keyword
MENU ▼
Read by QxMD icon Read
search

Potassium current voltage clamp

keyword
https://www.readbyqxmd.com/read/27861889/margatoxin-bound-quantum-dots-as-a-novel-inhibitor-of-the-voltage-gated-ion-channel-kv1-3
#1
Austin B Schwartz, Anshika Kapur, Wentao Wang, Zhenbo Huang, Erminia Fardone, Goutam Palui, Hedi Mattoussi, Debra Ann Fadool
Venom-derived ion channel inhibitors have strong channel selectivity, potency, and stability; however, tracking delivery to their target can be challenging. Herein, we utilized luminescent quantum dots (QDs) conjugated to margatoxin (MgTx) as a traceable vehicle to target a voltage-dependent potassium channel, Kv1.3, which has a select distribution and well characterized role in immunity, glucose metabolism, and sensory ability. We screened both unconjugated (MgTx) and conjugated MgTx (QD-MgTx) for their ability to inhibit Shaker channels Kv1...
November 8, 2016: Journal of Neurochemistry
https://www.readbyqxmd.com/read/27832077/high-frequency-resonance-in-the-gerbil-medial-superior-olive
#2
Jason Mikiel-Hunter, Vibhakar Kotak, John Rinzel
A high-frequency, subthreshold resonance in the guinea pig medial superior olive (MSO) was recently linked to the efficient extraction of spatial cues from the fine structure of acoustic stimuli. We report here that MSO neurons in gerbil also have resonant properties and, based on our whole-cell recordings and computational modeling, that a low-voltage-gated potassium current, IKLT, underlies the resonance. We show that resonance was lost following dynamic clamp replacement of IKLT with a leak conductance and in the model when voltage-gating of IKLT was suppressed...
November 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27796577/regulation-of-human-cardiac-kv1-5-channels-by-extracellular-acidification
#3
Shuang Wang, Wei-Guang Ding, Jia-Yu Bai, Futoshi Toyoda, Min-Jie Wei, Hiroshi Matsuura
Human Kv1.5 channels (hKv1.5) conduct the ultra-rapid delayed rectifier potassium current (I Kur), which plays an important role in action potential repolarization of atrial myocytes. The present study was undertaken to examine the effects of acidic pH on hKv1.5 wild-type (WT) and its pore mutant channels heterologously expressed in Chinese hamster ovary (CHO) cells using site-directed mutagenesis combined with whole-cell patch-clamp technique. Both extracellular and intracellular acidifications equally and reversely reduced the amplitude of hKv1...
October 28, 2016: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/27789942/comparison-of-cellular-effects-of-starch-coated-spions-and-poly-lactic-co-glycolic-acid-matrix-nanoparticles-on-human-monocytes
#4
Dominik Gonnissen, Ying Qu, Klaus Langer, Cengiz Öztürk, Yuliang Zhao, Chunying Chen, Guiscard Seebohm, Martina Düfer, Harald Fuchs, Hans-Joachim Galla, Kristina Riehemann
Within the last years, progress has been made in the knowledge of the properties of medically used nanoparticles and their toxic effects, but still, little is known about their influence on cellular processes of immune cells. The aim of our comparative study was to present the influence of two different nanoparticle types on subcellular processes of primary monocytes and the leukemic monocyte cell line MM6. We used core-shell starch-coated superparamagnetic iron oxide nanoparticles (SPIONs) and matrix poly(lactic-co-glycolic acid) (PLGA) nanoparticles for our experiments...
2016: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/27774053/calretinin-periglomerular-interneurons-in-mice-olfactory-bulb-cells-of-few-words
#5
Alex Fogli Iseppe, Angela Pignatelli, Ottorino Belluzzi
Within the olfactory bulb (OB), periglomerular (PG) cells consist of various types of interneurons, generally classified by their chemical properties such as neurotransmitter and calcium binding proteins. Calretinin (CR) characterizes morphologically and functionally the more numerous and one of the less known subpopulation of PG cells in the OB. Using of transgenic mice expressing eGFP under the CR promoter, we have tried to obtain the first functional characterization of these cells. Electrophysiological recordings were made in these cells using the patch-clamp technique in thin slices...
