The aim of the present study was to use a model of simulated human childbirth in rats to determine the damage to genitourinary structures and behavioral signs of urinary dysfunction induced by VD in female rats. In Experiment 1, the length of the genitourinary tract and the nerves associated with it were measured immediately after simulated human delivery induced by vaginal distension (VD) or sham (SH) procedure. Electroneurograms of the dorsal nerve of the clitoris (DNC) was also recorded. In Experiment 2, histological characteristics of the bladder and major pelvic ganglion (MPG) of VD and SH rats were evaluated. In Experiment 3, urinary parameters were determined in conscious animals, during 6 h of dark and 6 h of light, before and three days after VD or SH procedure. VD significantly increased distal vagina width (p<0.001) and length of the motor branch of the sacral plexus (p<0.05), the DNC (p<0.05) and vesical nerves (p<0.01), and decreased DNC frequency and amplitude of firing. VD occluded the pelvic urethra inducing urinary retention, hematomas in the bladder and thinness of the epithelial (p<0.05) and detrusor (p<0.01) layers of the bladder. MPG parameters were not modified after VD. Rats dripped urine in unusual places to void, without the stereotyped behavior of micturition after VD. The neuroanatomical injuries after VD occur alongside behavioral signs of urinary incontinence as determined by a new behavioral tool for assessing micturition in conscious animals.
- Dorsal nerve of the clitoris
- Major Pelvic Ganglion
- Copyright © 2015, American Journal of Physiology - Renal Physiology