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https://www.readbyqxmd.com/read/28719725/effects-of-eupatilin-on-the-contractility-of-corpus-cavernosal-smooth-muscle-through-nitric-oxide-independent-pathways
#1
S H Choo, S W Lee, M R Chae, S J Kang, H H Sung, D H Han, J N Chun, J K Park, C Y Kim, H K Kim, I So
Eupatilin (5,7-dihydroxy-3,4,6-trimethoxyflavone) is one of the main compounds present in Artemisia species. Eupatilin has both antioxidative and anti-inflammatory properties and a relaxation effect on vascular contraction regardless of endothelial function. We evaluated the relaxant effects of eupatilin on the corpus cavernosum (CC) of rabbits and the underlying mechanisms of its activity in human corpus cavernosum smooth muscle (CCSM) cells. Isolated rabbit CC strips were mounted in an organ bath system. A conventional whole-cell patch clamp technique was used to measure activation of calcium-sensitive K(+) -channel currents in human CCSM cells...
July 18, 2017: Andrology
https://www.readbyqxmd.com/read/28716724/the-ppar%C3%AE-activator-fenofibrate-inhibits-voltage-dependent-k-channels-in-rabbit-coronary-arterial-smooth-muscle-cells
#2
Hongliang Li, Sung Eun Shin, Mi Seon Seo, Jin Ryeol An, Won-Kyo Jung, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Hyoweon Bang, Young Min Bae, Amy L Firth, Il-Whan Choi, Won Sun Park
We examined the effects of the PPARα activator fenofibrate on voltage-dependent K(+) (Kv) channels using a patch clamp technique in native rabbit coronary arterial smooth muscle cells. Kv current was inhibited by application of fenofibrate in a concentration-dependent manner, with an apparent IC50 value of 6.39 ± 0.53μM and a slope value (Hill coefficient) of 1.63 ± 0.10. Fenofibrate accelerated the decay rate of Kv channel inactivation. The rate constants of association and dissociation for fenofibrate were 0...
July 14, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28714121/acetylcholine-dependent-upregulation-of-task-1-channels-in-thalamic-interneurons-by-a-smooth-muscle-like-signalling-pathway
#3
Michael Leist, Susanne Rinné, Maia Datunashvili, Ania Aissaoui, Hans-Christian Pape, Niels Decher, Sven G Meuth, Thomas Budde
The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay (TC) neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism...
July 17, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28714095/effect-of-dietary-salt-intake-on-epithelial-na-channels-enac-in-vasopressin-magnocellular-neurosecretory-neurons-in-the-rat-supraoptic-nucleus
#4
Kaustubh Sharma, Masudul Haque, Richard Guidry, Yoichi Ueta, Ryoichi Teruyama
All three epithelial Na(+) channel (ENaC) subunits (α, β, and γ) were located in vasopressin (VP) magnocellular neurons in the hypothalamic supraoptic (SON) and paraventricular nuclei. Our previous study demonstrated that ENaC mediates a Na(+) leak current that affects the steady state membrane potential in VP neurons. In the present study, we evaluated the effect of dietary salt intake on ENaC regulation and activity in VP neurons. High dietary salt intake for 7 days caused an increase in expression of β- and γENaC subunits in the SON and the translocation of αENaC immunoreactivity towards the plasma membrane...
July 17, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28714070/a-reduction-in-sk-channels-contributes-to-increased-activity-of-hypothalamic-magnocellular-neurons-during-heart-failure
#5
H C Ferreira-Neto, V Biancardi, J E Stern
Small conductance Ca(2+) -activated K(+) channels (SK) play an important role in regulating MNCs activity and hormone release from the posterior pituitary. Moreover, an enhanced SK activity contributes to MNCs' adaptive responses to a physiological challenge, such as lactation. Still, whether changes in SK function/expression contribute to exacerbated MNCs activity during diseases like heart failure (HF), remains unknown. Here, we used a combination of patch-clamp electrophysiology, confocal Ca(2+) imaging and molecular biology in a rat model of ischemic HF...
