Pharmacological and molecular analysis of ATP-sensitive K+ channels in the pig and human detrusor

Buckner, Steven A.; Milicic, Ivan; Daza, Anthony V.; Davis-Taber, Rachel; Scott, Victoria E.; Sullivan, James P.; Brioni, Jorge D.

doi:10.1016/s0014-2999(00)00388-5

Cited by 64 publications

(49 citation statements)

References 32 publications

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“…when the mean amplitude of the pinacidil-induced channel activity was normalized as one (n ¼ 4). Buckner et al, 2000). Thus, until our study, no functional study has yet been undertaken in smooth muscle K ATP channels to establish the involvement of SUR1 subunits.…”

Section: T Yunoki Et Almentioning

confidence: 93%

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels

Yunoki

Teramoto

Ito

2003

British J Pharmacology

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1 We have investigated the possible roles of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP-sensitive K + channels (K ATP channels) by use of patch-clamp and reverse transcriptase -polymerase chain reaction (RT -PCR) techniques. 2 In voltage-clamp experiments, not only diazoxide, a SUR1 and weak SUR2B activator, but also pinacidil, a selective SUR2 activator, caused an inward current at a holding potential of À50 mV in symmetrical 140 mM K + conditions. 3 Gliclazide (p1 mM), a selective SUR1 blocker, inhibited the 10 mM pinacidil-induced currents (K i ¼ 177 mM) and the 500 mM diazoxide-induced currents (high-affinity site, K i1 ¼ 5 nM; low-affinity site, K i2 ¼ 108 mM) at À50 mV. 4 Application of tolbutamide (p100 mM) reversibly caused an inhibition of the 500 mM diazoxideinduced current at -50 mV. 5 MCC-134, a SUR type-specific K ATP channel regulator (1 -100 mM), produced a concentrationdependent inward K + current, which was suppressed by the application of glibenclamide at À50 mV. The amplitude of the MCC-134 (100 mM)-induced current was approximately 50% of that of the 100 mM pinacidil-induced currents. 6 Using cell-attached configuration, MCC-134 activated a glibenclamide-sensitive K ATP channel which was also activated by pinacidil. 7 RT -PCR analysis demonstrated the presence of SUR1 and SUR2B transcripts in pig urethra. 8 These results indicate that both SUR1 and SUR2B subunits play a functional role in regulating the activity of pig urethral K ATP channels and that SUR1 contributes less than 25% to total K ATP currents.

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Section: T Yunoki Et Almentioning

confidence: 93%

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels

Yunoki

Teramoto

Ito

2003

British J Pharmacology

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“…i. K ATP Channels. The presence of mRNA for sulfonylurea receptors has been demonstrated in both pig and human detrusor (Buckner et al, 2000) and the ATPsensitive K ϩ (K ATP ) channels in the detrusor of e.g., guinea pigs have been characterized (Gopalakrishnan et al, 1999). These channels have been shown to be involved in the regulation of bladder contractility (Andersson, 1992;Bonev and Nelson, 1993a).…”

Section: Peripheral Targetsmentioning

confidence: 99%

Pharmacology of the Lower Urinary Tract: Basis for Current and Future Treatments of Urinary Incontinence

Andersson

Wein²

2004

Pharmacol Rev

455

364

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“…It has also been shown by other studies that hyperpolarization of the membrane of the detrusor smooth muscle could be induced through activation of various K + channels. Voltage-dependent K + channels [21] , ATP-sensitive K + channels [22] , K Ca channels [23] and TREK-1 (K 2P 2.1)channels [24] have been identified in the human detrusor muscle. Using knockout mice, it was shown that the BK Ca channel plays an important role in slowing the excitability and contractility of the detrusor smooth muscle [25] .…”

Section: Discussionmentioning

confidence: 99%

Potentiation of Potassium Currents by Beta-Adrenoceptor Agonists in Human Urinary Bladder Smooth Muscle Cells: A Possible Electrical Mechanism of Relaxation

Takemoto

Masumiya²,

Nunoki

et al. 2008

Pharmacology

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We examined the effects of β-adrenoceptor agonists on the membrane currents of smooth muscle cells from the human urinary bladder using a whole-cell patch clamp to investigate the involvement of Ca²⁺-activated K⁺ (K_Ca) channels in relaxation by β-adrenergic agonists. With 0.05 mmol/l EGTA in the patch pipette, depolarizing pulses evoked outward rectifying currents. Isoproterenol (1 µmol/l) significantly increased the membrane currents by 75% at +80 mV with 0.05 mmol/l EGTA pipette solution. BRL 37344 (1 µmol/l) significantly increased the membrane currents by 44% at +80 mV. Iberiotoxin (100 nmol/l) significantly decreased the membrane currents by 60% at +80 mV. In the presence of iberiotoxin, the potentiation of the outward currents by isoproterenol was greatly suppressed and, in the presence of iberiotoxin and apamin (1 µmol/l), the potentiation by isoproterenol was totally abolished. On the other hand, with 5 mmol/l EGTA pipette solution, depolarizing pulses evoked smaller outward currents. Isoproterenol (1 µmol/l) did not change the membrane currents with 5 mmol/l EGTA pipette solution. The real-time PCR analysis revealed the expression of β₂-adrenoceptors in the cells. These results suggest that Ca²⁺-activated and iberiotoxin- and apamin-sensitive currents via both large-conductance and small-conductance K_Ca channels could be increased by stimulation of β₂-adrenoceptors.

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Pharmacological and molecular analysis of ATP-sensitive K+ channels in the pig and human detrusor

Cited by 64 publications

References 32 publications

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels

Pharmacology of the Lower Urinary Tract: Basis for Current and Future Treatments of Urinary Incontinence

Potentiation of Potassium Currents by Beta-Adrenoceptor Agonists in Human Urinary Bladder Smooth Muscle Cells: A Possible Electrical Mechanism of Relaxation

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Pharmacological and molecular analysis of ATP-sensitive K+ channels in the pig and human detrusor

Cited by 64 publications

References 32 publications

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K+ channels

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K+ channels

Pharmacology of the Lower Urinary Tract: Basis for Current and Future Treatments of Urinary Incontinence

Potentiation of Potassium Currents by Beta-Adrenoceptor Agonists in Human Urinary Bladder Smooth Muscle Cells: A Possible Electrical Mechanism of Relaxation

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Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels

Functional involvement of sulphonylurea receptor (SUR) type 1 and 2B in the activity of pig urethral ATP‐sensitive K⁺ channels