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Langendorff heart

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https://www.readbyqxmd.com/read/28214609/evaluation-of-vascular-tone-and-cardiac-contractility-in-response-to-silver-nanoparticles-using-langendorff-rat-heart-preparation
#1
Ramirez-Lee Manuel Alejandro, Martinez-Cuevas Pedro Pablo, Rosas-Hernandez Hector, Oros-Ovalle Cuauhtémoc, Bravo-Sanchez Mariela, Martinez-Castañon Gabriel Alejandro, Gonzalez Carmen
Silver nanoparticles (AgNPs) have been widely used because of their antimicrobial properties. However, several reports suggest that AgNPs exposure promote cardiac effects that involve nitric oxide (NO) and oxidative stress (OS). Nevertheless, there are no studies related to AgNPs-induced effects in cardiac physiology. The aim of this study was to evaluate the AgNPs direct actions on coronary vascular tone and cardiac contractility using Langendorff rat heart preparation. Low concentrations of AgNPs (0.1 and 1μg/mL) increased NO derived from inducible NO-synthase (iNOS), without modifying cardiac parameters...
February 15, 2017: Nanomedicine: Nanotechnology, Biology, and Medicine
https://www.readbyqxmd.com/read/28213770/myosin-heavy-chain-and-cardiac-troponin-t-damage-is-associated-with-impaired-myofibrillar-atpase-activity-contributing-to-sarcomeric-dysfunction-in-ca-2-paradox-rat-hearts
#2
Árpád Kovács, Judit Kalász, Enikő T Pásztor, Attila Tóth, Zoltán Papp, Naranjan S Dhalla, Judit Barta
This study aimed to explore the potential contribution of myofibrils to contractile dysfunction in Ca(2+)-paradox hearts. Isolated rat hearts were perfused with Krebs-Henseleit solution (Control), followed by Ca(2+)-depletion, and then Ca(2+)-repletion after Ca(2+)-depletion (Ca(2+)-paradox) by Langendorff method. During heart perfusion left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of pressure development (+ dP/dt), and pressure decay (-dP/dt) were registered. Control LVDP (127...
February 17, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28213506/role-of-apamin-sensitive-calcium-activated-small-conductance-potassium-currents-on-the-mechanisms-of-ventricular-fibrillation-in-pacing-induced-failing-rabbit-hearts
#3
Dechun Yin, Yu-Cheng Hsieh, Wei-Chung Tsai, Adonis Zhi-Yang Wu, Zhaolei Jiang, Yi-Hsin Chan, Dongzhu Xu, Na Yang, Changyu Shen, Zhenhui Chen, Shien-Fong Lin, Peng-Sheng Chen, Thomas H Everett
BACKGROUND: Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF. METHODS AND RESULTS: Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation...
February 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28202246/analysis-of-myocardial-perfusion-parameters-in-an-ex-vivo-porcine-heart-model-using-third-generation-dual-source-ct
#4
Gert Jan Pelgrim, Taylor M Duguay, J Marco A Stijnen, Akos Varga-Szemes, Sjoerd Van Tuijl, U Joseph Schoepf, Matthijs Oudkerk, Rozemarijn Vliegenthart
PURPOSE: To evaluate the relationship between fractional flow reserve (FFR)-determined coronary artery stenosis severity and myocardial perfusion parameters derived from dynamic myocardial CT perfusion imaging (CTP) in an ex-vivo porcine heart model. METHODS: Six porcine hearts were perfused according to Langendorff. Circulatory parameters such as arterial blood flow (ABF) (L/min), mean arterial pressure (MAP) (mmHg) and heart rate (bpm) were monitored. Using an inflatable cuff and monitored via a pressure wire, coronary artery stenoses of different FFR grades were created (no stenosis, FFR = 0...
February 3, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28202059/cardiosphere-derived-cells-do-not-improve-cardiac-function-in-rats-with-cardiac-failure
#5
Taís Hanae Kasai-Brunswick, Andréa Rodrigues da Costa, Raiana Andrade Quintanilha Barbosa, Bruna Farjun, Fernanda Cristina Paccola Mesquita, Danúbia Silva Dos Santos, Isalira Peroba Ramos, Grazielle Suhett, Guilherme Visconde Brasil, Sandro Torrentes da Cunha, José Oscar R Brito, Juliana do Amaral Passipieri, Adriana Bastos Carvalho, Antonio Carlos Campos de Carvalho
BACKGROUND: Heart failure represents an important public health issue due to its high costs and growing incidence worldwide. Evidence showing the regenerative potential of postmitotic heart tissue has suggested the existence of endogenous cardiac stem cells in adult hearts. Cardiosphere-derived cells (CDC) constitute a candidate pool of such cardiac stem cells. Previous studies using acute myocardial infarction (MI) models in rodents demonstrated an improvement in cardiac function after cell therapy with CDC...
