keyword
MENU ▼
Read by QxMD icon Read
search

Single channel patch clamp

keyword
https://www.readbyqxmd.com/read/29335317/reduced-n-type-ca2-channels-in-atrioventricular-ganglion-neurons-are-involved-in-ventricular-arrhythmogenesis
#1
Dongze Zhang, Huiyin Tu, Liang Cao, Hong Zheng, Robert L Muelleman, Michael C Wadman, Yu-Long Li
BACKGROUND: Attenuated cardiac vagal activity is associated with ventricular arrhythmogenesis and related mortality in patients with chronic heart failure. Our recent study has shown that expression of N-type Ca2+ channel α-subunits (Cav2.2-α) and N-type Ca2+ currents are reduced in intracardiac ganglion neurons from rats with chronic heart failure. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Ventricular myocardium receives projection of neuronal terminals only from the AVG...
January 15, 2018: Journal of the American Heart Association
https://www.readbyqxmd.com/read/29324898/the-etomidate-analog-et-26-hcl-retains-superior-myocardial-performance-comparisons-with-etomidate-in-vivo-and-in-vitro
#2
Xingxing Liu, Haibo Song, Jun Yang, Cheng Zhou, Yi Kang, Linghui Yang, Jin Liu, Wensheng Zhang
OBJECTIVE: (R)-2-methoxyethyl1-(1-phenylethyl)-1H-imidazole-5-carboxylate hydrochloride (ET-26 HCl) is a novel etomidate analogue. The purpose of this study was to characterize whether ET-26 HCl could retain the superior myocardial performance of etomidate in vivo and in vitro. METHODS: In vivo, the influence of ET-26 HCl and etomidate on the cardiac function of dogs was confirmed using echocardiography and electrocardiogram. In vitro, a Langendorff preparation was used to examine direct myocardial performance in isolated rat hearts, and a whole-cell patch-clamp technique was used to study effects on the human ether-a-go-go-related gene (hERG) channel...
2018: PloS One
https://www.readbyqxmd.com/read/29318594/partial-rescue-of-f508del-cftr-channel-gating-with-modest-improvement-of-protein-processing-but-not-stability-by-a-dual-acting-small-molecule
#3
Jia Liu, Hermann Bihler, Carlos M Farinha, Nikhil T Awatade, Ana M Romão, Dayna Mercadante, Yi Cheng, Isaac Musisi, Walailak Jantarajit, Yiting Wang, Zhiwei Cai, Margarida D Amaral, Martin Mense, David N Sheppard
BACKGROUND AND PURPOSE: Rescue of F508del-cystic fibrosis transmembrane conductance regulator (CFTR), the most common cystic fibrosis (CF) mutation, requires small molecules that overcome protein processing, stability and channel gating defects. Here, we investigate F508del-CFTR rescue by CFFT-004 (from WO2010/068863), a small molecule designed to independently correct protein processing and channel gating defects. EXPERIMENTAL APPROACH: Using CFTR-expressing recombinant cells and CF patient-derived bronchial epithelial cells, we studied CFTR expression by Western blotting and channel gating and stability with the patch-clamp and Ussing chamber techniques...
January 10, 2018: British Journal of Pharmacology
https://www.readbyqxmd.com/read/29298877/molecular-basis-for-potentiation-of-cx36-gap-junction-channel-conductance-by-n-alcohols-and-general-anesthetics
#4
Vytautas Raškevičius, Vaidas Jotautis, Lina Rimkutė, Alina Marandykina, Mintautė Kazokaitė, Visvaldas Kairys, Vytenis Arvydas Skeberdis
In our recent study, we have demonstrated that short carbon chain n -alcohols (up to octanol) stimulated while long carbon chain n -alcohols inhibited the conductance of connexin 36 (Cx36) gap junction (GJ) channels. In contrast, GJ channels composed of other types of Cxs all were inhibited by n -alcohols independently on their carbon chain length. To identify the putative structural domains of Cx36, responsible for the dual effect of n -alcohols, we performed structural modeling of Cx36 protein docking with hexanol and isoflurane that stimulated as well as nonanol and carbenoxolone that inhibited the conductance of Cx36 GJs and revealed their multiple common docking sites and a single pocket accessible only to hexanol and isoflurane...
