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Langendorff heart

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https://www.readbyqxmd.com/read/28437281/cardioprotection-by-low-dose-of-estrogen-and-testosterone-at-the-physiological-ratio-on-ovx-rats-during-ischemia-reperfusion-injury
#1
Lu Fu, Yuyu Liu, Jiaxing Wang, Yu Sun, Lei Zhang, Ting Wu, Yiqian Li, Bin Wang, Shuting Huang, Huimin Bu, Hong Sun
Although estrogen and testosterone deficiency have often been associated with the development of cardiac diseases in postmenopausal women, the benefits of estrogen or testosterone therapy are controversial. Supplementation high dose of estrogen or testosterone alone has been associated with many side-effects, especially estrogen. This study was aimed to investigate whether supplementation of testosterone in combination with low-dose estrogen conferred stronger cardioprotective effects on ovariectomized rats subjected to ischemia/reperfusion (I/R) injury...
April 18, 2017: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/28429509/co2-permeability-and-carbonic-anhydrase-activity-of-rat-cardiomyocytes
#2
Mariela Arias-Hidalgo, Samer Al-Samir, Natalie Weber, Cornelia Geers-Knörr, Gerolf Gros, Volker Endeward
AIM: We determine here the CO2 permeability (PCO2 ) of plasma membranes of cardiomyocytes. These cells were chosen because heart possesses the highest rate of O2 -consumption/CO2 -production in the body. METHODS: Cardiomyocytes were isolated from rat hearts using the Langendorff technique. Cardiomyocyte suspensions exhibited a vitality of 2-14% and were studied by the previously described mass spectrometric (18) O-exchange-technique deriving PCO2 . We show by mass spectrometry and by carbonic anhydrase (CA)-staining that non-vital cardiomyocytes are free of CA and thus do not contribute to the mass spectrometric signal, which is determined exclusively by the fully functional vital cardiomyocytes...
April 20, 2017: Acta Physiologica
https://www.readbyqxmd.com/read/28413502/remifentanil-functions-in-the-adaptive-protection-of-cardiac-function-following-ischemia
#3
Jie Hou, Huishan Wang, Xinmin Li, Yan Zhu
The present study aimed to investigate the effects of remifentanil during adaptation followinsg myocardial ischemia, and its possible clinical applications. Remifentanil was used during the simulation of adaptation following ischemia, which was performed using a Langendorff heart perfusion system. A total of 75 rats were divided into five groups, and the coronary flow, cardiac output and the cardiac enzyme content in coronary effluent prior to ischemia and post-reperfusion were recorded. Electron microscopy was used to observe myocardial ultrastructure, and the volume of aortic and coronary effluent was also measured...
April 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28411229/a-comprehensive-analysis-of-myocardial-substrate-preference-emphasizes-the-need-for-a-synchronized-fluxomic-metabolomic-research-design
#4
Mukundan Ragavan, Alexander Kirpich, Xiaorong Fu, Shawn C Burgess, Lauren M McIntyre, Matthew E Merritt
The heart oxidizes fatty acids, carbohydrates and ketone bodies inside the citric acid cycle (CAC) to generate the reducing equivalents needed for ATP production. Competition between these substrates makes it difficult to estimate the extent of pyruvate oxidation. Previously, hyperpolarized pyruvate detected propionate mediated activation of carbohydrate oxidation, even in the presence of acetate. In this report, the optimal concentration of propionate for activation of glucose oxidation is measured in mouse hearts perfused in Langendorff mode...
April 14, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28410843/left-ventricular-hypertrophy-does-not-prevent-heart-failure-in-experimental-hypertension
#5
H Hernán Gómez Llambí, G Cao, M Donato, D Suárez, G Ottaviano, A Müller, B Buchholz, R Gelpi, M Otero-Losada, J Milei
BACKGROUND: Left ventricular hypertrophy (LVH) secondary to hypertension has been accepted to prevent heart failure (HF) while paradoxically increasing cardiovascular morbi-mortality. OBJECTIVES: To evaluate whether antihypertensive treatment inhibits LVH, restores beta-adrenergic response and affects myocardial oxidative metabolism. METHODS: Ninety spontaneously hypertensive rats (SHR) were distributed into groups and treated (mg/kg, p.o...
March 27, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28408160/physical-training-promotes-similar-effects-to-the-blockade-of-angiotensin-converting-enzyme-on-the-cardiac-morphology-and-function-in-old-female-rats-subjected-to-premature-ovarian-failure
#6
Ana Carolina S Felix, Sabrina G V Dutra, Ada C Gastaldi, Pâmela C Bonfim, Suenimeire Vieira, Hugo Celso Dutra de Souza
We investigated the effects of angiotensin-converting enzyme (ACE) inhibition and aerobic physical training on the heart of old female rats (82-wk-old) submitted to premature ovarian failure (10-wk.-old). We used different approaches: morphology and function by echocardiography, reactivity of the coronary bed and left ventricular contractibility (Langendorff Technique). Female Wistar ovariectomized (OVX) rats (n=42) were assigned to one of four groups: OVX, vehicle treated only; OVX-EM, Enalapril Maleate only (EM, 10mg·kg(-1)·d(-1)); OVX-T, aerobic trained only; and OVX-EMT, treated with Enalapril Maleate and aerobic trained...