February 15, 2017: Stem Cell Research & Therapy
https://www.readbyqxmd.com/read/28195947/alpha-msh-induces-vasodilatation-and-exerts-cardioprotection-via-the-heme-oxygenase-pathway-in-rat-hearts
#6
Miklos Vecsernyes, Miklos Szokol, Mariann Bombicz, Daniel Priksz, Rudolf Gesztelyi, Gabor Aron Fulop, Balazs Varga, Bela Juhasz, David Haines, Arpad Tosaki
Alpha-melanocyte-stimulating hormone (α-MSH) is a protein with known capacity for protection against cardiovascular ischemia-reperfusion (I/R) injury. The present investigation evaluates the capacity of α-MSH to mitigate I/R effects in an isolated working rat heart model and determine the dependency of these alterations on the activity of heme oxygenase-1 (HO-1, hsp-32), a heat shock protein that functions as a major antioxidant defense molecule. Healthy male Sprague-Dawley rats were used for all experiments...
February 13, 2017: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/28194639/ultrafine-particulate-matter-increases-cardiac-ischemia-reperfusion-injury-via-mitochondrial-permeability-transition-pore
#7
Nathan A Holland, Chad R Fraiser, Ruben C Sloan, Robert B Devlin, David A Brown, Christopher J Wingard
Ultrafine particulate matter (UFP) has been associated with increased cardiovascular morbidity and mortality. However, the mechanisms that drive PM-associated cardiovascular disease and dysfunction remain unclear. We examined the impact of oropharyngeal aspiration of 100 μg UFP from the Chapel Hill, NC, air shed in Sprague-Dawley rats on cardiac function, arrhythmogenesis, and cardiac ischemia/reperfusion (I/R) injury using a Langendorff working heart model. We found that exposure to UFP was capable of significantly exacerbating cardiac I/R injury without changing overall cardiac function or major changes in arrhythmogenesis...
February 13, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/28194544/exploring-the-role-of-trpv-and-cgrp-in-adenosine-preconditioning-and-remote-hind-limb-preconditioning-induced-cardioprotection-in-rats
#8
Amritpal Singh, Puneet Kaur Randhawa, Anjana Bali, Nirmal Singh, Amteshwar Singh Jaggi
The cardioprotective effects of remote hind limb preconditioning (RIPC) are well known, but mechanisms by which protection occurs still remain to be explored. Therefore, the present study was designed to investigate the role of TRPV and CGRP in adenosine and remote preconditioning-induced cardioprotection, using sumatriptan, a CGRP release inhibitor and ruthenium red, a TRPV inhibitor, in rats. For remote preconditioning, a pressure cuff was tied around the hind limb of the rat and was inflated with air up to 150 mmHg to produce ischemia in the hind limb and during reperfusion pressure was released...
February 14, 2017: Cardiovascular Drugs and Therapy
https://www.readbyqxmd.com/read/28193783/remote-ischemic-preconditioning-triggers-changes-in-autonomic-nervous-system-activity-implications-for-cardioprotection
#9
Safa Abdul-Ghani, Arnold N Fleishman, Igor Khaliulin, Marco Meloni, Gianni D Angelini, M-Saadeh Suleiman
Cardioprotective efficacy of remote ischemic preconditioning (RIPC) remains controversial. Experimental studies investigating RIPC have largely monitored cardiovascular changes during index ischemia and reperfusion with little work investigating changes during RIPC application. This work aims to identify cardiovascular changes associated with autonomic nervous system (ANS) activity during RIPC and prior to index ischemia. RIPC was induced in anesthetized male C57/Bl6 mice by four cycles of 5 min of hindlimb ischemia using inflated cuff (200 mmHg) followed by 5 min reperfusion...
February 2017: Physiological Reports
https://www.readbyqxmd.com/read/28187689/evaluation-of-antihypertensive-potential-of-ficus-carica-fruit
#10
Alamgeer, Shifa Iman, Hira Asif, Muhammad Saleem
CONTEXT: Ficus carica L. (Moraceae) fruit is said to possess cardiovascular activity and has been used empirically in traditional phytotherapies for the treatment of hypertension and various other cardiovascular diseases. OBJECTIVE: This study investigated the antihypertensive and cardioinhibitory activity of the aqueous-methanol extract of F. carica fruit in rats. MATERIALS AND METHODS: Extract in 250, 500 and 1000 mg/kg doses (p.o.) were administered to normotensive Sprague Dawley rats and blood pressure was measured using non-invasive technique...