July 17, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28711966/modified-single-patch-technique-versus-two-patch-technique-for-the-repair-of-complete-atrioventricular-septal-defect-a-meta-analysis
#6
Dongxu Li, Qiang Fan, Tomoyuki Iwase, Yasutaka Hirata, Qi An
Technical selection for surgical repair of complete atrioventricular septal defect (CAVSD) still remains controversial. This meta-analysis aimed to compare the modified single-patch (MP) technique with the two-patch (TP) technique for patients with CAVSD. Relevant studies comparing the MP technique with the TP technique were identified through a literature search using MEDLINE, EMBASE, Google Scholar, Cochrane Library, and the China National Knowledge Infrastructure databases. The variables were ventricular septal defect (VSD) size, cardiopulmonary bypass (CBP) time, aortic cross-clamp (ACC) time, intensive care unit stay, hospital stay, and other outcomes involving mortality, left ventricular outflow tract obstruction, atrioventricular valve regurgitation, residual septal shunt, atrioventricular block, and reoperation...
July 15, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28711908/the-2-aminoethoxydiphenyl-borate-analog-dpb161-blocks-store-operated-ca2-entry-in-acutely-dissociated-rat-submandibular-cells
#7
Kunkun Xia, Zegang Ma, Jianxin Shen, Menghan Li, Baoke Hou, Ming Gao, Shuijun Zhang, Jie Wu
Cellular Ca2+ signals play a critical role in cell physiology and pathology. In most non-excitable cells, store-operated Ca2+ entry (SOCE) is an important mechanism by which intracellular Ca2+ signaling is regulated. However, few drugs can selectively modulate SOCE. 2-Aminoethoxydiphenyl borate (2APB) and its analogs (DPB162 and DPB163) have been reported to inhibit SOCE. Here, we examined the effects of another 2-APB analog, DPB161 on SOCE in acutely-isolated rat submandibular cells. Both patch-clamp recordings and Ca2+ imaging showed that upon removal of extracellular Ca2+ ([Ca2+]o=0), rat submandibular cells were unable to maintain ACh-induced Ca2+ oscillations, but restoration of [Ca2+]o to refill Ca2+ stores enable recovery of these Ca2+ oscillations...
June 27, 2017: Oncotarget
https://www.readbyqxmd.com/read/28711494/development-of-membrane-ion-channels-during-neural-differentiation-from-human-embryonic-stem-cells
#8
Sara Mirsadeghi, Ebrahim Shahbazi, Katayoun Hemmesi, Shiva Nemati, Hossein Baharvand, Javad Mirnajafi-Zadeh, Sahar Kiani
OBJECTIVE: For human embryonic stem cells (hESCs) to differentiate into neurons, enormous changes has to occur leading to trigger action potential and neurotransmitter release. We attempt to determine the changes in expression of voltage gated channels (VGCs) and their electrophysiological properties during neural differentiation. MATERIALS AND METHODS: The relative expressions of α-subunit of voltage gated potassium, sodium and calcium channels were characterized by qRT-PCR technique...
July 12, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28711067/pa-6-inhibits-inward-rectifier-currents-carried-by-v93i-and-d172n-gain-of-function-kir2-1-channels-but-increases-channel-protein-expression
#9
Yuan Ji, Marlieke G Veldhuis, Jantien Zandvoort, Fee L Romunde, Marien J C Houtman, Karen Duran, Gijs van Haaften, Eva-Maria Zangerl-Plessl, Hiroki Takanari, Anna Stary-Weinzinger, Marcel A G van der Heyden
BACKGROUND: The inward rectifier potassium current IK1 contributes to a stable resting membrane potential and phase 3 repolarization of the cardiac action potential. KCNJ2 gain-of-function mutations V93I and D172N associate with increased IK1, short QT syndrome type 3 and congenital atrial fibrillation. Pentamidine-Analogue 6 (PA-6) is an efficient (IC50 = 14 nM with inside-out patch clamp methodology) and specific IK1 inhibitor that interacts with the cytoplasmic pore region of the KIR2...
