Large-conductance calcium-activated potassium channels in purkinje cell plasma membranes are clustered at sites of hypolemmal microdomains

2009 ◽  
Vol 515 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Walter A. Kaufmann ◽  
Francesco Ferraguti ◽  
Yugo Fukazawa ◽  
Yu Kasugai ◽  
Ryuichi Shigemoto ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Purkinje Cell ◽  
Plasma Membranes ◽  
Cell Plasma ◽  
Calcium Activated Potassium Channels

scholarly journals BK channels in Purkinje cell plasma membranes are concentrated in plasmerosomes at sites of hypolemmal cisternae

2008 ◽  
Vol 8 (S1) ◽  
Author(s):  
Walter A Kaufmann ◽  
Francesco Ferraguti ◽  
Yugo Fukazawa ◽  
Yu Kasugai ◽  
Ryuichi Shigemoto ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Plasma Membranes ◽  
Bk Channels ◽  
Cell Plasma

scholarly journals Endothelium as target for large-conductance calcium-activated potassium channel openers.

2009 ◽  
Vol 56 (3) ◽  
Author(s):  
Antoni Wrzosek
Keyword(s):  
Endothelial Cells ◽  
Potassium Channels ◽  
Potassium Channel ◽  
Plasma Membranes ◽  
Inflammatory Responses ◽  
Critical Role ◽  
The Body ◽  
Pharmacological Intervention ◽  
Ca Channels ◽  
Calcium Activated Potassium Channels

The endothelium is a highly active organ responsible for vasculatory tone and structure, angiogenesis, as well as hemodynamic, humoral, and inflammatory responses. The endothelium is constantly exposed to blood flow, sheer stress and tension. Endothelial cells are present as a vasculature in every tissue of the body and react to and control its microenvironment. A variety of ion channels are present in the plasma membranes of endothelial cells. These include potassium channels such as inwardly rectifying potassium (K(ir)) channels, voltage-dependent (K(v)) channels, ATP-regulated potassium (K(ATP)) channels and three types of calcium-activated potassium channels (K(Ca)), the large (BK(Ca)), intermediate (IK(Ca)), and small (SK(Ca)) -conductance potassium channels. Potassium current plays a critical role in action potentials in excitable cells, in setting the resting membrane potential, and in regulating neurotransmitter release. Mitochondrial isoforms of potassium channel contribute to the cytoprotection of endothelial cells. Prominent among potassium channels are families of calcium-activated potassium channels, and especially large-conductance calcium-activated potassium channels. The modulation of BK(Ca) channels, which are voltage- and calcium-dependent, has been intensively studied. The BK(Ca) channels show large expression dynamics in endothelial cells and tissue-specific expression of large numbers of alternatively spliced isoforms. In this review, a few examples of the modulatory mechanisms and physiological consequences of the expression of BK(Ca) channels are discussed in relation to potential targets for pharmacological intervention.

scholarly journals Downregulation of Purkinje Cell Activity by Modulators of Small Conductance Calcium-Activated Potassium Channels In Rat Cerebellum

Acta Naturae ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 91-99 ◽  
Author(s):  
T. V. Karelina ◽  
Yu. D. Stepanenko ◽  
P. A. Abushik ◽  
D. A. Sibarov ◽  
S. M. Antonov
Keyword(s):  
Potassium Channels ◽  
Purkinje Cell ◽  
Cell Activity ◽  
Spike Frequency ◽  
Specific Marker ◽  
Sk Channels ◽  
Simple Spike ◽  
Sk Channel ◽  
Calcium Activated Potassium Channels ◽  
Small Conductance

Small-conductance calcium-activated potassium channels (SK channels) are widely expressed in CNS tissues. Their functions, however, have not been well studied. Participation of SK channels in Purkinje cell (PC) pacemaker activity has been studied predominantly in vitro. Here we studied for the first time the effects of SK channel activation by NS309 or CyPPA on the PC simple spike frequency in vivo in adult (3 - 6 months) and aged (22 - 28 months) rats using extracellular microelectrode recordings. Both pharmacological agents caused a statistically significant decrease in the PC simple spike frequency. The maximum value of the decrease in the simple spike frequency did not depend on age, whereas a statistically significant inhibition of the spike frequency was achieved faster in aged animals than in adult ones. In experiments on cultured neurons PCs were identified by the expression of calbindin as the PC-specific marker. Registration of transmembrane currents in cerebellar neurons revealed the direct action of NS309 and CyPPA on the SK channels of PC consisted in the enhancement of outward potassium currents and action potential after-hyperpolarization. Thus, SK channel activators can compensate for age-related changes of the autorhythmic functions of the cerebellum.

scholarly journals Insulin-induced rapid decrease of a major protein in fat cell plasma membranes.

