Smooth Muscle video: Smooth muscle excitation contraction coupling
Human Physiology" is a free online course on Janux that is open to anyone. Learn more at http://janux.ou.edu. Created by the University of Oklahoma, Janux is an interactive learning community ...http://smooth-muscle.purzuit.com/video/PfxCZXOh-bY.html
Abstract 793: Identification and Characterization of a Novel Mutation in JPH2-Encoded Junctophilin-2 in an Italian Hypertrophic...
Background Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden death in young athletes. While genes encoding 8 key myofilament proteins represent the most common genetic subtype of HCM known as sarcomeric HCM, we established mutations in JPH2-encoded junctophilin-2 as a novel pathogenic mechanism for HCM based on its role in stabilizing the cardiac dyad for efficient calcium-induced calcium-release (CICR). Here, we sought to validate JPH2 as a novel HCM-susceptibility gene by analyzing an independent cohort of patients with HCM.. Methods Utilizing polymerase chain reaction, denaturing high performance liquid chromatography, and DNA sequencing, comprehensive open reading frame/splice site mutation analysis of JPH2 was performed on 203 unrelated Italian patients with HCM (73 female, 43±18 years at diagnosis, maximal left ventricular wall thickness 23±6 mm) enrolled consecutively in Florence, Italy since 2002. To assess the implications of mutations on intracellular calcium, ...http://circ.ahajournals.org/content/116/Suppl_16/II_153.1
Kursus: 2016-2017 Cardiovascular Physiology - Efter- og videreuddannelse, Københavns Universitet
This course is theoretical and covers the integrated physiology of the cardiovascular system. Subjects include: EC coupling and cardiac output, pacemaking, ECG and arrhythmia, blood flow, blood pressure and vascular resistance, the endothelial cell, solute exchange, vascular smooth muscle, control of blood vessels and blood pressure regulation, circulation, cardiovascular receptors and responses, and pathological situations.. Learning Outcome. Knowledge:. - Electrical impulses in the heart. - Ion current and ECG. - Excitation contraction coupling. - Pumping of the heart. - Regulation of the heart beat. - Malfunction of the heart. - Cardiac output and peripheral pulse. - Flow, pressure and resistance. - Endothelial cells. - Microcirculation and solute exchange. - Vascular smooth muscle cells. - Control of blood vessels. - Cardiovascular receptors. - Co-ordinated cardiovascular responses. Skills:. - ...http://efteruddannelse.kurser.ku.dk/course/2016-2017/SMOK14001U
A specific cyclic ADP-ribose antagonist inhibits cardiac excitation-contraction coupling. - Department of Pharmacology
BACKGROUND: Cyclic ADP-ribose (cADPR) has been shown to act as a potent cytosolic mediator in a variety of tissues, regulating the release of Ca2+ from intracellular stores by a mechanism that involves ryanodine receptors. There is controversy over the effects of cADPR in cardiac muscle, although one possibility is that endogenous cADPR increases the Ca2+ sensitivity of Ca2+-induced Ca2+ release (CICR) from the sarcoplasmic reticulum. We investigated this possibility using 8-amino-cADPR, which has been found to antagonize the Ca2+-releasing effects of cADPR on sea urchin egg microsomes and in mammalian cells (Purkinje neurons, Jurkat T cells, smooth muscle and PC12 cells). RESULTS: In intact cardiac myocytes isolated from guinea-pig ventricle, cytosolic injection of 8-amino-cADPR substantially reduced contractions and Ca2+ transients accompanying action potentials (stimulated at 1Hertz). These reductions were not seen with injection of HEPES buffer, with ...https://pharm.ox.ac.uk/publications/677868
Spark-Induced Sparks As a Mechanism of Intracellular Calcium Alternans in Cardiac Myocytes | Circulation Research
Intracellular calcium (Ca) cycling plays a central role in cardiac excitation-contraction coupling.1,2 Ca alternans, a beat-to-beat alternation in intracellular Ca transient amplitude, is an important factor promoting T-wave alternans and pulsus alternans, markers conferring an increased risk of sudden cardiac death.3 Although Ca alternans has been widely studied in cardiac myocytes,4-13 the underlying mechanism remains controversial. Eisner et al4 were the first to propose that Ca alternans could be explained by a steep nonlinear dependence of sarcoplasmic reticulum (SR) Ca release on the diastolic SR Ca load immediately preceding the release (a steep fractional release-load relationship). This mechanism requires that diastolic SR Ca load alternate concomitantly with SR Ca release. Subsequent experimental6,7,9 and theoretical9,14,15 studies have provided evidence supporting this mechanism. However, later ...http://circres.ahajournals.org/content/106/10/1582
J11 Investigating phenocopies in a cohort of south african patients with a huntington's disease-like phenotype | Journal of...
