Abstract
We investigated the characteristics of bladder mechanosensitive single-unit afferent activities (SAAs) in rats with a bladder outlet obstruction (BOO) and their relationship with bladder microcontractions. Male Wistar rats were divided into Sham and BOO groups. Four or 10 days after the surgery, rats were anesthetized with urethane. The SAAs of Aδ- or C-fibers from the L6 dorsal roots were recorded during bladder filling. The BOO group showed a higher number of microcontractions and lower SAAs of Aδ-fibers compared with those of the Sham group. These findings were significant at day 10 post-operatively. In contrast, SAAs of C-fibers were not significantly different between the groups at either day 4 or 10. In the BOO group at day 10, the SAAs of both Aδ- and C-fibers at the “ascending” phase of microcontractions were significantly higher than those at the other phases (descending or stationary), and a similar tendency was also observed at day 4. Taken together, during bladder filling, the bladder mechanosensitive SAAs of Aδ-fibers were attenuated, but SAAs of both Aδ- and C-fibers were intermittently enhanced by propagation of microcontractions.
Highlights
Detrusor overactivity (DO) has been defined as “a urodynamic observation characterized by involuntary detrusor contractions during the filling phase which can be spontaneous or provoked”[1], and is commonly associated with the overactive bladder syndrome (OAB)[2]
We further investigated CMG parameters at day 4, and found that the number and amplitude of non-voiding contractions (NVCs) in the bladder outlet obstruction (BOO) rats were significantly higher than in the Sham rats, whereas there were no significant differences between the groups in the other parameters (Fig. 1 upper traces, Table 1)
When the parameters were reanalyzed by the same methods used in the present study (Supplemental table) we found similar changes in the number and amplitude of NVCs as at day 4
Summary
Detrusor overactivity (DO) has been defined as “a urodynamic observation characterized by involuntary detrusor contractions during the filling phase which can be spontaneous or provoked”[1], and is commonly associated with the overactive bladder syndrome (OAB)[2]. In women with OAB, micromotions were enhanced and concomitantly observed with urinary urgency during filling cystometry (CMG)[6]. These previous studies suggest that the microcontractions or micromotions may partly contribute to the development of urgency in humans with OAB. This has been discussed in a recent review[7]. In the present study, we investigated the characteristics of bladder mechanosensitive single-unit afferent activities (SAAs) in male rats with BOO, and their relationship with bladder microcontractions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