January 3, 2018: Bioscience Reports
https://www.readbyqxmd.com/read/29283181/loss-of-constitutive-functional-%C3%AE-aminobutyric-acid-type-a-b-receptor-crosstalk-in-layer-5-pyramidal-neurons-of-human-epileptic-temporal-cortex
#5
Katiuscia Martinello, Miriam Sciaccaluga, Roberta Morace, Addolorata Mascia, Antonietta Arcella, Vincenzo Esposito, Sergio Fucile
OBJECTIVE: γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in adult central nervous system, and profound alterations of GABA receptor functions are linked to temporal lobe epilepsy (TLE). Here we describe the functional relationships between GABA receptors type B (GABAB R) and type A (GABAA R) in human temporal cortex and how TLE affects this aspect of GABAergic signaling. METHODS: Miniature inhibitory postsynaptic currents (mIPSCs) were recorded by patch-clamp techniques from human L5 pyramidal neurons in slices from temporal cortex tissue obtained from surgery...
December 28, 2017: Epilepsia
https://www.readbyqxmd.com/read/29259649/chloroform-extract-of-artemisia-annua-l-relaxes-mouse-airway-smooth-muscle
#6
Jun Huang, Li-Qun Ma, Yongle Yang, Nana Wen, Wan Zhou, Congli Cai, Qing-Hua Liu, Jinhua Shen
Artemisia annua L. belongs to the Asteraceae family, which is indigenous to China. It has valuable pharmacological properties, such as antimalarial, anti-inflammatory, and anticancer properties. However, whether it possesses antiasthma properties is unknown. In the current study, chloroform extract of Artemisia annua L. (CEAA) was prepared, and we found that CEAA completely eliminated acetylcholine (ACh) or high K+-elicited (80 mM) contractions of mouse tracheal rings (TRs). Patch-clamp technique and ion channel blockers were employed to explore the underlying mechanisms of the relaxant effect of CEAA...
2017: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/29251644/pharmacodynamics-and-pharmacokinetics-of-lidocaine-in-a-rodent-model-of-diabetic-neuropathy
#7
Werner Ten Hoope, Markus W Hollmann, Kora de Bruin, Hein J Verberne, Arie O Verkerk, Hanno L Tan, Camiel Verhamme, Janneke Horn, Marcel Rigaud, Susanne Picardi, Philipp Lirk
BACKGROUND: Clinical and experimental data show that peripheral nerve blocks last longer in the presence of diabetic neuropathy. This may occur because diabetic nerve fibers are more sensitive to local anesthetics or because the local anesthetic concentration decreases more slowly in the diabetic nerve. The aim of this study was to investigate both hypotheses in a rodent model of neuropathy secondary to type 2 diabetes. METHODS: We performed a series of sciatic nerve block experiments in 25 Zucker Diabetic Fatty rats aged 20 weeks with a neuropathy component confirmed by neurophysiology and control rats...
December 15, 2017: Anesthesiology
https://www.readbyqxmd.com/read/29242169/c60-fullerenes-disrupt-cellular-signalling-leading-to-trpc4-and-trpc6-channels-opening-by-the-activation-of-muscarinic-receptors-and-g-proteins-in-small-intestinal-smooth-muscles
#8
Dariia O Dryn, Mariia I Melnyk, Lina T Al Kury, Yuriy I Prylutskyy, Uwe Ritter, Alexander V Zholos
The effect of water-soluble pristine C60 fullerene nanoparticles (C60NPs) on receptor-operated cation channels formed by TRPC4/C6 proteins in ileal smooth muscle cells was investigated for the first time. Activation of these channels subsequent to acetylcholine binding to the expressed in these cells M2 and M3 muscarinic receptors represents the key event in the parasympathetic control of gastrointestinal smooth muscle motility and cholinergic excitation-contraction coupling. Experiments were performed on single collagenase-dispersed mouse ileal myocytes using patch-clamp techniques with symmetrical 125mM Cs+ solutions and [Ca2+]i 'clamped' at 100nM in order to isolate the muscarinic cation current (mICAT)...
December 11, 2017: Cellular Signalling
https://www.readbyqxmd.com/read/29214635/kv4-2-channel-activity-controls-intrinsic-firing-dynamics-of-arcuate-kisspeptin-neurons
#9
Philipe R F Mendonça, Victoria Kyle, Shel-Hwa Yeo, William H Colledge, Hugh P C Robinson
Kisspeptin neurons in the hypothalamus are critically involved in reproductive function, via their effect on GnRH neuron activity and consequent gonadotropin release. Kisspeptin neurons show an intrinsic irregularity of firing, but the mechanism of this remains unclear. To address this, we carried out targeted whole-cell patch-clamp recordings of kisspeptin neurons in the arcuate nucleus (Kiss1Arc ), in brain slices isolated from adult male Kiss-Cre:tdTomato mice. Cells fired irregularly in response to constant current stimuli, with a wide range of spike time variability, and prominent subthreshold voltage fluctuations...