Background Huntington's disease (HD) is caused by an unstable expanded trinucleotide (CAG) repeat in the huntingtin (HTT) gene. Presentation involves a clinical triad of symptoms: behavioural problems, movement disorder and cognitive decline. Elsewhere, between 1 and 7% of individuals diagnosed do not carry the mutation and are said to have an HD phenocopy; a term used to describe any syndrome that manifests HD-like symptoms in the absence of an HTT expansion. In South Africa, direct mutation testing is performed in the public sector by the National Health Laboratory Service. Approximately 30% of patients referred for confirmation of an HD diagnosis do not carry an HTT expansion. Huntington's disease-like 2 (HDL2) has recently been incorporated into routine diagnostic testing for HD referrals as up to one third of patients negative for the HTT expansion were found to carry an expansion in the underlying junctophilin-3 (JPH3) gene. ...http://jnnp.bmj.com/content/87/Suppl_1/A79.1
Anti-Junctophilin-2 antibody (ab79071) | Abcam
Rabbit polyclonal Junctophilin-2 antibody validated for WB, ELISA and tested in Human, Mouse and Rat. Referenced in 1 publication and 1 independent review…http://www.abcam.com/junctophilin-2-antibody-ab79071.html
Mechanisms of Altered Excitation-Contraction Coupling in Canine Tachycardia-Induced Heart Failure, I | Circulation Research
Mechanistic studies of human heart failure are complicated by the prolonged time course of development of the disease, the technical challenges of isolating cardiac tissue or cells from explanted hearts, the inability to investigate the early time course of cellular alterations, and the lack of control over experimental conditions. Thus, it is fortunate that the canine tachycardia-induced heart failure model so closely reproduces the known hemodynamic and ionic changes that have been identified in human hearts. The present findings indicate that, in addition to the electrophysiological changes noted in earlier studies, significant alterations in Ca2+ handling occur in isolated myocytes from failing hearts, following the general pattern of human studies. Through biochemical and functional measurements in the same hearts, we have found strong evidence in support of the hypothesis that the induction of heart failure triggers a shift in the balance of cytosolic Ca2+ extrusion mechanisms from SR ...http://circres.ahajournals.org/content/84/5/562
ß-Adrenergic Stimulation Synchronizes Intracellular Ca2+ Release During Excitation-Contraction Coupling in Cardiac Myocytes |...
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KAKEN - Research Projects | Effect of adrenomedullin on excitation-contraction coupling and abnormal automaticity in excised...
Principal Investigator：IMANISHI Sunao, Project Period (FY)：1997 - 1998, Research Category：Grant-in-Aid for Scientific Research (C), Section：一般, Research Field：Circulatory organs internal medicinehttps://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670767/
Recent studies have shown that beta 2-adrenergic receptor (beta 2-AR)-stimulated increases in the intracellular Ca2+ (Cai) transient and contraction in cardiac myocytes are dissociated from the increase in adenosine 3',5'-cyclic monophosphate (cAMP) level and are not accompanied by an increase in phospholamban phosphorylation, an acceleration in relaxation, or a reduction in myofilament Ca2+ response. Thus we hypothesized that the beta 2-AR modulation of cardiac excitation-contraction (EC) coupling may be mediated by either a cAMP-independent mechanism or a compartmentalized cAMP pathway. To directly distinguish between these two possibilities, the responses of the L-type Ca2+ current (ICa), Cai transient, and contraction to beta 2-AR as well as to beta 1-AR stimulation were examined in rat ventricular myocytes in the presence or absence of specific inhibitory cAMP analogs, Rp diastereomers ...http://ajpheart.physiology.org/content/273/3/H1611
Our study demonstrates that drugs that stimulate the AC/PKA pathway can increase cardiac contractions initiated by CICR and/or the VSRM. Forskolin or IBMX caused a nonselective increase in contractions and inward currents. In contrast, amrinone, which selectively inhibits PDE III, increased the amplitude of VSRM contractions with virtually no effect on CICR or ICa-L. All three agents increased the fraction of SR Ca2+ stores released by depolarizations typically used to activate the VSRM. However, none of these drugs increased the fraction of Ca2+released from the SR by CICR. These observations demonstrate that drugs that stimulate the AC/PKA pathway can modulate the VSRM, and that the VSRM can be modulated independently of effects on CICR and ICa-L.. The AC/PKA pathway phosphorylates several protein targets important in excitation-contraction coupling. These targets include L-type Ca2+ ...http://jpet.aspetjournals.org/content/298/3/954
