Acclimatization to high-altitude, long-term hypoxia (LTH) reportedly alters cerebral artery contraction-relaxation responses associated with changes in K(+) channel activity. We hypothesized that to maintain oxygenation during LTH, basilar arteries (BA) in the ovine adult and near-term fetus would show increased large-conductance Ca(2+) activated potassium (BK) channel activity. We measured BK ...

Vasoinhibins, a family of antiangiogenic peptides derived from prolactin proteolysis, inhibit the vascular effects of several proangiogenic factors, including bradykinin (BK). Here, we report that vasoinhibins block the BK-induced proliferation of bovine umbilical vein endothelial cells. This effect is mediated by the inactivation of endothelial nitric oxide synthase (eNOS), as the NO donor DET...

BACKGROUND In the central nervous system ethanol (EtOH) is metabolized to acetaldehyde (ACA) primarily by the oxidative enzyme catalase. Evidence suggests that ACA is responsible for at least some of the effects on the brain that have been attributed to EtOH. Various types of ion channels which are involved in electrical signaling are targets of EtOH like maxi calcium-activated potassium (BK) c...

Large conductance Ca(2+)-activated K(+) (BK) channels consist of pore-forming α- and accessory β-subunits. There are four β-subunit subtypes (β1-β4), BK β1-subunit is specific for smooth muscle cells (SMC). Reduced BK β1-subunit expression is associated with SMC dysfunction in animal models of human disease, because downregulation of BK β1-subunit reduces channel activity and increases SMC cont...

Plasma membrane large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels and sarcoplasmic reticulum inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)Rs) are expressed in a wide variety of cell types, including arterial smooth muscle cells. Here, we studied BK(Ca) channel regulation by IP(3) and IP(3)Rs in rat and mouse cerebral artery smooth muscle cells. IP(3) activated BK(Ca) channels bo...

Large conductance calcium-activated potassium (BK) channels play a key role in the control of neuronal activity. Ethanol is a potent activator of BK channel gating, but how this action may impact ethanol drinking still remains poorly understood. Auxiliary β subunits are known to modulate ethanol-induced potentiation of BK currents. In the present study, we investigated whether BK β1 and β4 subu...

Large-conductance Ca(2+)-activated K(+) (BK) channels are reported to be essential for NADPH oxidase-dependent microbial killing and innate immunity in leukocytes. Using human peripheral blood and mouse bone marrow neutrophils, pharmacological targeting, and BK channel gene-deficient (BK(-/-)) mice, we stimulated NADPH oxidase activity with 12-O-tetradecanoylphorbol-13-acetate (PMA) and perform...

In this paper we study properties of intersection graphs of kbend paths in the rectangular grid. A k-bend path is a path with at most k 90 degree turns. The class of graphs representable by intersections of k-bend paths is denoted by Bk-VPG. We show here that for every fixed k, Bk-VPG ( Bk+1-VPG and that recognition of graphs from Bk-VPG is NP-complete even when the input graph is given by a Bk...

CaV-channel dependent activation of BK channels is critical for feedback control of both calcium influx and cell excitability. Here we addressed the functional and spatial interaction between BK and CaV1.3 channels, unique CaV1 channels that activate at low voltages. We found that when BK and CaV1.3 channels were co-expressed in the same cell, BK channels started activating near -50 mV, ~30 mV ...

Large-conductance Ca2+-voltage-activated K+ channels (BK channels) control many key physiological processes, such as neurotransmitter release and muscle contraction. A signature feature of BK channels is that they have the largest single channel conductance of all K+ channels. Here we examine the mechanism of this large conductance. Comparison of the sequence of BK channels to lower-conductance...