scholarly journals Ryanodine receptor type 2 deficiency changes excitation-contraction coupling and membrane potential in urinary bladder smooth muscle

2007 ◽  
Vol 582 (2) ◽  
pp. 489-506 ◽  
Author(s):  
Shingo Hotta ◽  
Kozo Morimura ◽  
Susumu Ohya ◽  
Katsuhiko Muraki ◽  
Hiroshi Takeshima ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Urinary Bladder ◽  
Ryanodine Receptor ◽  
Receptor Type ◽  
Bladder Smooth Muscle ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Urinary Bladder Smooth Muscle

Voltage dependence of the coupling of Ca2+ sparks to BKCa channels in urinary bladder smooth muscle

2001 ◽  
Vol 280 (3) ◽  
pp. C481-C490 ◽  
Author(s):  
Gerald M. Herrera ◽  
Thomas J. Heppner ◽  
Mark T. Nelson
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Urinary Bladder ◽  
Voltage Dependence ◽  
Critical Role ◽  
Current Amplitude ◽  
Bladder Smooth Muscle ◽  
Bkca Channels ◽  
Current Frequency ◽  
Urinary Bladder Smooth Muscle

Large-conductance Ca2+-dependent K+(BKCa) channels play a critical role in regulating urinary bladder smooth muscle (UBSM) excitability and contractility. Measurements of BKCa currents and intracellular Ca2+ revealed that BKCa currents are activated by Ca2+ release events (Ca2+ sparks) from ryanodine receptors (RyRs) in the sarcoplasmic reticulum. The goals of this project were to characterize Ca2+ sparks and BKCa currents and to determine the voltage dependence of the coupling of RyRs (Ca2+ sparks) to BKCachannels in UBSM. Ca2+ sparks in UBSM had properties similar to those described in arterial smooth muscle. Most Ca2+ sparks caused BKCa currents at all voltages tested, consistent with the BKCa channels sensing ∼10 μM Ca2+. Membrane potential depolarization from −50 to −20 mV increased Ca2+ spark and BKCacurrent frequency threefold. However, membrane depolarization over this range had a differential effect on spark and current amplitude, with Ca2+ spark amplitude increasing by only 30% and BKCa current amplitude increasing 16-fold. A major component of the amplitude modulation of spark-activated BKCa current was quantitatively explained by the known voltage dependence of the Ca2+ sensitivity of BKCa channels. We, therefore, propose that membrane potential, or any other agent that modulates the Ca2+sensitivity of BKCa channels, profoundly alters the coupling strength of Ca2+ sparks to BKCa channels.

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.

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

Altered expression of thin filament-associated proteins in hypertrophied urinary bladder smooth muscle

2005 ◽  
Vol 25 (1) ◽  
pp. 78-88 ◽  
Author(s):  
Anita S. Mannikarottu ◽  
Michael E. DiSanto ◽  
Stephen A. Zderic ◽  
Alan J. Wein ◽  
Samuel Chacko
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Thin Filament ◽  
Bladder Smooth Muscle ◽  
Altered Expression ◽  
Associated Proteins ◽  
Urinary Bladder Smooth Muscle

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

Generation of a human urinary bladder smooth muscle cell line

2012 ◽  
Vol 48 (2) ◽  
pp. 84-96 ◽  
Author(s):  
Yongmu Zheng ◽  
Shaohua Chang ◽  
Ettickan Boopathi ◽  
Sandra Burkett ◽  
Mary John ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Smooth Muscle Cell ◽  
Cell Line ◽  
Muscle Cell ◽  
Bladder Smooth Muscle ◽  
Human Urinary Bladder ◽  
Urinary Bladder Smooth Muscle ◽  
Bladder Smooth Muscle Cell ◽  
Muscle Cell Line
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