Reinhold Penner, MD, PhD
The laboratory studies the mechanisms of inter- and intracellular signal transduction and its main goal is to elucidate the functional properties of molecular components involved in the complex regulation of secretion, excitation-contraction coupling, cell proliferation, and apoptosis. All research projects are guided by our desire to understand the relevant clinical context in which the molecular mechanisms operate, whether human disease states are causally linked or impacted, and ultimately how these mechanisms can be modified pharmacologically or genetically to treat patients. Our research primarily concentrates on four clinical areas: immune disorders (autoimmune diseases, allergy, inflammation), metabolic disorders (diabetes), anoxic disorders (stroke), and oncologic disorders (various cancers). The approach to study signaling events is mainly at the single-cell level and employs a variety of biophysical techniques (e.g., electrophysiology and digital ...http://uhcancercenter.org/index.php/about-us/directory/faculty-staff/88
T-tubule structural abnormalities in myotubularin morph | Open-i
T-tubule structural abnormalities in myotubularin morphant muscle.T-tubule (vertical arrows) and sarcoplasmic reticulum (angled arrows) abnormalities as demonsthttps://openi.nlm.nih.gov/detailedresult.php?img=PMC2631153_pgen.1000372.g009&req=4
The power of light-matter coupling
Strasbourg, France (SPX) Feb 12, 2015 - Light and matter can be so strongly linked that their characteristics become indistinguishable. These light-matter couplings are referred to as polaritons. Their energy oscillates continuously betwehttp://www.spacedaily.com/reports/The_power_of_light_matter_coupling_999.html
Stem Cell Blog - Analysis of published results of clinical trials in regenerative medicine | Cell Trials
About two years ago I attempted to analyze published results of regenerative medicine clinical studies. It was very hard and time consuming thing to do, so I've ditched my efforts. Recently, I was very happy to find a study byhttp://celltrials.info/2017/05/06/analysis-publications-clinical-trial-results-regenerative-medicine/
CACHE . Differences in Skeletal Muscle Growth by Concentric, Eccentric, and Isometric Contractions . Kalamazoo College
How muscles grow and why they grow differently in people is a very common question within the field of exercise science. The general population and even specialized athletes try to get the most out of their training by maximizing muscle growth. In order to maximize muscle growth, a person must put a load on the muscles that is greater than the average load the body puts on the muscles in everyday life. This does three things to the muscles and the body. It creates muscle tension, muscle damage, and metabolic stress which are needed for the muscle to grow. The process by which this load is put on occurs in one or a combination of three different types of muscle activity. These muscle activities are concentric muscle contraction, eccentric muscle contraction, and isometric muscle contraction. These contractions that put the loads on the muscles are dictated by which types of exercises the participant is doing. Concentric ...https://cache.kzoo.edu/handle/10920/30710
Biology-Online • View topic - Muscle Contraction: Strength
A muscle contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten or remain the same. Though the term 'contraction' implies a shortening or reduction, when used as a scientific term referring to the muscular system contraction refers to the generation of tension by muscle fibers with the help of motor neurons. Locomotion in most higher animals is possible only through the repeated contraction of many muscles at the correct times. Contraction is controlled by the central nervous system (CNS), which comprises the brain and spinal cord. Voluntary muscle contractions are initiated in the brain, while the spinal cord initiates involuntary reflexes ...http://www.biology-online.org/biology-forum/about13979.html?p=101767&hilit=Cord+factor
Postural muscle contraction legal definition of postural muscle contraction
Definition of postural muscle contraction in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is postural muscle contraction? Meaning of postural muscle contraction as a legal term. What does postural muscle contraction mean in law?http://legal-dictionary.thefreedictionary.com/postural+muscle+contraction
AID 59407 - Tested for in vivo smooth muscle contractile activity, expressed as MI100 (dose to give 100 of motor index after ig...
