Electroacupuncture Improves Anorectal Function in Neurogenic Fecal Incontinence Rats, Related to Reversing Anal Sphincter Atrophy and Enhancing Muscle Satellite Cell Activity.

Neurogenic fecal incontinence (NFI) is a disorder of anal dysfunction caused by nerve damage. Electroacupuncture (EA), grounded in Traditional Chinese Medicine (TCM) theory, has demonstrated efficacy in treating various degenerative disorders and is extensively utilized in the clinical management of neurogenic FI. The proliferation and differentiation of muscle satellite cells (SCs) are crucial in the onset and progression of this condition. However, the specific mechanism of electroacupuncture in treating neurogenic fecal incontinence is not yet clear. This study sought to determine whether EA could enhance anal function in rats with neurogenic FI and to elucidate its mechanisms of action. We observed the effect of electroacupuncture on anorectal function in rats with neurogenic fecal incontinence and its mechanism of action. The morphology and arrangement of anal sphincter muscle fibers were altered due to pudendal nerve injury. The expression levels of two atrophy markers, Muscle-specific RING finger protein 1 (MuRF-1) and Atrogin-1, were elevated in the anal sphincter muscles, and shifts were seen from slow-twitch to fast-twitch muscle fibers. Post EA treatment, the expression levels of atrophy markers were reversed; the proportion of slow-twitch fibers in the muscles increased, and the expressions of Pax3 and Myod1, which had decreased 3 weeks post-injury, significantly increased and gradually normalized. These results indicate that EA effectively ameliorates anal function in rats with neurogenic FI, primarily through mechanisms that involve the activation of muscle SCs.