December 2017: Pharmaceutical Biology
https://www.readbyqxmd.com/read/28186163/label-free-detection-of-myocardial-ischaemia-in-the-perfused-rat-heart-by-spontaneous-raman-spectroscopy
#11
Suguru Ohira, Hideo Tanaka, Yoshinori Harada, Takeo Minamikawa, Yasuaki Kumamoto, Satoaki Matoba, Hitoshi Yaku, Tetsuro Takamatsu
Raman spectroscopy, which identifies intrinsic molecular constituents, has a potential for determining myocardial viability under label-free conditions. However, its suitability for evaluating myocardial ischaemia is undetermined. Focusing on cytochromes, i.e., representative molecules reflecting mitochondrial activity, we tested whether Raman spectroscopy is applicable for evaluating myocardial ischaemia especially during early ischaemic phase. We obtained spontaneous Raman spectra of the subepicardial myocardium in the Langendorff-perfused rat heart upon 532-nm excitation before and during the "stopped-flow," global ischaemia...
February 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28181692/irisin-plays-a-pivotal-role-to-protect-the-heart-against-ischemia-and-reperfusion-injury
#12
Hao Wang, Yu Tina Zhao, Shouyan Zhang, Patrycja M Dubielecka, Jianfeng Du, Naohiro Yano, Y Eugene Chin, Shougang Zhuang, Gangjian Qin, Ting C Zhao
Irisin, a newly identified hormone, is critical to modulating body metabolism, thermogenesis and reducing oxidative stresses. However, whether irisin protects the heart against myocardial ischemia and reperfusion (I/R) injury remains unknown. In this study, we determine the effect of irisin on myocardial I/R injury in the Langendorff perfused heart and cultured myocytes. Adult C57/BL6 mice were treated with irisin (100mg/kg) or vehicle for 30 minutes to elicit preconditioning. The isolated hearts were subjected to 30 min ischemia followed by 30 min reperfusion...
February 9, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/28179209/administration-of-anabolic-steroid-during-adolescence-induces-long-term-cardiac-hypertrophy-and-increases-susceptibility-to-ischemia-reperfusion-injury-in-adult-wistar-rats
#13
Fernando de Azevedo Cruz Seara, Raiana Andrade Quintanilha Barbosa, Dahienne Ferreira de Oliveira, Diorney Luiz Souza Gran da Silva, Adriana Bastos Carvalho, Andrea Claudia Freitas Ferreira, José Hamilton Matheus Nascimento, Emerson Lopes Olivares
Chronic administration of anabolic androgenic steroids (AAS) in adult rats results in cardiac hypertrophy and increased susceptibility to myocardial ischemia/reperfusion (IR) injury. Molecular analyses demonstrated that hyperactivation of type 1 angiotensin II (AT1) receptor mediates cardiac hypertrophy induced by AAS and also induces down-regulation of myocardial ATP-sensitive potassium channel (KATP), resulting in loss of exercise-induced cardioprotection. Exposure to AAS during adolescence promoted long-term cardiovascular dysfunctions, such as dysautonomia...
February 5, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28177679/reduced-expression-of-hcn-channels-in-sinoatrial-node-of-streptozotocin-induced-diabetic-rats
#14
Xin Huang, Nier Zhong, Hong Zhang, Aiqun Ma, Zuyi Yuan, Ning Guo
Diabetes mellitus (DM) is associated with an electrical remodeling of the heart, increasing risk of arrhythmias. However, knowledge of electrical remodeling in sinoatrial node (SAN) by DM is limited. We investigated the expression of HCN channel isoforms, HCN1-HCN4, in SAN from streptozotocin (STZ)-induced diabetic rats and the age-matched controls. We found that the STZ-induced diabetic rats have a lower intrinsic heart rate, a lengthened sinoatrial conduction time and rate-corrected maximal sinoatrial node recovery time in vivo as well as a longer cycle length (CL) in vitro as compared with the control...
December 23, 2016: Canadian Journal of Physiology and Pharmacology
https://www.readbyqxmd.com/read/28177123/katp-channel-inhibition-blunts-electromechanical-decline-during-hypoxia-in-left-ventricular-working-rabbit-hearts
#15
Kara Garrott, Sarah Kuzmiak-Glancy, Anastasia Wengrowski, Hanyu Zhang, Jack Rogers, Matthew Kay
Sarcolemmal KATP channel activation in isolated cells is generally understood, yet the relationship between myocardial oxygenation and KATP activation in excised working rabbit hearts remains unknown. We optically mapped action potentials (APs) in excised rabbit hearts to test the hypothesis that hypoxic changes would be more severe in LV working hearts (LWHs) than Langendorff (LANG) perfused hearts. We further hypothesized that KATP inhibition would prevent those changes. Optical APs were mapped while measuring LV developed pressure (LVDP), coronary flow rate (CFR), and oxygen consumption (MVO2 ) in LANG and LWHs...