BioAssay record AID 59407 submitted by ChEMBL: Tested for in vivo smooth muscle contractile activity, expressed as MI100 (dose to give 100 of motor index after ig administration)..https://pubchem.ncbi.nlm.nih.gov/bioassay/59407
Superoxide Modulates Myogenic Contractions of Mouse Afferent Arterioles | Hypertension
The main new findings from this study of afferent arterioles from normal C57BL/6 mice were that increasing the PP from 40 to 80 mm Hg caused a myogenic contraction accompanied by an increase in ROS signal whether detected by dihydroethidium or tempo-9AC. The fluorescent ROS signal was predominately O2 · −, because it was reduced by incubation with PEG-SOD or Tempol but not with PEG-CAT and was upstream from Ca2+ because it persisted in Ca2+-free medium. Incubation of vessels with Tempol, PEG-SOD, apocynin, or DPI reduced basal and myogenic tone, whereas PEG-CAT was not effective, indicating that the responses were enhanced by O2 · − generated from NADPH oxidase. The moderation of myogenic contractions by Tempol was prevented by preincubation with PEG-SOD but was preserved by preincubation with PEG-CAT. H2O2 caused contractions at concentrations ,50 μmol/L but inhibited myogenic responses at 25 μmol/L. l- NAME increased basal tone but did not affect ...http://hyper.ahajournals.org/content/58/4/650
Isotonic Muscle Contraction | Article about Isotonic Muscle Contraction by The Free Dictionary
Looking for Isotonic Muscle Contraction? Find out information about Isotonic Muscle Contraction. contraction of a muscle at unchanging tension, expressed in a decrease in its length and an increase in its transverse section. Purely isotonic muscle... Explanation of Isotonic Muscle Contractionhttps://encyclopedia2.thefreedictionary.com/isotonic+muscle+contraction
Contraction of muscle - definition of contraction of muscle by The Free Dictionary
Define contraction of muscle. contraction of muscle synonyms, contraction of muscle pronunciation, contraction of muscle translation, English dictionary definition of contraction of muscle. Noun 1. muscle contraction - a shortening or tensing of a part or organ contraction, muscular contraction shortening - act of decreasing in length; 'the...https://www.thefreedictionary.com/contraction+of+muscle
A New Paradigm of Muscle Contraction - The University of Auckland
Since the discovery of the sliding filament and cross-bridge theories of muscle contraction more than half a century ago, force production and contraction in skeletal muscles have been associated exclusively with the contractile filaments actin and myosin. Recently, the structural protein titin, has emerged as a third filament contributing to active force regulation and contraction. In the past decade, we have attempted to identify the role of titin in force regulation during eccentric contraction and found that titin can regulate its stiffness upon activation and active, actin-myosin based force production. Likely, titin's force regulatory role occurs in two ways: (i) by binding calcium upon activation and thus becoming stiffer, and (ii) by attaching its proximal segments to actin, thereby shortening its free spring length and thus become stiffer and stronger in active compared to passive eccentric contractions. Modeling ...http://www.abi.auckland.ac.nz/en/about/events/2016/a-new-paradigm-of-muscle-contraction.html
Self-Regulation of Motor Force Through Chemomechanical Coupling in Skeletal Muscle Contraction | Journal of Applied Mechanics |...
It is intriguing how the mechanics of molecular motors is regulated to perform the mechanical work in living systems. In sharp contrast to the conventional wisdom, recent experiments indicated that motor force maintains ∼6 pN upon a wide range of filament loads during skeletal muscle contraction at the steady state. Here we find that this rather precise regulation which takes place in an essentially chaotic system, can be due to that a "working" motor is arrested in a transitional state when the motor force is ∼6 pN. Our analysis suggests that the motor force can be self-regulated through chemomechanical coupling, and motor force homeostasis is a built-in feature at the level of a single motor, which provides insights to understanding the coordinated function of multiple molecular motors existing in various physiological processes. With a coupled stochastic-elastic numerical framework, the kinetic model for a Actin-myosin-ATP cycle constructed in this work might pave the way ...http://appliedmechanics.asmedigitalcollection.asme.org/article.aspx?articleid=1713520&resultClick=1