Blockade of Kv7 channels reverses the inhibitory effects of exchange protein directly activated by cAMP activation on purinergic contractions of the murine detrusor.

Purinergic contractions of the detrusor are reduced by cAMP, but the underlying mechanisms are unclear. We examined the effects of BK and Kv7 channel modulators on purinergic contractions of the detrusor and tested if the inhibitory effects of activators of the cAMP effectors, PKA and EPAC, were reduced by blockade of BK or Kv7 channels. Purinergic contractions of the murine detrusor were induced by electric field stimulation (EFS) or application of the P2X receptor agonist α,β-MeATP.

Functional expression of Na1.7 channels in freshly dispersed mouse bronchial smooth muscle cells.

Isolated smooth muscle cells (SMCs) from mouse bronchus were studied using the whole cell patch-clamp technique at ∼21°C. Stepping from -100 mV to -20 mV evoked inward currents of mean amplitude -275 pA. These inactivated (tau = 1.

Inhibitory effects of openers of large-conductance Ca-activated K channels on agonist-induced phasic contractions in rabbit and mouse bronchial smooth muscle.

Airway smooth muscle expresses abundant BK channels, but their role in regulating contractions remains controversial. This study examines the effects of two potent BK channel openers on agonist-induced phasic contractions in rabbit and mouse bronchi. First, we demonstrated the ability of 10 μM GoSlo-SR5-130 to activate BK channels in inside-out patches from rabbit bronchial myocytes, where it shifted the activation V by -88 ± 11 mV (100 nM Ca, n = 7).