December 6, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29211992/fluctuation-analysis-in-nonstationary-conditions-single-ca2-channel-current-in-pyramidal-neurons
#10
Christian Scheppach, Hugh P C Robinson
Fluctuation analysis is a method that allows measurement of the single-channel current of ion channels even when it is too small to be resolved directly with the patch-clamp technique. This is the case for voltage-gated calcium channels. They are present in all mammalian central neurons, controlling presynaptic release of transmitter, postsynaptic signaling, and synaptic integration. The amplitudes of their single-channel currents in a physiological concentration of extracellular calcium, however, are small and not well determined...
December 5, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29172153/ajmaline-blocks-ina-and-ikr-without-eliciting-differences-between-brugada-syndrome-patient-and-control-human-pluripotent-stem-cell-derived-cardiac-clusters
#11
Duncan C Miller, Stephen C Harmer, Ariel Poliandri, Muriel Nobles, Elizabeth C Edwards, James S Ware, Tyson V Sharp, Tristan R McKay, Leo Dunkel, Pier D Lambiase, Andrew Tinker
The class Ia anti-arrhythmic drug ajmaline is used clinically to unmask latent type I ECG in Brugada syndrome (BrS) patients, although its mode of action is poorly characterised. Our aims were to identify ajmaline's mode of action in human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs), and establish a simple BrS hiPSC platform to test whether differences in ajmaline response could be determined between BrS patients and controls. Control hiPSCs were differentiated into spontaneously contracting cardiac clusters...
November 7, 2017: Stem Cell Research
https://www.readbyqxmd.com/read/29163046/rim-binding-protein-2-promotes-a-large-number-of-cav1-3-ca-2-channels-and-contributes-to-fast-synaptic-vesicle-replenishment-at-hair-cell-active-zones
#12
Stefanie Krinner, Tanvi Butola, SangYong Jung, Carolin Wichmann, Tobias Moser
Ribbon synapses of inner hair cells (IHCs) mediate high rates of synchronous exocytosis to indefatigably track the stimulating sound with sub-millisecond precision. The sophisticated molecular machinery of the inner hair cell active zone realizes this impressive performance by enabling a large number of synaptic voltage-gated CaV1.3 Ca(2+)-channels, their tight coupling to synaptic vesicles (SVs) and fast replenishment of fusion competent SVs. Here we studied the role of RIM-binding protein 2 (RIM-BP2)-a multidomain cytomatrix protein known to directly interact with Rab3 interacting molecules (RIMs), bassoon and CaV1...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/29162702/structural-basis-for-the-antiarrhythmic-blockade-of-a-potassium-channel-with-a-small-molecule
#13
Yoshio Takemoto, Diana P Slough, Gretchen Meinke, Christopher Katnik, Zachary A Graziano, Bojjibabu Chidipi, Michelle Reiser, Mohammed M Alhadidy, Rafael Ramirez, Oscar Salvador-Montañés, Steven Ennis, Guadalupe Guerrero-Serna, Marian Haburcak, Carl Diehl, Javier Cuevas, Jose Jalife, Andrew Bohm, Yu-Shan Lin, Sami F Noujaim
The acetylcholine-activated inward rectifier potassium current (IKACh) is constitutively active in persistent atrial fibrillation (AF). We tested the hypothesis that the blocking of IKACh with the small molecule chloroquine terminates persistent AF. We used a sheep model of tachypacing-induced, persistent AF, molecular modeling, electrophysiology, and structural biology approaches. The 50% inhibition/inhibitory concentration of IKACh block with chloroquine, measured by patch clamp, was 1 μM. In optical mapping of sheep hearts with persistent AF, 1 μM chloroquine restored sinus rhythm...
November 21, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/29158021/gold-nanoparticles-potentiate-cav-channel-currents-in-rat-tail-artery-myocytes
#14
Fabio Fusi, Giampietro Sgaragli, Massimo Valoti
This study was designed to unveil effects of 5-nm sized, polyvinylpyrrolidone-coated gold nanoparticles (AuNPs) on vascular CaV1.2 and CaV3.1 channels. Ba(2+) currents through both channels (IBa1.2 and IBa3.1) were recorded in single myocytes isolated from the rat tail main artery by means of the whole-cell patch-clamp method. AuNPs increased IBa1.2 and IBa3.1 amplitude in a concentration- and Vh-dependent manner. Neither the voltage dependence of inactivation and activation curves nor inactivation and activation kinetics were affected by AuNPs...
