurom.2023.08.010

Abstract

Objective: Sacral nerve stimulation (SNS) is emerging as a novel treatment for irritable bowel syndrome (IBS). However, its effects are limited, and the underlying mechanisms remain largely unknown.

Materials and methods: In this study, rats were divided into three groups (n = 12 rats per group): 1) the SNS group; 2) the sham SNS group (the sham group for short); and 3) the control group. The SNS and sham groups were exposed to chronic and acute stress to establish an IBS model. Electrode implantation surgery was performed in rats with the IBS model. The SNS group received electrical stimulation for 30 minutes every day for seven days. Abdominal withdrawal reflex (AWR) was used to evaluate the effect of SNS on visceral sensitivity in diarrhea-predominant IBS (IBS-D) rats. The frequency domain of heart rate variability (HRV) was analyzed to assess the effect of SNS on regulating the autonomic function. The expression of transient receptor potential vanilloid 1 (TRPV1) in the colon, spinal cord, and hippocampus was detected by immunohistochemistry to explore the mechanism of SNS in IBS-D rats.

Results: Compared with the sham group, AWR scores were significantly decreased under different gas volumes of stimulation of 0.4, 0.6, and 0.8 ml for rectal distention in the SNS group (all p < 0.05). However, there was no significant difference <1.0 ml between the two groups (p > 0.05). Compared with the sham group, the frequency domain indexes of HRV were significantly altered. Normalized low-frequency power and low frequency-to-high frequency ratio were significantly decreased, and normalized high-frequency power was significantly increased in the SNS group (all p < 0.05). Moreover, the expression of TRPV1 in the spinal cord and colon in the SNS group was significantly decreased compared with the sham group (both p < 0.05). These results suggested that chronic SNS not only improved the visceral sensitivity and autonomic dysfunction but also decreased the expression of TRPV1 in the spinal cord-gut tissue in IBS-D rats.

Conclusion: Chronic SNS was found to have an inhibitory effect on visceral hypersensitivity in IBS-D rats, providing experimental evidence for its potential clinical application in IBS.

Keywords: Heart rate variability; irritable bowel syndrome; sacral nerve stimulation; transient receptor potential vanilloid 1; visceral hypersensitivity.

MeSH terms

Animals
Diarrhea
Irritable Bowel Syndrome* / therapy
Rats
Rats, Sprague-Dawley
Spinal Cord