Biological effects of electrical stimulation on pelvic floor muscle strength and neuropeptide Y expression

Objective: This study aimed to evaluate neuropeptide Y (NPY) expression and pelvic floor muscle strength of stress urinary incontinence (SUI) and diabetes rats before and after ES (electrical stimulation), and to compare the neuromuscular morphology and pathological features. Materials and Methods: Animal models of SUI or diabetes were induced by vaginal balloon dilation, or high-fat high-energy diet plus STZ injection respectively. The strength of pubococcygeal muscles were measured utilizing a biomechanical system, NPY expression was detected by ELSIA assay and western blotting. The histology of pelvic floor muscles was analyzed by H&E staining. Results: Stationary contractility and forced contractility of pelvic floor muscles in rats of SUI or diabetes were significantly increased after ES treatment. The NPY concentration in plasm of SUI or diabetes groups were largely promoted, and increased expression of NPY amount was correlated with enhanced muscle contractility before and after ES treatment. The pubococcygeal muscle morphology of SUI or diabetes animal models has appeared similar myogenic neurogenic performance, which may be good simulated the etiology of pelvic floor dysfunction. Conclusions: The present study has shown ES increases the release of NPY as a neurotransmitter, which reflects the recovery of the damaged nerve to increase the muscle strength. ES may be an ideal physiotherapy for SUI patients in clinical.