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

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 par- tum injury and menopause to construct SUI models, which were further randomized into 100 mW/cm(2) LIPUS, 200 mW/cm(2) LIPUS, 300 mW/cm(2) LIPUS, and none-treatment control sub-groups 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/cm(2) LIPUS and 300 mW/cm(2) LIPUS groups, but not in 100 mW/cm(2) LIPUS group. More robust striated muscle regeneration was observed in 200 mW/cm(2) LIPUS 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. (C) 2018 Published by Elsevier Inc.