1984 ◽  
Vol 259 (19) ◽  
pp. 12112-12116
Author(s):  
E J Schoenle ◽  
L D Adams ◽  
D W Sammons
Keyword(s):  
Plasma Membranes ◽  
Rapid Decrease ◽  
Major Protein ◽  
Fat Cell ◽  
Cell Plasma

[125I]Iberiotoxin-D19Y/Y36F, the First Selective, High Specific Activity Radioligand for High-Conductance Calcium-Activated Potassium Channels

Biochemistry ◽  
1997 ◽  
Vol 36 (7) ◽  
pp. 1943-1952 ◽  
Author(s):  
Alexandra Koschak ◽  
Robert O. Koch ◽  
Jessica Liu ◽  
Gregory J. Kaczorowski ◽  
Peter H. Reinhart ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Specific Activity ◽  
High Specific Activity ◽  
Calcium Activated Potassium Channels ◽  
High Conductance

scholarly journals Charged anaesthetics alter LM-fibroblast plasma-membrane enzymes by selective fluidization of inner or outer membrane leaflets

1986 ◽  
Vol 239 (2) ◽  
pp. 301-310 ◽  
Author(s):  
W D Sweet ◽  
F Schroeder
Keyword(s):  
Plasma Membrane ◽  
Active Site ◽  
Plasma Membranes ◽  
Local Anaesthetics ◽  
Cationic Drugs ◽  
Cell Plasma ◽  
Composition And Structure ◽  
Highly Sensitive ◽  
Functional Consequences ◽  
Anionic Drugs

The functional consequences of the differences in lipid composition and structure between the two leaflets of the plasma membrane were investigated. Fluorescence of 1,6-diphenylhexa-1,3,5-triene(DPH), quenching, and differential polarized phase fluorimetry demonstrated selective fluidization by local anaesthetics of individual leaflets in isolated LM-cell plasma membranes. As measured by decreased limiting anisotropy of DPH fluorescence, cationic (prilocaine) and anionic (phenobarbital and pentobarbital) amphipaths preferentially fluidized the cytofacial and exofacial leaflets respectively. Unlike prilocaine, procaine, also a cation, fluidized both leaflets of these membranes equally. Pentobarbital stimulated 5′-nucleotidase between 0.1 and 5 mM and inhibited at higher concentrations, whereas phenobarbital only inhibited, at higher concentrations. Cationic drugs were ineffective. Two maxima of (Na+ + K+)-ATPase activation were obtained with both anionic drugs. Only one activation maximum was obtained with both cationic drugs. The maximum in activity below 1 mM for all four drugs clustered about a single limiting anisotropy value in the cytofacial leaflet, whereas there was no correlation between activity and limiting anisotropy in the exofacial leaflets. Therefore, although phenobarbital and pentobarbital below 1 mM fluidized the exofacial leaflet more than the cytofacial leaflet, the smaller fluidization in the cytofacial leaflet was functionally significant for (Na+ + K+)-ATPase. Mg2+-ATPase was stimulated at 1 mM-phenobarbital, unaffected by pentobarbital and slightly stimulated by both cationic drugs at concentrations fluidizing both leaflets. Thus the activity of (Na+ + K+)-ATPase was highly sensitive to selective fluidization of the leaflet containing its active site, whereas the other enzymes examined were little affected by fluidization of either leaflet.

scholarly journals Down-regulation of the Small Conductance Calcium-activated Potassium Channels in Diabetic Mouse Atria

2015 ◽  
Vol 290 (11) ◽  
pp. 7016-7026 ◽  
Author(s):  
Fu Yi ◽  
Tian-You Ling ◽  
Tong Lu ◽  
Xiao-Li Wang ◽  
Jingchao Li ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Diabetic Mouse ◽  
Down Regulation ◽  
Calcium Activated Potassium Channels ◽  
Small Conductance
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