July 15, 2017: Journal of Biomedical Science
https://www.readbyqxmd.com/read/28710467/human-ipsc-derived-cardiomyocytes-cultured-in-3d-engineered-heart-tissue-show-physiological-upstroke-velocity-and-sodium-current-density
#10
Marc D Lemoine, Ingra Mannhardt, Kaja Breckwoldt, Maksymilian Prondzynski, Frederik Flenner, Bärbel Ulmer, Marc N Hirt, Christiane Neuber, András Horváth, Benjamin Kloth, Hermann Reichenspurner, Stephan Willems, Arne Hansen, Thomas Eschenhagen, Torsten Christ
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a promising tool for drug testing and modelling genetic disorders. Abnormally low upstroke velocity is a current limitation. Here we investigated the use of 3D engineered heart tissue (EHT) as a culture method with greater resemblance to human heart tissue in comparison to standard technique of 2D monolayer (ML) format. INa was measured in ML or EHT using the standard patch-clamp technique. INa density was ~1.8 fold larger in EHT (-18...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28706450/reactive-oxygen-species-increase-neuronal-excitability-via-activation-of-nonspecific-cation-channel-in-rat-medullary-dorsal-horn-neurons
#11
Hae In Lee, Byung Rim Park, Sang Woo Chun
The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion (O2(·-)), on membrane excitability in the rat MDH neurons...
July 2017: Korean Journal of Physiology & Pharmacology
https://www.readbyqxmd.com/read/28706218/patch-clamp-assisted-single-neuron-lipidomics
#12
Collin B Merrill, Abdul Basit, Andrea Armirotti, Yousheng Jia, Christine M Gall, Gary Lynch, Daniele Piomelli
Our understanding of the physiological and pathological functions of brain lipids is limited by the inability to analyze these molecules at cellular resolution. Here, we present a method that enables the detection of lipids in identified single neurons from live mammalian brains. Neuronal cell bodies are captured from perfused mouse brain slices by patch clamping, and lipids are analyzed using an optimized nanoflow liquid chromatography/mass spectrometry protocol. In a first application of the method, we identified more than 40 lipid species from dentate gyrus granule cells and CA1 pyramidal neurons of the hippocampus...
July 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28701925/postsynaptic-gaba-b-receptors-contribute-to-the-termination-of-giant-depolarizing-potentials-in-ca3-neonatal-rat-hippocampus
#13
Ilgam Khalilov, Marat Minlebaev, Marat Mukhtarov, Elvira Juzekaeva, Roustem Khazipov
During development, hippocampal CA3 network generates recurrent population bursts, so-called Giant Depolarizing Potentials (GDPs). GDPs are characterized by synchronous depolarization and firing of CA3 pyramidal cells followed by afterhyperpolarization (GDP-AHP). Here, we explored the properties of GDP-AHP in CA3 pyramidal cells using gramicidin perforated patch clamp recordings from neonatal rat hippocampal slices. We found that GDP-AHP occurs independently of whether CA3 pyramidal cells fire action potentials (APs) or remain silent during GDPs...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28701305/redox-and-activation-of-protein-kinase-a-dysregulates-calcium-homeostasis-in-pulmonary-vein-cardiomyocytes-of-chronic-kidney-disease
#14
Shih-Yu Huang, Yao-Chang Chen, Yu-Hsun Kao, Ming-Hsiung Hsieh, Yung-Kuo Lin, Shih-Ann Chen, Yi-Jen Chen
BACKGROUND: Chronic kidney disease (CKD) increases the occurrence of atrial fibrillation and pulmonary vein (PV) arrhythmogenesis. Calcium dysregulation and reactive oxygen species (ROS) enhance PV arrhythmogenic activity. The purposes of this study were to investigate whether CKD modulates PV electrical activity through dysregulation of calcium homeostasis and ROS. METHODS AND RESULTS: Biochemical and electrocardiographic studies were conducted in rabbits with and without CKD (induced by 150 mg/kg per day neomycin sulfate and 500 mg/kg per day cefazolin)...
July 12, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28700658/nanosecond-electric-pulses-differentially-affect-inward-and-outward-currents-in-patch-clamped-adrenal-chromaffin-cells
#15
Lisha Yang, Gale L Craviso, P Thomas Vernier, Indira Chatterjee, Normand Leblanc
This study examined the effect of 5 ns electric pulses on macroscopic ionic currents in whole-cell voltage-clamped adrenal chromaffin cells. Current-voltage (I-V) relationships first established that the early peak inward current was primarily composed of a fast voltage-dependent Na+ current (INa), whereas the late outward current was composed of at least three ionic currents: a voltage-gated Ca2+ current (ICa), a Ca2+-activated K+ current (IK(Ca)), and a sustained voltage-dependent delayed rectifier K+ current (IKV)...
