Read by QxMD icon Read

potassium channel

Lijiang Ma, Wendy K Chung
Group 1 pulmonary hypertension or pulmonary arterial hypertension (PAH) is a rare disease characterized by proliferation and occlusion of small pulmonary arterioles, leading to progressive elevation of pulmonary artery pressure and pulmonary vascular resistance, and right ventricular failure. Historically it has been associated with a high mortality rate, although over the last decade, treatment has improved survival. PAH includes idiopathic PAH (IPAH), heritable PAH (HPAH), and PAH associated with certain medical conditions...
October 22, 2016: Journal of Pathology
Wilfried Dinh, Barbara Albrecht-Küpper, Mihai Gheorghiade, Adriaan A Voors, Michael van der Laan, Hani N Sabbah
Adenosine exerts a variety of physiological effects by binding to cell surface G-protein-coupled receptor subtypes, namely, A1, A2a, A2b, and A3. The central physiological role of adenosine is to preclude tissue injury and promote repair in response to stress. In the heart, adenosine acts as a cytoprotective modulator, linking cardiac function to metabolic demand predominantly via activation of adenosine A1 receptors (A1Rs), which leads to inhibition of adenylate cyclase activity, modulation of protein kinase C, and opening of ATP-sensitive potassium channels...
October 22, 2016: Handbook of Experimental Pharmacology
Derek Garden, Arianna Rinaldi, Matthew F Nolan
The inferior olive plays a critical role in motor coordination and learning by integrating diverse afferent signals to generate climbing fibre inputs to the cerebellar cortex. While it is well established that climbing fibre signals are important for motor coordination, the mechanisms by which neurones in the inferior olive integrate synaptic inputs and the roles of particular ion channels are unclear. Here, we test the hypothesis that neurones in the inferior olive actively integrate glutamatergic synaptic inputs...
October 21, 2016: Journal of Physiology
Sha-Sha Huang, Qiu-Bing Zhang, Qing-Yan Yuan, Si-Li He, Yuan-Ming Zhang
INTRODUCTION: Activation of T lymphocytes, for which potassium channels are essential, is involved in the development of hypertension. In this study, we explored the inhibitory effects of telmisartan on the culture and proliferation of and Kv1.3 potassium channel expression in peripheral blood CD4(+) T lymphocytes derived from Xinjiang Kazakh patients with hypertension. METHODS: CD4(+) T-cell samples from hypertensive Kazakh patients and healthy Kazakh people were divided into healthy control, case control, telmisartan, and 4-aminopytidine groups...
October 2016: Journal of the Renin-angiotensin-aldosterone System: JRAAS
Stefano Fiorucci, Angela Zampella, Giuseppe Cirino, Mariarosaria Bucci, Eleonora Distrutti
Bile acids are end product of cholesterol metabolism generated in the liver and released in the intestine. In addition to their role in nutrient absorption, bile acids are increasingly recognized as regulatory signals which exert their function beyond the intestine by activating a network of membrane and nuclear receptors. The best characterized of these bile acid activated receptors, GPBAR1 (also known as TGR5) and the Farnesosid-x-receptor (FXR) have also been detected in the vascular system and their activation mediate the vasodilatory effects of bile acids in the systemic and splanchnic circulation...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Fahima Syeda, Andrew P Holmes, Ting Y Yu, Samantha Tull, Stefan Michael Kuhlmann, Davor Pavlovic, Daniel Betney, Genna Riley, Jan P Kucera, Florian Jousset, Joris R de Groot, Stephan Rohr, Nigel A Brown, Larissa Fabritz, Paulus Kirchhof
BACKGROUND: Antiarrhythmic drugs are widely used to treat patients with atrial fibrillation (AF), but the mechanisms conveying their variable effectiveness are not known. Recent data suggested that paired like homeodomain-2 transcription factor (PITX2) might play an important role in regulating gene expression and electrical function of the adult left atrium (LA). OBJECTIVES: After determining LA PITX2 expression in AF patients requiring rhythm control therapy, the authors assessed the effects of Pitx2c on LA electrophysiology and the effect of antiarrhythmic drugs...
October 25, 2016: Journal of the American College of Cardiology
Rajeev B Tajhya, Xueyou Hu, Mark R Tanner, Redwan Huq, Natee Kongchan, Joel R Neilson, George G Rodney, Frank T Horrigan, Lubov T Timchenko, Christine Beeton
Myoblasts are mononucleated precursors of myofibers; they persist in mature skeletal muscles for growth and regeneration post injury. During myotonic dystrophy type 1 (DM1), a complex autosomal-dominant neuromuscular disease, the differentiation of skeletal myoblasts into functional myotubes is impaired, resulting in muscle wasting and weakness. The mechanisms leading to this altered differentiation are not fully understood. Here, we demonstrate that the calcium- and voltage-dependent potassium channel, KCa1...