February 8, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28162790/myocardial-ischemia-reperfusion-upregulates-the-transcription-of-the-neuregulin1-receptor-erbb3-but-only-postconditioning-preserves-protein-translation-role-in-oxidative-stress
#16
Michela Morano, Carmelina Angotti, Francesca Tullio, Giovanna Gambarotta, Claudia Penna, Pasquale Pagliaro, Stefano Geuna
BACKGROUND: Neuregulin1 (Nrg1) and its receptors ErbB are crucial for heart development and for adult heart structural maintenance and function and Nrg1 has been proposed for heart failure treatment. Infarct size is the major determinant of heart failure and the mechanism of action and the role of each ErbB receptor remain obscure, especially in the post-ischemic myocardium. We hypothesized that Nrg1 and ErbB are affected at transcriptional level early after ischemia/reperfusion (I/R) injury, and that the protective postconditioning procedure (PostC, brief cycles of ischemia/reperfusion carried out after a sustained ischemia) can influence this pathway...
January 31, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28132779/acute-infusion-of-levosimendan-enhances-atrial-fibrillation-in-an-experimental-whole-heart-model
#17
Gerrit Frommeyer, Anja Kohnke, Christian Ellermann, Dirk G Dechering, Simon Kochhäuser, Florian Reinke, Michael Fehr, Lars Eckardt
BACKGROUND: The calcium sensitizer levosimendan is clinically employed in decompensated heart failure. The aim of the present study was to assess effects of levosimendan on atrial electrophysiology in an experimental whole-heart model. METHODS AND RESULTS: 13 rabbit hearts were isolated and Langendorff-perfused. Thereafter, hearts were paced at cycle lengths of 350ms, 250ms and 200ms in the atrium. A standardized protocol employing atrial burst pacing induced atrial fibrillation (AF) in 4 of 13 hearts under baseline conditions (mean: 3...
January 18, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28123046/pde5-inhibitor-tadalafil-and-hydroxychloroquine-co-treatment-provides-synergistic-protection-against-type-2-diabetes-and-myocardial-infarction-in-mice
#18
Rui Wang, Lei Xi, Rakesh C Kukreja
Diabetes is associated with high risk of ischemic heart disease. We previously showed that phosphodiesterase 5 inhibitor - tadalafil (TAD) induces cardioprotection against ischemia/ reperfusion (I/R) injury in diabetic mice. Hydroxychloroquine (HCQ) is a widely used antimalarial and anti-inflammatory drug, which was reported to reduce hyperglycemia in diabetic patients. Therefore we hypothesized that combination of TAD and HCQ may induce synergistic cardioprotection in diabetes. We also investigated the role of insulin-Akt-mTOR signaling, which regulates protein synthesis and cell survival...
January 25, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/28108548/the-effect-of-left-ventricular-pacing-on-transmural-activation-delay-in-myopathic-human-hearts
#19
Andreu Porta-Sánchez, Paul Angaran, Stéphane Massé, Krishnakumar Nair, Talha Farid, Karthikeyan Umapathy, John Asta, Sigfus Gizurarson, Kumaraswamy Nanthakumar
AIMS: Left ventricular (LV) epicardial pacing (LVEpiP) in human myopathic hearts does not decrease global epicardial activation delay compared with right ventricular (RV) endocardial pacing (RVEndoP); however, the effect on transmural activation delay has not been evaluated. To characterize the transmural electrical activation delay in human myopathic hearts during RVEndoP and LVEpiP compared with global epicardial activation delay. METHODS AND RESULTS: Explanted hearts from seven patients (5 male, 46 ± 10 years) undergoing cardiac transplantation were Langendorff-perfused and mapped using an epicardial sock electrode array (112 electrodes) and 25 transmural plunge needles (four electrodes, 2 mm spacing), for a total of 100 unipolar transmural electrodes...
January 20, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28104480/the-effect-of-spatial-resolution-and-filtering-on-mapping-cardiac-fibrillation
#20
Benjamin King, Andreu Porta-Sánchez, Stéphane Massé, Nima Zamiri, Krishanand Balasundaram, Marjan Kusha, Nicholas Jackson, Shouvik Haldar, Karthikeyan Umapathy, Kumaraswamy Nanthakumar
BACKGROUND: Endocardial mapping tools use variable inter-electrode resolution whilst body surface mapping tools use narrow band pass filtering (BPF) to map fibrillatory mechanisms established by high resolution optical imaging. OBJECTIVES: To study the effect of resolution and BPF on the underlying mechanism being mapped. METHODS: Hearts from 14 healthy New Zealand white rabbits were Langendorff perfused. We studied the effect of spatial resolution and BPF on the location and characterization of rotors, by comparing phase singularities (PS) detected by high resolution un-filtered optical maps (OM), of fibrillating myocardium with decimated and filtered maps with simulated electrode spacing of 2, 5 and 8mm...
January 16, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
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