Low-intensity extracorporeal shockwave therapy ameliorates diabetic underactive bladder in streptozotocin-induced diabetic rats.

OBJECTIVES: To evaluate the therapeutic effect of once-weekly low-intensity extracorporeal shock wave therapy (Li-ESWT) on underactive bladder (UAB) in the streptozotocin (STZ)-induced diabetic rat model. MATERIALS AND METHODS: In all, 36 female Sprague-Dawley rats were divided into three groups: normal control (NC), diabetes mellitus control (DMC), and DM with Li-ESWT (DM Li-ESWT). The two DM groups received an intraperitoneal 60 mg/kg STZ injection to induce DM. The Li-ESWT was applied toward the pelvis of the rats starting 4 weeks after STZ administration and lasting for 4 weeks. The Li-ESWT was given once weekly, with an energy flux density of 0.02 mJ/mm2 at 3 Hz for 400 pulses. All rats underwent conscious cystometry, leak-point pressure (LPP) assessment, ex vivo organ-bath study, histology, immunofluorescence, and Western Blot analysis. RESULTS: Conscious cystometry revealed voiding dysfunction in the DMC group, whereas the DM Li-ESWT group showed significantly improved voiding function, reflected in a reduced post-void residual urine volume and increased LPP compared to the DMC group. Ex vivo organ-bath studies showed that Li-ESWT enhanced muscle contractile activity of the bladder and urethra during electrical-field stimulation and drug stimulation. Histologically, Li-ESWT significantly restored bladder morphology, reflected by a reduction in the intravesical lumen area and increased muscle proportion of the bladder wall. Western Blot analysis showed higher smooth muscle actin expression in the bladder wall in the DM Li-ESWT group compared to the DMC group. Immunofluorescence showed decreased nerve-ending distribution, and destroyed and shortened nerve fibres in the DMC group, and recovery of neuronal integrity and innervation in the DM Li-ESWT group. CONCLUSIONS: In conclusion, Li-ESWT ameliorated UAB and urinary incontinence in the diabetic UAB rat model. The improvement appears to be the result of restoration of bladder and urethral structure and function by Li-ESWT. Li-ESWT is non-invasive and may become a better alternative therapy for UAB. Further investigations are warranted.

The effect of low-intensity extracorporeal shockwave therapy in an obesity-associated erectile dysfunction rat model.

OBJECTIVES: To investigate the feasibility of the Zucker fatty (ZF) rat as a model for research in to obesity-associated erectile dysfunction (OAED) and to determine the effect of low-intensity extracorporeal shockwave therapy (Li-ESWT) on penile tissue and function in these rats. MATERIALS AND METHODS: Eight new-born male Zucker lean (ZL group) rats (ZUC-Leprfa 186) and 16 new-born male ZF rats (ZUC-Leprfa 185) were injected with 5-ethynyl-2'-deoxyuridine (EdU) at birth to identify and monitor endogenous stem cells. Insulin tolerance testing was performed at 10 weeks of age. Beginning at 12 weeks of age, eight ZF rats were kept as controls, and the remaining eight ZF rats were treated with Li-ESWT (0.02 mJ/mm2 , 3 Hz, 500 pulses; ZF + SW group) twice a week for 4 weeks. Following a 1-week washout period, erectile function was evaluated by measuring intracavernosal pressure (ICP) and mean arterial pressure (MAP). Penile tissues were then harvested for histological study to assess smooth muscle/collagen content and endothelium content in the corpora cavernosum. LipidTOX™ staining was used to evaluate lipid accumulation. EdU, as a marker of cell activation, and phosphorylated histone 3 (H3P), as a marker of cell mitosis, were also assessed. RESULTS: The ICP/MAP indicated that erectile function was severely impaired in the ZF group as compared with the ZL group. In the ZF + SW group, erectile function was significantly improved (P < 0.05). Muscle atrophy was seen in the ZF group, while Li-ESWT increased the muscle content in ZF + SW group. Moreover, the penile endothelium was damaged in the ZF group, and Li-ESWT enhanced the regeneration of endothelial cells (P < 0.01) in the ZF + SW group. Lipid accumulation was seen in the penile tissue of ZF rats. Li-ESWT significantly reduced both the amount and the distribution pattern of LipidTOX, suggesting decreased overall lipid infiltration. Furthermore, Li-ESWT increased EdU-positive cells and markedly enhanced the phosphorylation level of H3P at Ser-10 in the ZF + SW group. Most H3P-positive cells were located within smooth muscle cells, with some located in the endothelium suggesting that these tissues are the reservoirs of penile stem/progenitor cells. CONCLUSION: ZF rats can serve as an animal model in which to study OAED. This study reveals that obesity impairs erectile function by causing smooth muscle atrophy, endothelial dysfunction, and lipid accumulation in the corpus cavernosum. Li-ESWT restored penile haemodynamic parameters in the ZF rats by restoring smooth muscle and endothelium content and reducing lipid accumulation. The underlying mechanism of Li-ESWT appears to be activation of stem/progenitor cells, which prompts cellular proliferation and accelerates penile tissue regeneration. Our findings are of interest, not just as a validation of this emerging treatment for erectile dysfunction, but also as a novel and potentially significant method to modulate endogenous stem/progenitor cells in other disease processes.

In Situ Activation and Preservation of Penile Progenitor Cells Using Icariside II in an Obesity-Associated Erectile Dysfunction Rat Model.

Obesity-associated erectile dysfunction (ED) involves pathologic change that may be related to deficit of the penile endogenous stem/progenitor cells. Therefore, an in-depth study of the penile stem/progenitor cells in the pathogenesis of ED is warranted. For this study, eight Zucker Lean (ZUC-Leprfa 186; ZL group) and 16 Zucker Fatty (ZUC-Leprfa 185; ZF) male rats received an intraperitoneal injection of 5-ethynyl-2-deoxyuridine (EdU) to track endogenous stem cells. Twelve weeks later, the ZF rats were randomized to gavage feeding with 1.5 mg/kg/day of icariside II (ZF + ICA II group) or the solvent (ZF group). Treatment lasted 4 weeks and was followed by a 1-week washout period. ZF rats had impaired erectile function with related pathologic changes compared with ZL rats. ICA II treatment restored erectile function and prevented smooth muscle atrophy, endothelial dysfunction, and lipid accumulation compared with no treatment. EdU label-retaining cell levels were higher in the ZF + ICA II group compared with the ZF group. Histone 3 phosphorylation at Ser 10, a specific mitotic cell marker, was additionally used to identify dividing cells. ICA II activated more penile stem cells to proliferate in ZF rats compared with ZL rats. These results suggest that ZF rats can be used as a model for obesity-associated ED and that ICA II improves erectile function and pathologic changes through endogenous progenitor cell preservation and proliferation.