scholarly journals BK channel activation with NS1619 decreases excitability and contractility of human urinary bladder smooth muscle

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Shankar Prasad Parajuli ◽  
Kiril Hristov ◽  
Rupal Pandey ◽  
Eric S Rovner ◽  
Georgi Petkov
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Bk Channel ◽  
Bladder Smooth Muscle ◽  
Channel Activation ◽  
Human 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

Human urinary bladder smooth muscle is dependent on membrane cholesterol for cholinergic activation

2010 ◽  
Vol 634 (1-3) ◽  
pp. 142-148 ◽  
Author(s):  
Yulia Shakirova ◽  
Michiko Mori ◽  
Mari Ekman ◽  
Jonas Erjefält ◽  
Bengt Uvelius ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Membrane Cholesterol ◽  
Bladder Smooth Muscle ◽  
Human Urinary Bladder ◽  
Urinary Bladder Smooth Muscle ◽  
Cholinergic Activation

scholarly journals Stimulation of β3-adrenoceptors relaxes rat urinary bladder smooth muscle via activation of the large-conductance Ca2+-activated K+ channels

2008 ◽  
Vol 295 (5) ◽  
pp. C1344-C1353 ◽  
Author(s):  
Kiril L. Hristov ◽  
Xiangli Cui ◽  
Sean M. Brown ◽  
Lei Liu ◽  
Whitney F. Kellett ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Bk Channels ◽  
Bk Channel ◽  
Bladder Smooth Muscle ◽  
Rat Urinary Bladder ◽  
Urinary Bladder Smooth Muscle ◽  
Brl 37344 ◽  
Stimulation Of

We investigated the role of large-conductance Ca2+-activated K+ (BK) channels in β3-adrenoceptor (β3-AR)-induced relaxation in rat urinary bladder smooth muscle (UBSM). BRL 37344, a specific β3-AR agonist, inhibits spontaneous contractions of isolated UBSM strips. SR59230A, a specific β3-AR antagonist, and H89, a PKA inhibitor, reduced the inhibitory effect of BRL 37344. Iberiotoxin, a specific BK channel inhibitor, shifts the BRL 37344 concentration response curves for contraction amplitude, net muscle force, and tone to the right. Freshly dispersed UBSM cells and the perforated mode of the patch-clamp technique were used to determine further the role of β3-AR stimulation by BRL 37344 on BK channel activity. BRL 37344 increased spontaneous, transient, outward BK current (STOC) frequency by 46.0 ± 20.1%. In whole cell mode at a holding potential of Vh = 0 mV, the single BK channel amplitude was 5.17 ± 0.28 pA, whereas in the presence of BRL 37344, it was 5.55 ± 0.41 pA. The BK channel open probability was also unchanged. In the presence of ryanodine and nifedipine, the current-voltage relationship in response to depolarization steps in the presence and absence of BRL 37344 was identical. In current-clamp mode, BRL 37344 caused membrane potential hyperpolarization from −26.1 ± 2.1 mV (control) to −29.0 ± 2.2 mV. The BRL 37344-induced hyperpolarization was eliminated by application of iberiotoxin, tetraethylammonium or ryanodine. The data indicate that stimulation of β3-AR relaxes rat UBSM by increasing the BK channel STOC frequency, which causes membrane hyperpolarization and thus relaxation.

scholarly journals Frequency encoding of cholinergic- and purinergic-mediated signaling to mouse urinary bladder smooth muscle: modulation by BK channels

2007 ◽  
Vol 292 (1) ◽  
pp. R616-R624 ◽  
Author(s):  
Matthias E. Werner ◽  
Anna-Maria Knorn ◽  
Andrea L. Meredith ◽  
Richard W. Aldrich ◽  
Mark T. Nelson
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Bk Channels ◽  
Bk Channel ◽  
Detrusor Muscle ◽  
Wild Type ◽  
Bladder Smooth Muscle ◽  
Overactive Detrusor ◽  
Maximal Force ◽  
Urinary Bladder Smooth Muscle

In the urinary bladder, contractions of the detrusor muscle and urine voiding are induced by the neurotransmitters ACh and ATP, released from parasympathetic nerves. Activation of K+ channels, in particular the large-conductance Ca2+-activated K+ (BK) channels, opposes increases in excitability and contractility of urinary bladder smooth muscle (UBSM). We have shown that deleting the gene mSlo1 in mice ( Slo−/−), encoding the BK channel, leads to enhanced nerve-mediated and neurotransmitter-dependent contractility of UBSM ( 38 ). Here, we examine the location of the BK channel in urinary bladder strips from mouse. Immunohistochemical analysis revealed that the channel is expressed in UBSM but not in nerves that innervate the smooth muscle. The relationship between electrical field stimulation and force generation of the cholinergic and purinergic pathways was examined by applying blockers of the respective receptors in UBSM strips from wild-type and from Slo−/− (knockout) mice. In wild-type strips, the stimulation frequency required to obtain a half-maximal force was significantly lower for the purinergic (7.2 ± 0.3 Hz) than the cholinergic pathway (19.1 ± 1.5 Hz), whereas the maximum force was similar. Blocking BK channels with iberiotoxin or ablation of the Slo gene increased cholinergic- and purinergic-mediated force at low frequencies, i.e., significantly decreased the frequency for a half-maximal force. Our results indicate that the BK channel has a very significant role in reducing both cholinergic- and purinergic-induced contractility and suggest that alterations in BK channel expression or function could contribute to pathologies such as overactive detrusor.

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