225The effects of the flavonoid on urinary bladder smooth muscle contractility

2005 ◽  
Vol 4 (3) ◽  
pp. 59
Author(s):  
M. Dambros ◽  
G. Van Koeveringe ◽  
R. De Jongh ◽  
P. Van Kerrebroek ◽  
C. Riccetto ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Bladder Smooth Muscle ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Urinary Bladder Smooth Muscle

The Inhibitory Effect of the Flavonoid Galangin on Urinary Bladder Smooth Muscle Contractility is Mediated in Part by Modulation of Ca2+Release from Intracellular Stores

Planta Medica ◽  
2005 ◽  
Vol 71 (10) ◽  
pp. 962-964 ◽  
Author(s):  
Miriam Dambros ◽  
Marjanka van Deutekom ◽  
Rik de Jongh ◽  
Gommert A van Koeveringe ◽  
Jo G. De Mey ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Inhibitory Effect ◽  
Bladder Smooth Muscle ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Urinary Bladder Smooth Muscle

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.

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