scholarly journals Active mechanical properties of the smooth muscle of the urinary bladder

1979 ◽  
Vol 17 (3) ◽  
pp. 281-290 ◽  
Author(s):  
D. J. Griffiths ◽  
R. van Mastrigt ◽  
W. A. van Duyl ◽  
B. L. R. A. Coolsaet
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Urinary Bladder

Investigation of Fiber-Driven Mechanical Behavior of Human and Porcine Bladder Tissue Tested Under Identical Conditions

2021 ◽  
Author(s):  
Tyler G Tuttle ◽  
Duncan Morhardt ◽  
Andrea Poli ◽  
John M. Park ◽  
Ellen M. Arruda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Urinary Bladder ◽  
Mechanical Characteristics ◽  
Large Deformations ◽  
Amorphous Matrix ◽  
Longitudinal Direction ◽  
Human Bladder ◽  
Bladder Tissue ◽  
Material Models

Abstract The urinary bladder is a highly dynamic organ, that undergoes large deformations several times a day. Mechanical characteristics of the tissue are crucial in determining the function, and dysfunction, of the organ. Yet, literature reporting on the mechanical properties of human bladder tissue is scarce and, at times, contradictory. In this study, we focused on mechanically testing tissue from both human and pig bladders using identical protocols, to validate the use of pigs as a model for the human bladder. Furthermore, we tested the effect on tissue mechanical properties of two treatments, elastase to digest elastin fibers and oxybutynin to reduce smooth muscle cells spasticity, as well as of the anatomical direction of testing. We also implemented two different material models to aid in the interpretation of the experimental results. We found that human tissue behaves similarly to pig tissue at high deformations (collagen-dominated behavior) while we detected differences between the species at low deformations (amorphous matrix-dominated behavior). Our results also suggest that elastin could play a role in determining the behavior of the collagen fibers network. Finally, we confirmed the anisotropy of the tissue which reached higher stresses in the transverse when compared to the longitudinal direction.

Active Biaxial Mechanical Properties of Bladder Wall Tissue

2003 ◽  
Author(s):  
Jiro Nagatomi ◽  
Michael B. Chancellor ◽  
Michael S. Sacks
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Urinary Bladder ◽  
Muscle Tone ◽  
Bladder Wall ◽  
Upper Urinary Tract ◽  
Biaxial Stress ◽  
Bladder Tissue ◽  
Biaxial Mechanical Properties

The urinary bladder is a smooth muscle organ whose main functions are to store and to void urine. Since the most important aspect of the storage function of the bladder is to maintain low intravesical pressure in order to protect the upper urinary tract from backflow of urine, the compliance of the bladder wall is one of the key functional paramters to assess the health of this organ. Previously, our laboratory reported, for the first time, the biaxial mechanical properties of bladder wall tissue in the inactive state (in the absence of calcium in the testing bath solution and thus smooth muscle contraction was abolished) (Gloeckner et al. 2002). The bladder in vivo, however, normaly exhibits passive smooth muscle tone during filling and active contraction during voiding. Therefore, in order to completely characterize the bladder tissue mechanical behaviors, it is necessary to examine the load-deformation relationship of the bladder under the passive and active states. In the present study, a novel experimental model was designed to allow collection of biaxial stress-strain data from urinary bladder wall tissue under passive, active and inactive states.

scholarly journals Stretch-induced Calcium Release in Smooth Muscle

2002 ◽  
Vol 119 (6) ◽  
pp. 533-543 ◽  
Author(s):  
Guangju Ji ◽  
Robert J. Barsotti ◽  
Morris E. Feldman ◽  
Michael I. Kotlikoff
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Smooth Muscle Cells ◽  
Calcium Release ◽  
Muscle Cells ◽  
Intraluminal Pressure ◽  
Bladder Smooth Muscle ◽  
Urinary Bladder Smooth Muscle ◽  
Inward Currents ◽  
Longitudinal Stretch

Smooth muscle cells undergo substantial increases in length, passively stretching during increases in intraluminal pressure in vessels and hollow organs. Active contractile responses to counteract increased transmural pressure were first described almost a century ago (Bayliss, 1902) and several mechanisms have been advanced to explain this phenomenon. We report here that elongation of smooth muscle cells results in ryanodine receptor–mediated Ca2+ release in individual myocytes. Mechanical elongation of isolated, single urinary bladder myocytes to ∼120% of slack length (ΔL = 20) evoked Ca2+ release from intracellular stores in the form of single Ca2+ sparks and propagated Ca2+ waves. Ca2+ release was not due to calcium-induced calcium release, as release was observed in Ca2+-free extracellular solution and when free Ca2+ ions in the cytosol were strongly buffered to prevent increases in [Ca2+]i. Stretch-induced calcium release (SICR) was not affected by inhibition of InsP3R-mediated Ca2+ release, but was completely blocked by ryanodine. Release occurred in the absence of previously reported stretch-activated currents; however, SICR evoked calcium-activated chloride currents in the form of transient inward currents, suggesting a regulatory mechanism for the generation of spontaneous currents in smooth muscle. SICR was also observed in individual myocytes during stretch of intact urinary bladder smooth muscle segments. Thus, longitudinal stretch of smooth muscle cells induces Ca2+ release through gating of RYR. SICR may be an important component of the physiological response to increases in luminal pressure in smooth muscle tissues.

Ca2+ channel properties in smooth muscle cells of the urinary bladder from pig and human

2002 ◽  
Vol 443 (1-3) ◽  
pp. 19-29 ◽  
Author(s):  
Shunichi Kajioka ◽  
Shinsuke Nakayama ◽  
Gordon McMurray ◽  
Kihachiro Abe ◽  
Alison F. Brading
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Channel Properties

In vitro and in vivo relaxation of urinary bladder smooth muscle by the selective myosin II inhibitor, blebbistatin

2011 ◽  
Vol 107 (2) ◽  
pp. 310-317 ◽  
Author(s):  
Xinhua Zhang ◽  
Dwaraka Srinivasa R. Kuppam ◽  
Arnold Melman ◽  
Michael E. DiSanto
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Myosin Ii ◽  
Bladder Smooth Muscle ◽  
Urinary Bladder Smooth Muscle
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