2016: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/27749895/a-parsimonious-model-of-the-rabbit-action-potential-elucidates-the-minimal-physiological-requirements-for-alternans-and-spiral-wave-breakup
#6
Richard A Gray, Pras Pathmanathan
Elucidating the underlying mechanisms of fatal cardiac arrhythmias requires a tight integration of electrophysiological experiments, models, and theory. Existing models of transmembrane action potential (AP) are complex (resulting in over parameterization) and varied (leading to dissimilar predictions). Thus, simpler models are needed to elucidate the "minimal physiological requirements" to reproduce significant observable phenomena using as few parameters as possible. Moreover, models have been derived from experimental studies from a variety of species under a range of environmental conditions (for example, all existing rabbit AP models incorporate a formulation of the rapid sodium current, INa, based on 30 year old data from chick embryo cell aggregates)...
October 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27747371/estradiol-modified-prolactin-secretion-independently-of-action-potentials-and-ca-2-and-blockade-of-outward-potassium-currents-in-gh3-cells
#7
Manuel Sánchez, Lorena Suárez, Begoña Cantabrana, Javier Bordallo
Estrogens facilitate prolactin (PRL) secretion acting on pituitary cells. In GH3 cells, estradiol induces acute action potentials and oscillations of intracellular Ca(2+) associated with the secretagogue function. Estradiol modulates several ion channels which may affect the action potential rate and the release of PRL in lactotroph cells, which might depend on its concentration. The aims were to characterize the acute effect of supraphysiological concentrations of estradiol on Ca(2+) and noninactivating K(+) currents and measure the effect on the spontaneous action potentials and PRL release in the somatolactotroph cell line, GH3...
October 17, 2016: Naunyn-Schmiedeberg's Archives of Pharmacology
https://www.readbyqxmd.com/read/27746193/the-plc-pkc-ras-mek-kv-channel-pathway-is-involved-in-uncarboxylated-osteocalcin-regulated-insulin-secretion-in-rats
#8
Jingying Gao, Tao Bai, Lele Ren, Yaqin Ding, Xiangqin Zhong, Hui Wang, Yangyan Guo, Jie Li, Yunfeng Liu, Yi Zhang
Uncarboxylated osteocalcin, a bone matrix protein, has been proposed to regulate glucose metabolism by increasing insulin secretion, improving insulin sensitivity and stimulating β cell proliferation. Our previous study also indicated that uncarboxylated osteocalcin stimulates insulin secretion by inhibiting voltage-gated potassium (KV) channels. The goal of this study is to further investigate the underlying mechanisms for the regulation of Kv channels and insulin secretion by uncarboxylated osteocalcin. Insulin secretion and Kv channel currents were examined by radioimmunoassay and patch-clamp technique, respectively...
December 2016: Peptides
https://www.readbyqxmd.com/read/27731415/role-of-the-ph-in-state-dependent-blockade-of-herg-currents
#9
Yibo Wang, Jiqing Guo, Laura L Perissinotti, James Lees-Miller, Guoqi Teng, Serdar Durdagi, Henry J Duff, Sergei Yu Noskov
Mutations that reduce inactivation of the voltage-gated Kv11.1 potassium channel (hERG) reduce binding for a number of blockers. State specific block of the inactivated state of hERG block may increase risks of drug-induced Torsade de pointes. In this study, molecular simulations of dofetilide binding to the previously developed and experimentally validated models of the hERG channel in open and open-inactivated states were combined with voltage-clamp experiments to unravel the mechanism(s) of state-dependent blockade...
October 12, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27684729/recording-gamma-band-oscillations-in-pedunculopontine-nucleus-neurons
#10
Francisco J Urbano, Brennon R Luster, Stasia D'Onofrio, Susan Mahaffey, Edgar Garcia-Rill
Synaptic efferents from the PPN are known to modulate the neuronal activity of several intralaminar thalamic regions (e.g., the centrolateral/parafascicular; Cl/Pf nucleus). The activation of either the PPN or Cl/Pf nuclei in vivo has been described to induce the arousal of the animal and an increment in gamma band activity in the cortical electroencephalogram (EEG). The cellular mechanisms for the generation of gamma band oscillations in Reticular Activating System (RAS) neurons are the same as those found to generate gamma band oscillations in other brains nuclei...
2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27679813/using-a-semi-automated-strategy-to-develop-multi-compartment-models-that-predict-biophysical-properties-of-interneuron-specific-3-is3-cells-in-hippocampus
#11
Alexandre Guet-McCreight, Olivier Camiré, Lisa Topolnik, Frances K Skinner
Determining how intrinsic cellular properties govern and modulate neuronal input-output processing is a critical endeavor for understanding microcircuit functions in the brain. However, lack of cellular specifics and nonlinear interactions prevent experiments alone from achieving this. Building and using cellular models is essential in these efforts. We focus on uncovering the intrinsic properties of mus musculus hippocampal type 3 interneuron-specific (IS3) cells, a cell type that makes GABAergic synapses onto specific interneuron types, but not pyramidal cells...