2017: PloS One
https://www.readbyqxmd.com/read/28698388/delayed-cryptochrome-degradation-asymmetrically-alters-the-daily-rhythm-in-suprachiasmatic-clock-neuron-excitability
#16
Sven Wegner, Mino D C Belle, Alun T L Hughes, Casey O Diekman, Hugh D Piggins
Suprachiasmatic nuclei (SCN) neurons contain an intracellular molecular circadian clock and the Cryptochromes (CRY1/2), key transcriptional repressors of this molecular apparatus, are subject to post-translational modification through ubiquitination and targeting for proteosomal degradation by the ubiquitin E3 ligase complex. Loss-of-function point mutations in a component of this ligase complex, Fbxl3, delay CRY1/2 degradation, reduce circadian rhythm strength, and lengthen the circadian period by ∼2.5h...
July 11, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28697840/-effect-of-high-fat-diet-on-expression-of-transient-receptor-potential-vanilloid-1-in-respiratory-tract-and-dorsal-root-ganglion-of-mice
#17
Lian Zhu, Zhi-Liang Xu
OBJECTIVE: To investigate the effect of high-fat diet on the expression of transient receptor potential vanilloid 1 (TRPV1) in the respiratory system and the dorsal root ganglion (DRG) of mice, as well as its effect on the excitability of sensory neurons. METHODS: A total of 20 C57BL/6 mice were randomly divided into normal-diet (ND) group and high-fat diet (HFD) group, with 10 mice in each group. The mice were given corresponding diets and body weights were monitored...
July 2017: Zhongguo Dang Dai Er Ke za Zhi, Chinese Journal of Contemporary Pediatrics
https://www.readbyqxmd.com/read/28696213/ca-2-regulation-of-cav3-3-t-type-ca-2-channel-is-mediated-by-calmodulin
#18
Narae Lee, Sua Jeong, Kang-Chang Kim, Jin-Ah Kim, Jin-Yong Park, Ho-Won Kang, Edward Perez-Reyes, Jung-Ha Lee
Numerous investigations reported that increases of internal Ca(2+) (Ca(2+)i) pivotally regulate high voltage-activated (HVA) Ca(2+) channels via calmodulin (CaM). However, it is largely elusive that Ca(2+)i can regulate low voltage-activated T-type Ca(2+) channels. Using whole cell patch clamp, we compared the biophysical properties of Ca(2+) current through T-type Ca(2+) channel Cav3.1, Cav3.2, or Cav3.3 stably expressed in HEK293 cells between internal solutions containing 27 nM and l μM free Ca(2+) Both activation and inactivation kinetics of Cav3...
July 10, 2017: Molecular Pharmacology
https://www.readbyqxmd.com/read/28688582/net-k-secretion-in-the-thick-ascending-limb-of-mice-on-a-low-na-high-k-diet
#19
Bangchen Wang, Donghai Wen, Huaqing Li, Jun Wang-France, Steven C Sansom
Because of its cardio-protective effects, a low-Na, high-K diet (LNaHK) is often warranted in conjunction with diuretics to treat hypertensive patients. However, it is necessary to understand the renal handling of such diets in order to choose the best diuretic. Wild-type (WT) or Renal Outer Medullary K channel (ROMK) knockout mice (KO) were given a regular (CTRL), LNaHK, or high-K diet (HK) for 4-7 days. On LNaHK, mice treated with either IP furosemide for 12 hrs, or given furosemide in drinking water for 7 days, exhibited decreased K clearance...
July 6, 2017: Kidney International
https://www.readbyqxmd.com/read/28685234/prostanoid-ep3-receptor-agonist-sulprostone-enhances-pacemaker-activity-of-colonic-interstitial-cells-of-cajal
#20
Man Woo Kim, Han Yi Jiao, Seok Won Kim, Chan Guk Park, Mei Jin Wu, Chansik Hong, Seok Choi, Jae Yeoul Jun
EP receptor activation by PGE2 regulates gastrointestinal motility by modulating smooth muscle contractility. Interstitial cells of Cajal (ICCs) are pacemaker cells that regulate smooth muscle activity. We aimed to determine effects of the EP3 receptor agonist sulprostone on pacemaker potentials in colonic ICCs. We performed a whole cell patch clamp, RT-PCR, and Ca(2+) imaging in cultured ICCs from mouse colon. Sulprostone depolarized the membrane and increased pacemaker frequency. EP3 receptor antagonist blocked these sulprostone-induced effects...
July 6, 2017: Naunyn-Schmiedeberg's Archives of Pharmacology
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