Introduction: Past research has demonstrated that the urethral tonus is mainly under sympathetic control. Since 5 years, a beta 3-adrenoceptor (ADRB3) agonist is available in the treatment of overactive bladder syndrome. The presence of ADRB3 within the human urethra has not been demonstrated to date. Presence of ADRB3 in the urethra could influence urethral tonus. The aim of this study is to investigate the presence of ADRB3 in the human female urethra. Material and Methods: We performed anatomical studies in five female specimens. Three specimens were obtained from the body donation program, two from female patients with muscle-invasive bladder cancer, where radical resection of bladder and urethra was performed. The urethra up till the bladder neck was separated from the rest of the bladder and freshly obtained for this study. For demonstrating ADRB3 expression, we used rabbit polyclonal antihuman ADRB3 LS-A4198. Results: Expression of ADBR3 was demonstrated in the epithelial layer of all urethral parts, except at the level of the meatus. The level of ADRB3 expression was highest in the mid urethra. There was no direct contact between ADRB3 and nerve tissue. ADRB3 expression was also demonstrated in the stratified muscle layer at the level of the external urethral sphincter. Conclusions: This is the first study to demonstrate the expression of ADRB3 in the human female urethra. There is an absence of a direct connection between ADRB3 and nerve tissue.

Aims During filling cystometry, urethral pressure variations (UPV) can be observed. The clinical relevance and a clear definition of this phenomenon are still a matter of debate. For further research and definition of UPV, it is important to determine how this condition can best be demonstrated. The purpose of this study is to compare continuous urethral pressure measurements with a single urethral‐sensor catheter and a triple urethral‐sensor catheter in demonstrating UPV. Methods Seventy‐five adult female patients requiring urodynamic investigation enrolled in this prospective study. All patients underwent two series of filling and voiding cystometry. One series was performed with a dual‐air balloon sensor urodynamic catheter, the other series with a triple urethral‐sensor catheter. UPV were defined as urethral pressure drop exceeding 30 cmH2O. Results The prevalence of UPV was 37.3% (28 out of 75 patients), more common than detrusor overactivity. The triple urethral‐sensor catheter was more sensitive than the single urethral‐sensor catheter: In eight patients UPV were demonstrated with both catheters and in 18 patients only in the measurement with the triple urethral‐sensor catheter. This difference in detection was significant (P < .001). Conclusion There is an additional value in measurement with the triple urethral‐sensor catheter for demonstration of UPV during filling cystometry. Currently, continuous measurement of urethral pressure during filling cystometry and UPV is not defined within International Continence Society terminology. The single urethral‐sensor catheter is useful for a start, however, it demonstrates less than half of all UPV