July 2016: ENeuro
https://www.readbyqxmd.com/read/27639255/nonlinear-effects-of-potassium-channel-blockers-on-endothelium-dependent-hyperpolarization
#12
H A Coleman, M Tare, H C Parkington
In a number of published studies on endothelium-dependent hyperpolarization and relaxation, the results of the effects of K(+) blockers have been difficult to interpret. When the effects of two blockers have been studied, often either blocker by itself had little effect, whereas the two blockers combined tended to abolish the responses. Explanations suggested in the literature include an unusual pharmacology of the K(+) channels, and possible blocker binding interactions. In contrast, when we applied the same blockers to segments of small blood vessels under voltage clamp, the blockers reduced the endothelium-dependent K(+) current in a linearly additive manner...
September 17, 2016: Acta Physiologica
https://www.readbyqxmd.com/read/27628569/different-effects-of-hypertension-and-age-on-the-function-of-large-conductance-calcium-and-voltage-activated-potassium-channels-in-human-mesentery-artery-smooth-muscle-cells
#13
Jun Cheng, Liang Mao, Jing Wen, Peng-Yun Li, Na Wang, Xiao-Qiu Tan, Xiao-Dong Zhang, Xiao-Rong Zeng, Liang Xu, Xian-Ming Xia, Dong Xia, Kai He, Song Su, Hui Yao, Yan Yang
BACKGROUND: Large-conductance calcium- and voltage-activated potassium channels (BKC a channels) play important roles in the maintenance of vascular tone, and their dysregulation is associated with abnormal vascular relaxation and contraction. We tested the changes in BKC a channel properties in patients at different ages to assess the effects of hypertension and aging on the functional changes of BKC a channels. METHODS AND RESULTS: Patch clamp was performed to detect the activities of BKC a channels in freshly isolated human mesenteric artery smooth muscle cells from younger patients (aged ≤45 years) without hypertension, older patients (aged ≥65 years) without hypertension, and older patients with hypertension...
September 2016: Journal of the American Heart Association
https://www.readbyqxmd.com/read/27625130/-study-on-the-electrophsiological-properties-in-the-stria-vascularis-pericytes-in-cochlear-of-guinea-pig
#14
Y H Liu, Y P Wang, Y Wang, K T Ma, J Q Si, L Li
OBJECTIVE: The purpose of this paper was to study the electrophysiological properties and the type of potassium channels on cell membrane in the stria vascularis pericytes in cochlear of guinea pig. METHODS: Firstly examined the expression of the stria vascularis pericytes by desmin, a marker of pericytes, in cochlear of guinea pig with immunofluorescent method. Using whole-cell patch clamp recording techniques to observe electrophysiological properties in the cochlear pericytes in stria vascularis of guinea pig...
August 7, 2016: Zhonghua Er Bi Yan Hou Tou Jing Wai Ke za Zhi, Chinese Journal of Otorhinolaryngology Head and Neck Surgery
https://www.readbyqxmd.com/read/27582084/kcna4-deficiency-leads-to-a-syndrome-of-abnormal-striatum-congenital-cataract-and-intellectual-disability
#15
Namik Kaya, Maysoon Alsagob, Maria Cristina D'Adamo, Albandary Al-Bakheet, Sonia Hasan, Maria Muccioli, Faten B Almutairi, Rawan Almass, Mazhor Aldosary, Dorota Monies, Osama M Mustafa, Banan Alyounes, Rosan Kenana, Jawaher Al-Zahrani, Eva Naim, Faisal S Binhumaid, Alya Qari, Fatema Almutairi, Brian Meyer, Timothy F Plageman, Mauro Pessia, Dilek Colak, Mohammed Al-Owain
BACKGROUND: Voltage-gated potassium channels are highly diverse proteins representing the most complex class of voltage-gated ion channels from structural and functional perspectives. Deficiency of these channels usually results in various human disorders. OBJECTIVES: To describe a novel autosomal recessive syndrome associated with KCNA4 deficiency leading to congenital cataract, abnormal striatum, intellectual disability and attention deficit hyperactivity disorder...
