Quantification of neurological and other contributors to continence in female rats.

Smooth muscle, striated muscle, their central and peripheral innervations and control, and mucosal coaptation contribute to maintenance of continence. We used manual leak point pressure (mLPP) testing and electrical stimulation LPP (eLPP) testing in female rats to quantify the contribution of these factors to urethral resistance, a measure of continence. Abdominal muscles were electrically stimulated to induce leakage for eLPP.

Pelvic floor muscles and the external urethral sphincter have different responses to applied bladder pressure during continence.

Objectives: To determine the functional innervation of the pelvic floor muscles (PFM) and whether there is PFM activity during an external pressure increase to the bladder in female rats.

Methods: Thirty-one female adult virgin Sprague-Dawley rats received an external increase in bladder pressure until urinary leakage was noted while bladder pressure was recorded (leak point pressure [LPP]) under urethane anesthesia. Six of the rats underwent repeat LPP testing after bilateral transection of the levator ani nerve.

Effects of sphincterotomy and pudendal nerve transection on the anal sphincter in a rat model.

Purpose: Our objective was to define anal resting pressure and electromyography of the normal rat anal sphincter and investigate the short-term effects of both mechanical trauma to the anal sphincter muscles and pudendal nerve transection.

Methods: Forty-five virgin female Sprague-Dawley rats were randomly allotted to three groups: controls (n = 21), sphincterotomy (n = 12), and pudendal nerve transection (n = 12). Anal pressure was monitored using a saline-filled balloon connected to a pressure transducer.

Electrophysiological function during voiding after simulated childbirth injuries.

During vaginal delivery dual injuries of the pudendal nerve and the external urethral sphincter (EUS), along with other injuries, are correlated with later development of stress urinary incontinence. It is not known how combinations of these injuries affect neuromuscular recovery of the micturition reflex. We investigated the EUS electromyogram (EMG) and the pudendal nerve motor branch potentials (PNMBP) during voiding 4 days, 3 weeks or 6 weeks after injury; including vaginal distension (VD), pudendal nerve crush (PNC), both PNC and VD (PNC+VD), and pudendal nerve transection (PNT); and in controls.