November 17, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/29150838/gi-530159-a-novel-selective-mechano-sensitive-k2p-channel-opener-reduces-rat-dorsal-root-ganglion-drg-neuron-excitability
#15
Alexandre J C Loucif, Pierre-Philippe Saintot, Jia Liu, Brett M Antonio, Shannon G Zellmer, Katrina Yoger, Emma L Veale, Anna Wilbrey, Kiyoyuki Omoto, Lishuang Cao, Alex Gutteridge, Neil A Castle, Edward B Stevens, Alistair Mathie
BACKGROUND AND PURPOSE: TREK two pore domain potassium channels play a critical role in regulating the excitability of somatosensory nociceptive neurons and are important mediators of pain perception. An understanding of the roles of TREK channels in pain perception and, indeed, in other pathophysiological conditions, has been severely hampered by the lack of potent and/or selective activators and inhibitors. In this study we describe a new, selective opener of TREK channels, GI-530159 (4,4'-(Hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline)...
November 18, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/29143966/drug-interaction-at-herg-channel-in-vitro-assessment-of-the-electrophysiological-consequences-of-drug-combinations-and-comparison-against-theoretical-models
#16
Barbara Wiśniowska, Bartosz Lisowski, Magdalena Kulig, Sebastian Polak
Drugs carry a proarrhythmic risk, which gets even greater when they are used in combination. In vitro assessment of the proarrhythmic potential of drugs is limited to one compound and thus neglects the potential of drug-drug interactions, including those involving active metabolites. Here we present the results of an in vitro study of potential drug-drug interactions at the level of the hERG channel for the combination of up to three compounds: loratadine, desloratadine and ketoconazole. Experiments were performed at room temperature on an automated patch-clamp device CytoPatch 2, with the use of heterogeneously, stably transfected HEK cells...
November 16, 2017: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/29134279/dietary-k-and-cl-independently-regulate-basolateral-conductance-in-principal-and-intercalated-cells-of-the-collecting-duct
#17
Viktor N Tomilin, Oleg Zaika, Arohan R Subramanya, Oleh Pochynyuk
The renal collecting duct contains two distinct cell types, principal and intercalated cells, expressing potassium Kir4.1/5.1 (KCNJ10/16) and chloride ClC-K2 (ClC-Kb in humans) channels on their basolateral membrane, respectively. Both channels are thought to play important roles in controlling systemic water-electrolyte balance and blood pressure. However, little is known about mechanisms regulating activity of Kir4.1/5.1 and ClC-K2/b. Here, we employed patch clamp analysis at the single channel and whole cell levels in freshly isolated mouse collecting ducts to investigate regulation of Kir4...
November 13, 2017: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/29118035/single-channel-analysis-of-isoflurane-and-ethanol-enhancement-of-taurine-activated-glycine-receptors
#18
Dean Kirson, Jelena Todorovic, S John Mihic
The amino acid taurine is an endogenous ligand acting on glycine receptors and is released by astrocytes in many brain regions, such as the nucleus accumbens and prefrontal cortex. Taurine is a partial agonist with an efficacy significantly lower than that of glycine. Allosteric modulators such as ethanol and isoflurane produce leftward shifts of glycine concentration-response curves but have no effects at saturating glycine concentrations. In contrast, in whole-cell electrophysiology studies these modulators increase the effects of saturating taurine concentrations...
November 8, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/29107716/pacsin-2-is-required-for-the-maintenance-of-a-normal-cardiac-function-in-the-developing-mouse-heart
#19
Judith Semmler, Jan Kormann, Sureshkumar Perumal Srinivasan, Annette Köster, Daniel Sälzer, Michael Reppel, Jürgen Hescheler, Markus Plomann, Filomain Nguemo
The Pacsin proteins (Pacsin 1, 2 and 3) play an important role in intracellular trafficking and thereby signal transduction in many cells types. This study was designed to examine the role of Pacsin 2 in cardiac development and function. We investigated the development and electrophysiological properties of Pacsin 2 knockout (P2KO) hearts and single cardiomyocytes isolated from 11.5 and 15.5days old fetal mice. Immunofluorescence experiments confirmed the lack of Pacsin 2 protein expression in P2KO cardiac myocytes in comparison to wildtype (WT)...
October 28, 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/29090695/on-the-selectivity-of-the-nachbac-channel-an-integrated-computational-and-experimental-analysis-of-sodium-and-calcium-permeation
#20
Carlo Guardiani, Olena A Fedorenko, Stephen K Roberts, Igor A Khovanov
Ion channel selectivity is essential for their function, yet the molecular basis of a channel's ability to select between ions is still rather controversial. In this work, using a combination of molecular dynamics simulations and electrophysiological current measurements we analyze the ability of the NaChBac channel to discriminate between calcium and sodium. Our simulations show that a single calcium ion can access the Selectivity Filter (SF) interacting so strongly with the glutamate ring so as to remain blocked inside...
November 1, 2017: Physical Chemistry Chemical Physics: PCCP
keyword
keyword
35644
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"