Atp Dependent Potassium Channels
Mostrando 13-24 de 72 artigos, teses e dissertações.
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13. Lactate activates ATP-sensitive potassium channels in guinea pig ventricular myocytes.
The functional significance of cardiac ATP-sensitive potassium channels remains controversial because of the discrepancy between the low levels of ATP at which activation of the channels occurs and the much higher levels of ATP maintained during myocardial ischemia. We studied the effects of (+)-lactate, which accumulates in large quantity as a result of inc
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14. Mechanism of action of a K+ channel activator BRL 38227 on ATP-sensitive K+ channels in mouse skeletal muscle fibres.
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
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15. Phosphatidylinositol-4,5-bisphosphate, PIP2, controls KCNQ1/KCNE1 voltage-gated potassium channels: a functional homology between voltage-gated and inward rectifier K+ channels
Phosphatidylinositol-4,5-bisphosphate (PIP2) is a major signaling molecule implicated in the regulation of various ion transporters and channels. Here we show that PIP2 and intracellular MgATP control the activity of the KCNQ1/KCNE1 potassium channel complex. In excised patch–clamp recordings, the KCNQ1/KCNE1 current decreased spontaneously with time. This
Oxford University Press.
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16. Adenosine activates ATP-sensitive potassium channels in arterial myocytes via A2 receptors and cAMP-dependent protein kinase.
The mechanism by which the endogenous vasodilator adenosine causes ATP-sensitive potassium (KATP) channels in arterial smooth muscle to open was investigated by the whole-cell patch-clamp technique. Adenosine induced voltage-independent, potassium-selective currents, which were inhibited by glibenclamide, a blocker of KATP currents. Glibenclamide-sensitive c
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17. Potassium current inhibition by nonselective cation channel-mediated sodium entry in rat pheochromocytoma (PC-12) cells.
Under physiological conditions, nonselective cation (NSC) channels mediate the entry of cations into cells, the most important being Na+ and Ca2+. In contrast to the Ca(2+)-dependent signaling mechanisms, little is known about the consequences and the spatial distribution of intracellular [Na+] elevation. In this study we demonstrate that Na+ entry, during t
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18. KATP channel inhibition by ATP requires distinct functional domains of the cytoplasmic C terminus of the pore-forming subunit
ATP-sensitive potassium (“KATP”) channels are rapidly inhibited by intracellular ATP. This inhibition plays a crucial role in the coupling of electrical activity to energy metabolism in a variety of cells. The KATP channel is formed from four each of a sulfonylurea receptor (SUR) regulatory subunit and an inwardly rectifying potassium (Kir6.2) pore-formi
The National Academy of Sciences.
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19. Vasopressin directly closes ATP-sensitive potassium channels evoking membrane depolarization and an increase in the free intracellular Ca2+ concentration in insulin-secreting cells.
The effects of arginine-vasopressin (AVP) (0.01-1 microM) on membrane potential, [Ca2+]i and ATP-sensitive potassium channels have been studied in the insulin-secreting cell line RINm5F. In whole cells, with an average spontaneous cellular transmembrane potential of -64 +/- 3 mV (n = 33) and an average basal [Ca2+]i of 102 +/- 6 nM (n = 40), AVP evoked: (i)
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20. The effect of intracellular anions on ATP-dependent potassium channels of rat skeletal muscle.
1. We have used excised inside-out patches to study the effects of anions bathing the cytoplasmic surface of the membrane on ATP-dependent K+ channels of rat flexor digitorum brevis muscle. Channels were closed by ATP applied to the cytoplasmic face of the patch with a concentration for half-closure (Ki) of 14 microM, were highly selective for K+ and had uni
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21. Purinergically induced membrane fluidization in ciliary cells: characterization and control by calcium and membrane potential.
To examine the role of membrane dynamics in transmembrane signal transduction, we studied changes in membrane fluidity in mucociliary tissues from frog palate and esophagus epithelia stimulated by extracellular ATP. Micromolar concentrations of ATP induced strong changes in fluorescence polarization, possibly indicating membrane fluidization. This effect was
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22. A rate theory model for Mg2+ block of ATP-dependent potassium channels of rat skeletal muscle.
1. We have studied the block by intracellular Mg2+ (0.08-4mM) of ATP-dependent potassium channels (KATP channels) from rat skeletal muscle using inside-out excised sarcolemmal patches. The block is voltage dependent, is relieved by extracellular potassium and has rapid kinetics, allowing the use of amplitude distribution analysis to estimate on and off rates
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23. The effects of magnesium upon adenosine triphosphate-sensitive potassium channels in a rat insulin-secreting cell line.
1. The patch-clamp method of single-channel recording was applied to K+ channels which are inhibited by intracellular adenosine 5'-triphosphate (ATP: K+-ATP channels) in membrane patches obtained from the insulin-secreting cloned cell line RINm5F. 2. The magnitude of K+ currents flowing outwards through these K+-ATP channels was reduced by internal Mg2+ ions
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24. Identification and properties of an ATP-sensitive K+ current in rabbit sino-atrial node pacemaker cells.
1. Single myocytes were isolated from rabbit sino-atrial (SA) node by enzymatic dissociation. Spontaneous pacemaker activity, whole-cell and single-channel currents were recorded under conditions known to modulate ATP-sensitive K+ (KATP) channels. 2. The KATP channel openers, cromakalim and pinacidil, slowed or abolished the pacemaker activity, and caused hy