August 31, 2016: Journal of Medical Genetics
https://www.readbyqxmd.com/read/27562026/physiological-roles-of-kv2-channels-in-entorhinal-cortex-layer-ii-stellate-cells-revealed-by-guangxitoxin-1e
#16
Christoph Hönigsperger, Maximiliano J Nigro, Johan F Storm
KEY POINTS: Kv2 channels underlie delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Almost nothing is known about Kv2 channel functions in medial entorhinal cortex (mEC) neurons, which are involved in representing space, memory formation, epilepsy and dementia. Stellate cells in layer II of the mEC project to the hippocampus and are considered to be space-representing grid cells. We used the new Kv2 blocker Guangxitoxin-1E (GTx) to study Kv2 functions in these neurons...
August 26, 2016: Journal of Physiology
https://www.readbyqxmd.com/read/27530945/-composition-of-potassium-channels-in-normal-rat-coronary-smooth-muscle-cells-and-activation-effects-of-docosahexaenoic-acid
#17
L L Qian, R X Wang, M Q Sun, D Y Xia, X Tang, Y Ji, Y Wu, X Y Liu, S P Dang, Q Chai, T Lu
OBJECTIVE: To investigate the composition of potassium channels in normal rat coronary smooth muscle cells (CASMCs) and the activation effects of docosahexaenoic acid (DHA). METHODS: CASMCs were isolated by enzyme digestion.Effects of different types of potassium channel blockers and/or DHA on potassium channels currents were studied by whole-cell patch clamp technique. RESULTS: Potassium currents were significantly increased with 5 μmol/L DHA perfusion (P<0...
July 24, 2016: Zhonghua Xin Xue Guan Bing za Zhi
https://www.readbyqxmd.com/read/27511995/effect-of-ethanol-and-acetaldehyde-at-clinically-relevant-concentrations-on-atrial-inward-rectifier-potassium-current-ik1-separate-and-combined-effect
#18
Z Horakova, P Matejovic, M Pasek, J Hosek, M Simurdova, J Simurda, M Bebarova
Atrial fibrillation is the most common arrhythmia at alcohol consumption. Its pathogenesis is complex, at least partly related to changes of cardiac inward rectifier potassium currents including IK1. Both ethanol and acetaldehyde have been demonstrated to considerably modify IK1 in rat ventricular myocytes. However, analogical data on the atrial IK1 are lacking. The present study aimed to analyse IK1 changes induced by ethanol and acetyldehyde in atrial myocytes. The experiments were performed by the whole cell patch-clamp technique at 23 ± 1°C on enzymatically isolated rat and guinea-pig atrial myocytes as well as on expressed human Kir2...
June 2016: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
https://www.readbyqxmd.com/read/27443495/ph-sensitive-k-channel-trek-1-is-a-novel-target-in-pancreatic-cancer
#19
Daniel R P Sauter, Christiane E Sørensen, Markus Rapedius, Andrea Brüggemann, Ivana Novak
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and new therapeutic targets are urgently needed. One of the hallmarks of cancer is changed pH-homeostasis and potentially pH-sensors may play an important role in cancer cell behavior. Two-pore potassium channels (K2P) are pH-regulated channels that conduct a background K(+) current, which is involved in setting the plasma membrane potential (Vm). Some members of the K2P superfamily were reported as crucial players in driving tumor progression...
October 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27403141/effects-of-allocryptopine-on-outward-potassium-current-and-slow-delayed-rectifier-potassium-current-in-rabbit-myocardium
#20
Yi-Cheng Fu, Yu Zhang, Liu-Yang Tian, Nan Li, Xi Chen, Zhong-Qi Cai, Chao Zhu, Yang Li
OBJECTIVE: Allocryptopine (ALL) is an effective alkaloid of Corydalis decumbens (Thunb.) Pers. Papaveraceae and has proved to be anti-arrhythmic. The purpose of our study is to investigate the effects of ALL on transmural repolarizing ionic ingredients of outward potassium current (I to) and slow delayed rectifier potassium current (I Ks). METHODS: The monophasic action potential (MAP) technique was used to record the MAP duration of the epicardium (Epi), myocardium (M) and endocardium (Endo) of the rabbit heart and the whole cell patch clamp was used to record I to and I Ks in cardiomyocytes of Epi, M and Endo layers that were isolated from rabbit ventricles...
May 2016: Journal of Geriatric Cardiology: JGC
keyword
keyword
16180
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"