Urodynamic evaluation and electrical and pharmacologic neurostimulation. The rat model

Area of Science:

• Urology
• Neuroscience
• Physiology

Background:

• Understanding detrusor/sphincter interrelationships is crucial for studying lower urinary tract function.
• Existing models may lack the precision to fully elucidate these complex interactions.

Purpose of the Study:

• To introduce and validate a novel rat model for simultaneous bladder and urethral sphincter activity recording.
• To investigate the effects of different anesthetics on urodynamic parameters and micturition cycles.
• To establish a model for studying neuropharmacological and electrostimulatory effects on urodynamics.

Main Methods:

• Simultaneous recording of bladder pressure and external urethral sphincter electromyography in rats.
• Utilizing a polyethylene tube for intravesical saline perfusion and an electromyography needle electrode.
• Investigating urodynamic changes under urethane, methoxyflurane (Metofane), and thiobutabarbital sodium (Inactin) anesthesia.

Main Results:

• High-frequency oscillations in bladder pressure during micturition were observed only with urethane or Metofane anesthesia.
• The external urethral sphincter's striated muscle activity was identified as the driving force for urine expulsion.
• Inactin anesthesia, especially with low perfusion, suppressed bladder/sphincter activity and abolished micturition cycles.

Conclusions:

• The developed rat model enables precise measurement of bladder and sphincter function and their interrelationship.
• Anesthetic choice significantly impacts urodynamic parameters and micturition, with urethane/Metofane supporting physiological studies and Inactin suitable for neuropharmacological evaluations.
• This model is valuable for investigating responses to nerve stimulation and pharmacological agents at the spinal cord level.