October 20, 2016: Cell Death & Disease
Takehito Kondo, Ichiro Hisatome, Shouichi Yoshimura, Endang Mahati, Tomomi Notsu, Peili Li, Kazuhiko Iitsuka, Masaru Kato, Kazuyoshi Ogura, Junichiro Miake, Takeshi Aiba, Wataru Shimizu, Yasutaka Kurata, Shinji Sakata, Naoe Nakasone, Haruaki Ninomiya, Akira Nakai, Katsumi Higaki, Yasushi Kawata, Yasuaki Shirayoshi, Akio Yoshida, Kazuhiro Yamamoto
BACKGROUND: The human ether-a-go-go-related gene (HERG) encodes the α-subunit of rapidly activating delayed-rectifier potassium channels. Mutations in this gene cause long QT syndrome type 2 (LQT2). In most cases, mutations reduce the stability of the channel protein, which can be restored by heat shock (HS). METHODS: We identified the novel mutant A78T-HERG in a patient with LQT2. The purpose of the current study was to characterize this mutant protein and test whether HS and heat shock factors (HSFs) could stabilize the mutant protein...
October 2016: Journal of Arrhythmia
Ricardo Rodrigues Figueiredo, Andréia Aparecida Azevedo, Norma De Oliveira Penido
INTRODUCTION: Tinnitus is the perception of noise in the absence of an external source and is considered by most authors as a multifactorial symptom. A systematic review concerning the association of tinnitus and systemic arterial hypertension retrieved suggestions of a positive association, but the articles included failed to perform a detailed analysis on the theme. PURPOSE: To analyze the presence of arterial hypertension in tinnitus and non-tinnitus patients, to analyze differences between tinnitus impact and psychoacoustic measurements in hypertensive and normotensive patients, and to evaluate the association between the presence of tinnitus and the diverse antihypertensive drugs employed...
2016: Frontiers in Neurology
Shixiao Zhang, Zan Guo, Shijie Yang, Huijuan Ma, Congrui Fu, Sheng Wang, Yi Zhang, Yixian Liu, Jie Hu
OBJECTIVE: Providing adequate protection against cerebral ischemia remains an unrealized goal. The present study was aimed at testing whether chronic intermittent hypobaric hypoxia (CIHH) would have protective effects against cerebral ischemia and investigating the potential role of mitochondrial membrane ATP-sensitive potassium channel (mitoKATP) in this effect. METHODS: Ischemia was induced in rats by occlusion of bilateral common carotid arteries for 8min on day 2 after bilateral vertebral arteries were permanently electrocauterized and CIHH was simulated in a hypoxic chamber...
October 16, 2016: Neuroscience Letters
Béla Voß, Reinhard Seifert, U Benjamin Kaupp, Helmut Grubmüller
Ligand-protein binding processes are essential in biological systems. A well-studied system is the binding of cyclic adenosine monophosphate to the cyclic nucleotide binding domain of the bacterial potassium channel MloK1. Strikingly, the measured on-rate for cyclic adenosine monophosphate binding is two orders of magnitude slower than a simple Smoluchowski diffusion model would suggest. To resolve this discrepancy and to characterize the ligand-binding path in structural and energetic terms, we calculated 1100 ligand-binding molecular dynamics trajectories and tested two scenarios: In the first scenario, the ligand transiently binds to the protein surface and then diffuses along the surface into the binding site...
October 18, 2016: Biophysical Journal
Gilles Maussion, Cristiana Cruceanu, Jill A Rosenfeld, Scott C Bell, Fabrice Jollant, Jin Szatkiewicz, Ryan L Collins, Carrie Hanscom, Ilaria Kolobova, Nicolas Menjot de Champfleur, Ian Blumenthal, Colby Chiang, Vanessa Ota, Christina Hultman, Colm O'Dushlaine, Steve McCarroll, Martin Alda, Sebastien Jacquemont, Zehra Ordulu, Christian R Marshall, Melissa T Carter, Lisa G Shaffer, Pamela Sklar, Santhosh Girirajan, Cynthia C Morton, James F Gusella, Gustavo Turecki, Dimitri J Stavropoulos, Patrick F Sullivan, Stephen W Scherer, Michael E Talkowski, Carl Ernst
We performed whole-genome sequencing on an individual from a family with variable psychiatric phenotypes that had a sensory processing disorder, apraxia, and autism. The proband harbored a maternally inherited balanced translocation (46,XY,t(11;14)(p12;p12)mat) that disrupted LRRC4C, a member of the highly specialized netrin G family of axon guidance molecules. The proband also inherited a paternally derived chromosomal inversion that disrupted DPP6, a potassium channel interacting protein. Copy Number (CN) analysis in 14,077 cases with neurodevelopmental disorders and 8,960 control subjects revealed that 60% of cases with exonic deletions in LRRC4C had a second clinically recognizable syndrome associated with variable clinical phenotypes, including 16p11...
