Bladder underactivity induced by prolonged pudendal afferent activity in cats

Area of Science:

• Urology
• Neuroscience
• Animal Models

Background:

• Underactive bladder (UAB) is a condition characterized by impaired bladder function.
• Nonobstructive urinary retention (NOUR) in Fowler's syndrome may be linked to abnormal afferent activity.
• Developing reliable animal models is crucial for studying UAB and NOUR mechanisms.

Purpose of the Study:

• To investigate the effects of pudendal nerve stimulation (PNS) on reflex bladder activity.
• To establish an animal model of underactive bladder (UAB) using PNS.
• To explore the potential of this model for investigating treatments for Fowler's syndrome.

Main Methods:

• Six anesthetized cats underwent urethral catheterization for bladder pressure monitoring.
• Pudendal nerve stimulation (PNS) was applied using cuff electrodes at varying intensities (2-6 T) and durations.
• Cystometrograms (CMGs) were performed to assess bladder capacity and contractility before and after PNS.
• Repeated, prolonged PNS was administered to induce and characterize UAB.

Main Results:

• Pudendal nerve stimulation (PNS) during CMGs significantly increased bladder capacity.
• Higher intensity PNS (4 T) reduced bladder contraction amplitude, duration, and area.
• Repeated 30-minute PNS (cumulative 3-8 hours) induced UAB with significantly increased capacity and reduced contraction amplitude.
• The induced UAB persisted for over 1.5-2 hours post-stimulation.

Conclusions:

• Pudendal nerve stimulation can effectively induce a state of underactive bladder in a feline model.
• This feline model of UAB may elucidate the mechanisms underlying nonobstructive urinary retention in Fowler's syndrome.
• The findings support the hypothesis that abnormal afferent signals contribute to NOUR and suggest potential therapeutic targets.