Diabetic urethropathy compounds the effects of diabetic cystopathy.

Published

Journal Article

PURPOSE: The effects of short-term and long-term diabetes mellitus on urethral function were investigated to determine the contribution of urethral dysfunction to diabetes mellitus voiding dysfunction. MATERIALS AND METHODS: Isovolumetric bladder pressure, urethral perfusion pressure and external urethral sphincter electromyography were measured in urethane anesthetized, female Sprague-Dawley rats (Charles River Laboratories, Wilmington, Massachusetts) 5 or 10 weeks after streptozotocin induced diabetes mellitus. Urethral responses to serial administration of the skeletal muscle blocker alpha-bungarotoxin, the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine and the alpha-adrenergic agonist L-phenylephrine were determined in diabetes mellitus and age matched controls. RESULTS: Peak bladder pressures and contraction amplitudes were significantly decreased in diabetes mellitus rats. Detrusor-sphincter dyssynergia occurred in approximately 30% of diabetes mellitus rats but never in controls. Alpha-Bungarotoxin caused a greater decrease in baseline urethral perfusion pressure in diabetes mellitus rats than in controls (approximately 40% vs approximately 15%). Bladder contraction associated urethral smooth muscle relaxation amplitudes were significantly less in diabetes mellitus rats than in controls. N(omega)-nitro-L-arginine significantly suppressed urethral relaxation in controls but not in diabetes mellitus rats. L-phenylephrine significantly increased baseline urethral perfusion pressure in diabetes mellitus rats but not in controls. The unassociated conditions of insensitivity to N-nitro-L-arginine and hypersensitivity to L-phenylephrine were more common in 10-week diabetes mellitus rats than in control rats. CONCLUSIONS: Diabetes mellitus induced urethropathy is characterized by external urethral sphincter dysfunction, decreased urethral smooth muscle relaxation and nitric oxide responsiveness, and increased urethral smooth muscle responsiveness to alpha(1)-adrenergic agonists. These changes increase outlet resistance and, thereby, decrease voiding efficiency. This exacerbates voiding dysfunction, creating a vicious cycle of progressive lower urinary tract damage and dysfunction. Early intervention targeting outlet resistance may be indicated.

Full Text

Duke Authors

Cited Authors

  • Yang, Z; Dolber, PC; Fraser, MO

Published Date

  • November 2007

Published In

Volume / Issue

  • 178 / 5

Start / End Page

  • 2213 - 2219

PubMed ID

  • 17870107

Pubmed Central ID

  • 17870107

International Standard Serial Number (ISSN)

  • 0022-5347

Digital Object Identifier (DOI)

  • 10.1016/j.juro.2007.06.042

Language

  • eng

Conference Location

  • United States