October 19, 2016: American Journal of Medical Genetics. Part A
Zhenzhen Yan, Bin Hu, Zhigang Huang, Ling Zhong, Xiying Guo, Anxi Weng, Feng Xiao, Wenping Zeng, Yan Zhang, Jiuping Ding, Panpan Hou
Large-conductance Ca2+- and voltage-activated potassium (BK) channels are widely expressed in tissues. As a voltage and calcium sensor, BK channels play significant roles in regulating the action potential frequency, neurotransmitter release, and smooth muscle contraction. After associating with the auxiliary β2 subunit, mammalian BK(β2) channels (mouse or human Slo1/β2) exhibit enhanced activation and complete inactivation. However, how the β2 subunit modulates the Drosophila Slo1 channel remains elusive...
2016: PloS One
Andreas Reichenbach, Andreas Bringmann
Müller glia, the principal macroglia of the retina, express diverse subtypes of adenosine and metabotropic purinergic (P2Y) receptors. Müller cells of several species, including man, also express ionotropic P2X7 receptors. ATP is liberated from Müller cells after activation of metabotropic glutamate receptors and during osmotic and mechanical induction of membrane stretch; adenosine is released through equilibrative nucleoside transporters. Müller cell-derived purines modulate the neuronal activity and have autocrine effects, for example, induction of glial calcium waves and regulation of the cellular volume...
October 2016: Journal of Ocular Pharmacology and Therapeutics
Amichai Gutgold, David J Gross, Benjamin Glaser, Auryan Szalat
CONTEXT: Hypoglycemia is a rare event in healthy adults, and the differential diagnosis includes many diseases some of which are rare and easily missed. Description of the case: A 20 year-old male military paramedic was referred to our Emergency Department for the investigation of recurrent hypoglycemia episodes during the last months. Factitious hypoglycemia was excluded and organic hyperinsulinemic hypoglycemia was diagnosed by prolonged fast. Imaging studies (endoscopic ultrasound and triple-phase computed tomography) were normal...
October 18, 2016: Journal of Clinical Endocrinology and Metabolism
Ge Su, Min Zhang, Wen Si, Zhan-Ting Li, Jun-Li Hou
Three unimolecular peptide channels have been designed and prepared by using the β-helical conformation of gramicidin A (gA). The new peptides bear one to three NH3(+) groups at the N-end and one to three CO2(-) groups at the C-end. These zwitterionic peptides were inserted into lipid bilayers in an orientation-selective manner. Conductance experiments on planar lipid bilayers showed that this orientation bias could lead to observable directional K(+) transport under multi-channel conditions. This directional transport behavior can further cause the generation of a current across a planar bilayer without applying a voltage...
October 18, 2016: Angewandte Chemie
Satoshi Umemura
Primary aldosteronism (PA) is a heterogeneous group of disorders including both sporadic and familial forms (familial hyperaldosteronism type I, II and III). PA is the most frequent endocrine cause of secondary hypertension and associated with a higher rate of cardiovascular complications, compared with essential hypertension.Here I review the recent progress in understanding of the genetic and molecular mechanisms leading to autonomous aldosterone production in PA.Systematic screening detects primary aldosteronism in 5 to 10% of all patients with hypertension and in approximately 20% of patients with resistant hypertension...
September 2016: Journal of Hypertension
Pasquale Striano, Vincenzo Belcastro, Antonietta Coppola, Carlo Minetti, Salvatore Striano
INTRODUCTION: Despite optimal medical treatment, up to 30% of patients with epilepsy continue to experience recurrent seizures, and the challenge for new more efficacious and better-tolerated drugs is continuing. New antiepileptic drugs include the evolution of preexisting drugs and new compounds identified through the investigation of additional molecular targets, such as SV2A synaptic vesicle protein, voltage-gated potassium channels, ionotropic and metabotropic glutamate receptors, and gap junctions...
October 5, 2016: Clinical Neuropharmacology
Hung X Nguyen, Robert D Kirkton, Nenad Bursac
The ability to directly enhance electrical excitability of human cells is hampered by the lack of methods to efficiently overexpress large mammalian voltage-gated sodium channels (VGSC). Here we describe the use of small prokaryotic sodium channels (BacNav) to create de novo excitable human tissues and augment impaired action potential conduction in vitro. Lentiviral co-expression of specific BacNav orthologues, an inward-rectifying potassium channel, and connexin-43 in primary human fibroblasts from the heart, skin or brain yields actively conducting cells with customizable electrophysiological phenotypes...
October 18, 2016: Nature Communications
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
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"