Activation of neuronal ATP-sensitive potassium (K ATP) channels is an important mechanism that protects neurons and conserves neural function during hypoxia. We investigated hypoxia (bath gassed with 95% N 2 /5% CO 2 vs. 95% O 2 /5% CO 2 in control) induced changes in K ATP current in second-order neurons of peripheral chemoreceptors in the nucleus of the solitary tract (NTS). Hypoxia-induced K...

Activation of neuronal ATP-sensitive potassium (K(ATP)) channels is an important mechanism that protects neurons and conserves neural function during hypoxia. We investigated hypoxia (bath gassed with 95% N(2)-5% CO(2) vs. 95% O(2)-5% CO(2) in control)-induced changes in K(ATP) current in second-order neurons of peripheral chemoreceptors in the nucleus of the solitary tract (NTS). Hypoxia-induc...

Rho transcription termination factor mutant, F355W, showed tryptophan fluorescence intensity approximately twice that of wild-type Rho at equivalent protein concentrations and underwent a decrease in relative fluorescence intensity at 350 nm when 100 microm ATP was added in the presence or absence of RNA. Titration of this fluorescence quenching with varying concentrations of ATP (0-600 microm)...

ATP-sensitive potassium channels (K(ATP) channels) regulate cell excitability in response to metabolic changes. K(ATP) channels are formed as a complex of a sulfonylurea receptor (SURx), a member of the ATP-binding cassette protein family, and an inward rectifier K(+) channel subunit (Kir6.x). Membrane phospholipids, in particular phosphatidylinositol (PI) 4,5-bisphosphate (PIP(2)), activate K(...

A B S T R A C T Introduction: Even today there is no effective drug therapy to prevent neuronal loss after brain stroke. In the present study we studied the effect of mitochondrial KATP channel regulators on neuronal ultrastructure after ischemia reperfusion in the rat. Materials & Methods: Rats temporarily subjected to four vessels occlusion for 15 minutes followed by 24 hours reperfusion with...

background: the mechanisms underlying cerebral hypercapnic vasodilatation are not fully understood.   objective: to investigate the role of nitric oxide (no) and atp-sensitive potassium (k atp ) channels in basal blood flow regulation and hypercapnia-induced vasodilatation in rabbit cerebral blood vessels.   methods: the change in cerebral blood flow was measured by a laser doppler flowmeter in...

Levosimendan, a new Ca++-sensitizing and positive inotropic agent, was reported to act as a coronary vasodilator and protect ischemic myocardium. To elucidate the mechanisms of these actions, the possible electrophysiological effects of levosimendan on isolated rat ventricular cells were examined by the patch-clamp technique with whole-cell and single-channel recordings. Levosimendan (3 and 10 ...

BACKGROUND Accumulating evidence suggests that mitochondrial rather than sarcolemmal adenosine triphosphate-sensitive K+ (K(ATP)) channels may have an important role in the protection of myocardium during ischemia. Because both lidocaine and mexiletine are frequently used antiarrhythmic drugs during myocardial ischemia, it is important to investigate whether they affect mitochondrial K(ATP) cha...

Since, in addition to its growth-promoting actions, insulin-like growth factor-I (IGF-I) has rapid vasoactive actions, we investigated the effects of IGF-I on whole-cell ATP-sensitive K(+) (K(ATP)) currents of rat mesenteric arterial smooth muscle cells. IGF-I (10 or 30 nM) reduced K(ATP) currents activated by pinacidil or a membrane permeant cAMP analogue. Inhibition of phospholipase C, protei...

1. K(+) did not affect the Mg(2+)-dependent transphosphorylation but markedly increased the Na(+)-stimulated ADP-ATP exchange rate mediated by a microsomal fraction from guinea-pig kidney. 2. Rb(+), Cs(+), NH(4) (+) and Li(+) were equally effective in stimulating the Na(+)-dependent ADP-ATP exchange activity. 3. Treatment of the microsomal fraction with N-ethylmaleimide or increased concentrati...