Ion conduction and selectivity properties of KcsA, a bacterial ion channel of known structure, were studied in a planar lipid bilayer system at the single-channel level. Selectivity sequences for permeant ions were determined by symmetrical solution conductance (K Rb , NH 4 , Tl Cs , Na , Li ) and by reversal potentials under bi-ionic or mixed-ion conditions (Tl K Rb NH 4 Na , Li ). Determinati...

The opening rate of voltage-gated potassium ion channels exhibits a characteristic knee-like turnover where the common exponential voltage dependence changes suddenly into a linear one. An explanation of this puzzling crossover is put forward in terms of a stochastic first passage time analysis. The theory predicts that the exponential voltage dependence correlates with the exponential distribu...

The characteristics of potassium channel block by a diverse group of quaternary ammonium (QA) ions was examined in squid axons. Altering the size and nature of the head and/or tail groups of the QA ions applied internally produced only quantitative differences in the potassium current block. Although their entry rate is diminished, compounds with head groups as large as 11 X 12 A are capable of...

oxLDL peptide vaccine and its antibody adoptive transferring have shown a significantly preventive or therapeutic effect in atherosclerotic animal model. The molecular mechanism behind this is obscure. Here, we report that oxLDL induces MCP-1 release in monocytes/macrophages through their TLR-4 (Toll-like receptor 4) and ERK MAPK pathway and is calcium/potassium channel-dependent. Using blockin...

The cell-attached configuration of the patch-clamp technique was used to investigate the effects of taurine on the basolateral potassium channels of rabbit proximal convoluted tubule. In the absence of taurine, the previously reported ATP-blockable channel, KATP, was observed in 51% of patches. It is characterized by an inwardly rectifying current-voltage curve with an inward slope conductance ...

The present study reports a microwave-assisted method for the synthesis of twelve novel tricyclic 1,4-dihydropyridine derivatives in which dimethyl-substituted cyclohexane and / or tetrahydrothiophene rings are fused to the DHP ring. The structures of the compounds were confirmed by spectral methods and elemental analysis. The potassium channel opening effects of the compounds were determined o...

BACKGROUND Recent studies have demonstrated that atrial electrical remodeling was an important contributing factor for the occurrence, persistence and maintenance of atrial fibrillation. The expression changes of ionic channels, especially L-type calcium channel and potassium channel Kv4.3, were the important molecular mechanism of atrial electrical remodeling. This study aimed to observe the e...

In recent years, withdrawal of marketed drugs including sertindole, grepafloxacin, and terfenadine owing to prolongation of the length of time between the start of the Q wave and end of the T wave on an electrocardiogram (QT interval) has prompted considerable effort in trying to establish the molecular basis of this potentially lethal phenomenon. In the majority of cases, those chemical entiti...

Bednarczyk P, Koziel A, Jarmuszkiewicz W, Szewczyk A. Large-conductance Ca -activated potassium channel in mitochondria of endothelial EA.hy926 cells. Am J Physiol Heart Circ Physiol 304: H1415–H1427, 2013. First published March 29, 2013; doi:10.1152/ajpheart.00976.2012.—In the present study, we describe the existence of a large-conductance Ca -activated potassium (BKCa) channel in the mitochon...

Flow-mediated vasodilation is endothelium dependent. We hypothesized that flow activates a potassium channel on the endothelium, and that activation of this channel leads to the release of the endogenous nitrovasodilator, nitric oxide. To test this hypothesis, rabbit iliac arteries were perfused at varying flow rates, at a constant pressure of 60 mm Hg. Increments in flow induced proportional i...