A Method for Recording Urethral Pressure Profiles in Female Rats

Abstract

AimsUrethral pressure profile (UPP) and leak-point pressure (LPP) measurements as well as external urethral sphincter (EUS) electromyography (EMG) and videourodynamic analyses are the primary methods for evaluating urethral function in humans. However, UPP recording in female rats, a widely used animal model, is challenging due to their small body sizes. This study reports a novel method for recording UPP in female rats.Materials and MethodsSeventeen anesthetized female rats were studied. LPP data for 14 rats were included. The other 3 rats were excluded because of death or abnormal urogenital organs. UPP curves were recorded using a modified water-perfusion catheter system, with the lateral hole facing the 3-, 6-, 9-, and 12-o’clock positions in a randomized sequence. LPP, functional urethral length (FUL) and maximum urethral closure pressure (MUCP) were analyzed.ResultsThe mean LPP was 64.39 ± 20.29 cm H2O. The mean FUL and MUCP values at the 3-, 6-, 9-, and 12-o’clock positions were 12.90 ± 1.20, 16.70 ± 1.95, 13.90 ± 2.42, and 11.60 ± 0.97 mm, respectively, and 38.70 ± 11.85, 33.90 ± 11.82, 37.40 ± 11.95, and 71.90 ± 23.01 cm H2O, respectively. The FUL at the 6-o’clock position and MUCP at the 12-o’clock position were significantly greater than those at the other 3 positions. The FUL and MUCP of repeated UPP recordings were not significantly different than those of the first recordings.ConclusionsUPP recording using a modified method based on a water-perfusion catheter system is feasible and replicable in female rats. It produces UPP curves that sensitively and appreciably reflect detailed pressure changes at different points within the urethra and thus provides opportunity to evaluate urethral structures, especially the urethral sphincter, in detail. These results may enhance the utility of female rat models in research of urinary sphincter mechanisms.

In vivo molecular engineering of the urethra for treatment of stress incontinence using novel biomimetic proteoglycans

“…Pressure measurements were more inconsistent 3 cm away distal to the injection site (close to the distal urethra). An in vivo study by Xu et al collected urethra pressure profiles with female rats at different locations of the urethra. The data revealed higher pressure inconsistencies near distal urethra as compared to the proximal urethra.…”

Regional Structural and Functional Specializations in the Urethra of the Female Rat: Evidence for Complex Physiological Control Systems

“…In an attempt to determine whether this complex pattern of structural elements could be correlated with any functional characteristics, measurements of urethral wall compliance were made along its length (see Xu et al, and legend Fig. ).…”

“…The approach used was adapted from the method described by Xu et al, () to measure urethral pressure profiles. However, it is argued here that the method actually measures the compliance of the wall rather than the intrinsic pressure generated within the wall.…”

An optimized transurethral catheterization cystometry in mice and comparison with classic suprapubic catheterization cystometry

“…Besides, compared with SCC, the method of optimized transurethral cystometry is easy to use by researchers. In addition, no record of UPP measurement in mice was found and only one early study showed a similar method for the UPP record in female rats . We present a novel method for recording UPP in female mice.…”

“…Thus, we propose that the UPP measurement could be used to measure the establishment of mice partial bladder outlet obstruction (pBOO) model. Early study proposed a method of testing the UPP in rats, and it is still challenging to record UPP in mice.…”