Functional and Immunofluorescence Evaluations of Vascular and Neural Integrities in Urinary Bladder of Streptozotocin-Induced Diabetic Mice

초록

Purpose: To assess functional and structural changes in vascular and neural structures associated with diabetic bladder dys-function (DBD) in the bladders of streptozotocin (STZ)-induced diabetic mice. Methods: Eight-week-old C57BL/6 mice were injected with STZ at 50 mg/kg daily for 5 consecutive days. Catheters were in-serted 12 weeks later, and 5 days after catheter placement bladder functions were assessed by conscious cystometry. Neurovas-cular and extracellular matrix marker changes in harvested urinary bladders were investigated by immunofluorescent stain-ing. Body weights and fasting and postprandial blood glucose levels were measured 12 weeks after STZ injection.Results: STZ-induced diabetic mice had significantly lower body weights and significantly higher blood glucose levels. Assess-ment of bladder function in STZ-induced diabetic mice revealed a nearly 3-fold increase in bladder capacity and intercontrac-tile interval compared to controls. However, basal pressure, maximal bladder pressure, and threshold pressure were not signifi-cantly different. Morphological and structural analysis showed that STZ-induced diabetic mice had significantly reduced mi-crovascular density in lamina propria (33% of the nondiabetic control values), and severely decreased nerve contents in the detrusor region (42% of the nondiabetic control values).Conclusions: STZ-induced diabetic mice exhibit functional and structural derangements in urinary bladder. The present study provides a foundation and describes a useful means of evaluating the efficacies of therapeutic targets and exploring the detailed mechanism of DBD.

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