Low Intensity Pulsed Ultrasound Influences the Myogenic Differentiation of Muscle Satellite Cells in a Stress Urinary Incontinence Rat Model.

Abstract

OBJECTIVE: To investigate the therapeutic effect of low intensity pulsed ultrasound (LIPUS) in a stress urinary incontinence (SUI) rat model and its influence on myogenic satellite cells. METHODS: Fifty Sprague-Dawley rats underwent vaginal distension and bilateral ovariectomy mimicking partum injury and menopause to construct SUI models, which were further randomized into 100 mW/cmLIPUS, 200 mW/cmLIPUS, 300 mW/cmLIPUS, and none-treatment control subgroups with 10 rats per subgroup. Ten rats served as mock operation control. Leak point pressure and bladder capacity were recorded 1 week after LIPUS treatment. Immunofluorescence staining and Western blot were performed to examine histological changes, myodifferentiation, and signaling pathway. RESULTS: Here,we found the leak point pressure and bladder capacity were restored in 200 mW/cmLIPUS and 300 mW/cmLIPUS groups, but not in 100 mW/cmLIPUS group. More robust striated muscle regeneration was observed in 200 mW/cmLIPUS group comparing with the SUI none-treatment group. Moreover, we found LIPUS activated the myodifferentiation of muscle satellite cells, which is correlated to p38 phosphorylation level. CONCLUSION: LIPUS restored the leak point pressure and bladder capacity, and activated satellite cell myodifferentiation in SUI rat model.