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Soo Hwan Park, Long Hu Jin, Yong Hyun Kwon, Sang Min Yoon, Ji Kan Ryu, Tack Lee
Abstract
Purpose
Partial bladder outlet obstruction (PBOO) in rats leads to changes in bladder function, such as obstruction and detrusor overactivity (DO). The aim of our study was to observe factors essential for the objective descriptions of PBOO rats as an overactive bladder model as well as an obstruction model under awake cystometry. We also aimed to investigate the urodynamic effects of PBOO objectively in view of DO-related parameters as well as conventional pressure and volume-related parameters.
Materials and Methods
PBOO was produced in 10 female Sprague-Dawley rats by ligating the proximal urethra over a 0.9 mm metal rod; 10 sham-operated rats were used as controls. Intravesical pressure (IVP) was recorded via an open catheter in the bladder, and intraabdominal pressure (IAP) via an intraabdominal balloon catheter. Continuous cystometry was performed 2 weeks after the PBOO procedure. Conventional and newly developed DO-related urodynamic parameters were investigated.
Results
PBOO led to a significant increase in bladder weight. Three rats showed the picture of decompensated bladder and were excluded from the analysis. The obstructed group showed some increased pressure- and volume-related parameters. They showed a DO frequency of 1.5±0.3/min, but the sham group did not.
Conclusions
Our results showed that bladder decompensation can happen after PBOO, and we need to describe those exclusions accurately in reports. In conscious PBOO rats, simultaneous registration of IAP and IVP is needed for accurate investigations of DO, because PBOO can lead to DO as well as bladder hypertrophy.
Figures and Tables
Fig. 1
Representative tracings of rats of sham or obstructed, decompensated bladder. (A) Sham group. (B) Obstructed group. (C) Decompensated group by obstruction. The arrow indicates the nonvoiding contraction during the filling phase. The black arrow head indicates straining voiding without detrusor contraction, which results in urinary incontinence.
Fig. 2
(A) Cystometrogram showing detrusor overactivity (DO) and abdominal straining (AS) with simultaneous registrations of intravesical pressures (IVPs) and intra-abdominal pressures (APs). (B) AS was defined as the IVP rises with a simultaneous rise in AP. (C) DO was defined as the IVP rises without a simultaneous rise in AP.
Table 1
Pressure & volume parameters in awake rats subjected to sham-operation or partial bladder outlet obstructed (PBOO)
BP: basal pressure, TP: threshold pressure, MP: micturition pressure, BC: bladder capacity, MV: micturition volume, RV: residual volume, MI: micturition interval, IVP: intra-vesical pressure, DP: detrusor pressure. Results are expressed as mean±standard error of the mean. a: p<0.01 (paired student's t-test), versus IVP: b: p<0.05, c: p<0.01 (unpaired Student's t-test), versus sham
References
1. Macfarlane GJ, Sagnier PP, Richard F, Teillac P, Botto H, Boyle P. Determinants of treatment-seeking behaviour for urinary symptoms in older men. Br J Urol. 1995. 76:714–718.
2. Knutson T, Edlund C, Fall M, Dahlstrand C. BPH with coexisting overactive bladder dysfunction-an everyday urological dilemma. Neurourol Urodyn. 2001. 20:237–247.
3. Im JG, Kim JC, Hwang TK. The urodynamic findings of male patients with LUTS and the effects of the pre-operative parameters on the outcome of transurethral resection of the prostate. Korean J Urol. 2005. 46:1256–1261.
4. de Groat WC. A neurologic basis for the overactive bladder. Urology. 1997. 50(6A):Suppl. 36–52.
5. Berggren T, Uvelius B. Cystometrical evaluation of acute and chronic overdistension in the rat urinary bladder. Urol Res. 1998. 26:325–330.
6. Mostwin JL, Karim OM, van Koeveringe G, Brooks EL. The guinea pig as a model of gradual urethral obstruction. J Urol. 1991. 145:854–858.
7. Lee SD, Akbal C, Miseeri R, Jung C, Rink R, Kaefer M. Collagen prolyl 4-hydroxylase is up-regulated in an acute bladder outlet obstruction. J Pediatr Urol. 2006. 2:225–232.
8. Rohrmann D, Zderic SA, Duckett JW Jr, Levin RM, Damaser MS. Compliance of the obstructed fetal rabbit bladder. Neurourol Urodyn. 1997. 16:179–189.
9. Malkowicz SB, Wein AJ, Elbadawi A, Van Arsdalen K, Ruggieri MR, Levin RM. Acute biochemical and functional alterations in the partially obstructed rabbit urinary bladder. J Urol. 1986. 136:1324–1329.
10. Kato K, Wein AJ, Radzinski C, Longhurst PA, McGuire EJ, Miller LF, et al. Short term functional effects of bladder outlet obstruction in the cat. J Urol. 1990. 143:1020–1025.
11. Mirone V, Imbimbo C, Longo N, Fusco F. The detrusor muscle: an innocent victim of bladder oulet obstruction. Eur Urol. 2007. 51:57–66.
12. Steers WD, De Groat WC. Effect of bladder outlet obstruction on micturition reflex pathways in the rat. J Urol. 1988. 140:864–871.
13. Levin RM. Genetic and cellular characteristics of bladder outlet obstruction. Urol Clin North Am. 1995. 22:263–283.
14. Lluel P, Duquenne C, Martin D. Experimental bladder instability following bladder outlet obstruction in the female rat. J Urol. 1998. 160:2253–2257.
15. Schafer W, Abrams P, Liao L, Mattiasson A, Pesce F, Spangberg A, et al. Good urodynamic practices: uroflowmetry, filling cystometry, and pressure-flow studies. Neurourol Urodyn. 2002. 21:261–274.
16. Brading AF. A myogenic basis for the overactive bladder. Urology. 1997. 50:57–67.
17. Elbadawi A, Yalla SV, Resnick NM. Structural basis of geriatric voiding dysfunction. IV. Bladder outlet obstruction. J Urol. 1993. 150:1681–1695.
18. Lagou M, Drake MJ, Gillespie JI. Volume-induced effects on the isolated bladder: a possible local reflex. BJU Int. 2004. 94:1356–1365.
19. Lee T, Andersson KE, Streng T, Hedlund P. Simultaneous registration of intraabdominal and intravesical pressures during cystometry in conscious rats-effects of bladder outlet obstruction and intravesical PGE2. Neurourol Urodyn. 2008. 27:88–95.
20. Kim OH, Jin LH, Yoon SM, Lee T. The value and limitations of intravesical prostaglandin E2 (PGE2)-induced bladder hyperactivity as an overactive bladder model in normal, conscious Sprague-Dawley rats. Korean J Urol. 2008. 49:526–532.
21. Spitsbergen JM, Clemow DB, McCarty R, Steers WD, Tuttle JB. Neurally mediated hyperactive voiding in spontaneously hypertensive rats. Brain Res. 1998. 790:151–159.
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