Title : Mechanism of action of a K+ channel activator BRL 38227 on ATP-sensitive K+ channels in mouse skeletal muscle fibres - Hussain_1994_J.Physiol_478 Pt 3_523 |
Author(s) : Hussain M , Wareham AC , Head SI |
Ref : The Journal of Physiology , 478 Pt 3 :523 , 1994 |
Abstract :
1. Investigations were made into the effects of BRL 38227, a potassium channel activator, on ATP-sensitive potassium channels (K+ATP channels) in single fibres dissociated from the flexor digitorum brevis muscle of C57BL/6J mice. 2. In cell-attached patches BRL 38227 (100 microM) caused activation of a glibenclamide-sensitive potassium current. Linear slope conductance of the inward current, partial rectification of the outward current and glibenclamide sensitivity indicate that K+ATP channels are the site of action of BRL 38227. 3. In the absence of ATP at the cytoplasmic side of excised inside-out patches, BRL 38227 caused direct and magnesium-dependent activation of K+ATP channels. The degree of activation diminished with successive applications of BRL 38227. 4. BRL 38227 also caused activation of K+ATP channels in the presence of low (< 100 microM) but not high (1.0 mM) ATP, particularly in patches containing large numbers of channels. 5. BRL 38227 and 5 microM MgATP failed to activate channels following complete run-down. 6. Results show that BRL 38227 caused direct activation of K+ATP in skeletal muscle and that this was mediated through a magnesium-dependent binding site rather than alleviation of inhibition by competitive displacement of ATP from the inhibitory site. |
PubMedSearch : Hussain_1994_J.Physiol_478 Pt 3_523 |
PubMedID: 7965862 |
Hussain M, Wareham AC, Head SI (1994)
Mechanism of action of a K+ channel activator BRL 38227 on ATP-sensitive K+ channels in mouse skeletal muscle fibres
The Journal of Physiology
478 Pt 3 :523
Hussain M, Wareham AC, Head SI (1994)
The Journal of Physiology
478 Pt 3 :523