scholarly journals Changes in Urinary Bladder Smooth Muscle Contractility and the Role of Rho Kinase and Isoprostane after Partial Bladder outlet Obstruction in rats

2012 ◽  
Vol 32 (2) ◽  
pp. 1-16
Author(s):  
Abeer Dief ◽  
Adham Mohamed ◽  
Gehan Sharara
Keyword(s):  
Smooth Muscle ◽  
Bladder Outlet Obstruction ◽  
Rho Kinase ◽  
Outlet Obstruction ◽  
Bladder Smooth Muscle ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Partial Bladder Outlet Obstruction ◽  
Urinary Bladder Smooth Muscle

Obstruction-induced changes in urinary bladder smooth muscle contractility: a role for Rho kinase

2003 ◽  
Vol 285 (5) ◽  
pp. F990-F997 ◽  
Author(s):  
Wu Bing ◽  
Shaohua Chang ◽  
Joseph A. Hypolite ◽  
Michael E. DiSanto ◽  
Stephen A. Zderic ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Rabbit Model ◽  
Rho Kinase ◽  
Outlet Obstruction ◽  
Slow Relaxation ◽  
Bladder Smooth Muscle ◽  
Smooth Muscle Contractility ◽  
Slow Development ◽  
Urinary Bladder Smooth Muscle ◽  
Force Maintenance

Detrusor smooth muscle (DSM) undergoes hypertrophy after partial bladder outlet obstruction (PBOO) in male rabbits, as it does in men with PBOO induced by benign prostatic hyperplasia. Despite detrusor hypertrophy, some bladders are severely dysfunctional (decompensated). In this study, the rabbit model for PBOO was used to determine the biochemical regulation of the contractile apparatus and force maintenance by the detrusor from decompensated bladders (DB). Bladders from sham-operated rabbits served as a control. On stimulation with 125 mM KCl, the DSM from sham-operated (SB) rabbits showed phasic contractions, whereas the detrusor from DB was tonic, exhibiting slow development of force, a longer duration of force maintenance, and slow relaxation. The Rho kinase (ROK) inhibitor Y-27632 enhanced the relaxation of precontracted DSM strips from DB. The enhancement of relaxation of the KCl-induced contraction of DB by Y-27632 was associated with dephosphorylation of myosin light chain (MLC20). The DSM extract from DB showed low phosphatase activity compared with that from SB. The DB also showed more Ca2+-independent MLC20 phosphorylation, which was partially inhibited by Y-27632. RT-PCR and Western blotting revealed similar expression levels of MLC kinase and ROK-α in SB and DB, but ROK-β was overexpressed in DB. These results suggest that the ROK-mediated pathway is partly responsible for the high degree of force maintenance and slow relaxation in the detrusor from DB.

scholarly journals Expression and functional role of Rho-kinase in rat urinary bladder smooth muscle

2003 ◽  
Vol 138 (5) ◽  
pp. 757-766 ◽  
Author(s):  
Alexandra Wibberley ◽  
Zunxuan Chen ◽  
Erding Hu ◽  
J Paul Hieble ◽  
Timothy D Westfall
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Functional Role ◽  
Rho Kinase ◽  
Bladder Smooth Muscle ◽  
Rat Urinary Bladder ◽  
Urinary Bladder Smooth Muscle

Partial bladder outlet obstruction alters Ca2+ sensitivity of force, but not of MLC phosphorylation, in bladder smooth muscle

2003 ◽  
Vol 285 (4) ◽  
pp. F703-F710 ◽  
Author(s):  
Michaela C. Stanton ◽  
Michele Clement ◽  
Edward J. Macarak ◽  
Stephen A. Zderic ◽  
Robert S. Moreland
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Bladder Outlet Obstruction ◽  
Outlet Obstruction ◽  
Muscle Cells ◽  
Maximal Velocity ◽  
Bladder Smooth Muscle ◽  
Partial Bladder Outlet Obstruction ◽  
Velocity Of Shortening ◽  
Mlc Phosphorylation

Partial bladder outlet obstruction in the rabbit produces changes in bladder function similar to those seen clinically in patients with obstructive uropathies. Whole organ function is significantly altered, as are the smooth muscle cells inside the bladder wall. This study was designed to determine whether outlet obstruction alters smooth muscle function at the level of contractile filaments. Rabbit bladders were partially obstructed for 2 wk. Triton X-100 was used to provide a detergent-skinned bladder smooth muscle preparation that would allow control of the intracellular environment while the ability to shorten and develop force is maintained. Ca2+-force and Ca2+-myosin light chain (MLC) phosphorylation relations and maximal velocity of shortening were determined. The Ca2+ sensitivity of force was significantly lower in tissues from animals subjected to outlet obstruction compared with tissues from control animals. In contrast, no difference was noted in the Ca2+ sensitivity of MLC phosphorylation. Maximal levels of stress and MLC phosphorylation were similar in both animal groups. Maximal velocity of shortening was significantly slower in tissues from outlet-obstructed animals at all Ca2+ concentrations compared with tissues from control animals. Ultrastructurally, detergent skinning had little effect on structural integrity. Moreover, tissues from obstructed animals showed an increase in the number of sarcolemmal attachment plaque structures. We suggest that partial bladder outlet obstruction produces deleterious (e.g., decrease in Ca2+ sensitivity of force) and compensatory (e.g., increase in membrane attachment plaques) changes in bladder smooth muscle cells.

The effect of chronic partial bladder outlet obstruction on corpus cavernosum smooth muscle and Rho-kinase in rabbits

2008 ◽  
Vol 27 (8) ◽  
pp. 826-831 ◽  
Author(s):  
Wei-Yu Lin ◽  
Anita Mannikarottu ◽  
Paul Chichester ◽  
Paul Neuman ◽  
Arnold Johnson ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Bladder Outlet Obstruction ◽  
Corpus Cavernosum ◽  
Rho Kinase ◽  
Outlet Obstruction ◽  
Partial Bladder Outlet Obstruction
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