April 10, 2017: Experimental Gerontology
https://www.readbyqxmd.com/read/28405241/design-and-synthesis-of-a-new-steroid-macrocyclic-derivative-with-biological-activity
#7
Maria López-Ramos, Lauro Figueroa-Valverde, Socorro Herrera-Meza, Marcela Rosas-Nexticapa, Francisco Díaz-Cedillo, Elodia García-Cervera, Eduardo Pool-Gómez, Regina Cahuich-Carrillo
The aims of this study were to evaluate the positive inotropic effect of a new macrocyclic derivative (compound 11) and characterize the molecular mechanism involved in its biological activity. The first step was achieved by synthesis of a macrocyclic derivative involving a series of reactions for the preparation of several steroid derivatives such as (a) steroid-pyrimidinone (3 and 4), (b) steroid-amino (5), (c) steroid-imino (6), (d) ester-steroid (7 and 8), and (e) amido-steroid (9 and 10). Finally, 11 was prepared by removing the tert-butyldimethylsilane fragment of 10...
April 2017: Journal of Chemical Biology
https://www.readbyqxmd.com/read/28392989/sevoflurane-postconditioning-protects-the-myocardium-against-ischemia-reperfusion-injury-via-activation-of-the-jak2-stat3-pathway
#8
Jianjiang Wu, Jin Yu, Peng Xie, Yiliyaer Maimaitili, Jiang Wang, Long Yang, Haiping Ma, Xing Zhang, Yining Yang, Hong Zheng
BACKGROUND: Sevoflurane postconditioning (S-post) has similar cardioprotective effects as ischemic preconditioning. However, the underlying mechanism of S-post has not been fully elucidated. Janus kinase signaling transduction/transcription activator (JAK2-STAT3) plays an important role in cardioprotection. The purpose of this study was to determine whether the cardioprotective effects of S-post are associated with activation of the JAK2-STAT3 signal pathway. METHODS: An adult male Sprague-Dawley (SD) rat model of myocardial ischemia/reperfusion (I/R) injury was established using the Langendorff isolated heart perfusion apparatus...
2017: PeerJ
https://www.readbyqxmd.com/read/28382073/at1-receptor-modulator-attenuates-the-hypercholesterolemia-induced-impairment-of-the-myocardial-ischemic-post-conditioning-benefits
#9
Yun-Wei Li, Yan-Ming Li, Yan Hon, Qi-Lin Wan, Rui-Li He, Zhi-Zhong Wang, Cui-Hua Zhao
BACKGROUND AND OBJECTIVES: Ischemic post-conditioning (PostC) has been demonstrated as a novel strategy to harness nature's protection against myocardial ischemia-reperfusion (I/R). Hypercholesterolemia (HC) has been reported to block the effect of PostC on the heart. Angiotensin II type-1 (AT1) modulators have shown benefits in myocardial ischemia. The present study investigates the effect of a novel inhibitor of AT1, azilsartan in PostC of the heart of normocholesterolemic (NC) and HC rats...
March 2017: Korean Circulation Journal
https://www.readbyqxmd.com/read/28381328/long-term-effect-of-a-chronic-low-protein-multideficient-diet-on-the-heart-hypertension-and-heart-failure-in-chronically-malnourished-young-adult-rats
#10
Luiza V P Mendes, Sabrina R Gonsalez, Leonardo M Oliveira-Pinto, Amaury Pereira-Acácio, Christina M Takiya, José H M Nascimento, Marcelo Einicker-Lamas, Adalberto Vieyra, Valéria M N Cunha, Lucienne S Lara
BACKGROUND: We investigated whether a chronic low-protein multideficient diet (BRD) from weaning turns on cardiovascular adaptive responses that could culminate in hypertension and heart failure. METHODS AND RESULTS: Systolic pressure (SP) and heart rate (HR) were determined in CTRL (normal diet) and BRD rats. Plasma albumin, plasma urea and urinary urea excretion decreased in BRD rats. In this group, echocardiography and the Langendorff technique showed: (i) increased HR and hypertension; (ii) decreased LVDP, dP/dtmax, dP/dtmin, cardiac output, ejection fraction, stroke volume and left ventricular diameter...
March 27, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28377726/lysophosphatidic-acid-pretreatment-attenuates-myocardial-ischemia-reperfusion-injury-in-the-immature-hearts-of-rats
#11
Haibo Chen, Si Liu, Xuewen Liu, Jinjing Yang, Fang Wang, Xiangfeng Cong, Xi Chen
The cardioprotection of the immature heart during cardiac surgery remains controversial due to the differences between the adult heart and the newborn heart. Lysophosphatidic acid (LPA) is a small bioactive molecule with diverse functions including cell proliferation and survival via its receptor: LPA1-LPA6. We previously reported that the expressions of LPA1 and LPA3 in rat hearts were much higher in immature hearts and then declined rapidly with age. In this study, we aimed to investigate whether LPA signaling plays a potential protective role in immature hearts which had experienced ischemia/reperfusion (I/R) injury...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28376800/glycemia-and-the-cardioprotective-effects-of-insulin-pre-conditioning-in-the-isolated-rat-heart
#12
Yosuke Nakadate, Hiroaki Sato, Takeshi Oguchi, Tamaki Sato, Akiko Kawakami, Tadahiko Ishiyama, Takashi Matsukawa, Thomas Schricker
BACKGROUND: While acute hyperglycemia has been shown to mitigate the beneficial effects of ischemic preconditioning, its effect on insulin-induced preconditioning remains unclear. METHODS: The study was designed to test the hypothesis that acute hyperglycemia diminishes the cardioprotective effects following a 20-min pre-ischemic pre-conditioning with insulin in the isolated rat heart using the Langendorff system. Forty hearts were assigned to receive modified Krebs-Henseleit (KH) buffer containing 0...
April 4, 2017: Cardiovascular Diabetology
https://www.readbyqxmd.com/read/28375904/the-cardioprotective-effect-of-dexmedetomidine-in-rats-is-dose-dependent-and-mediated-by-bkca-channels
#13
Friederike Behmenburg, Eileen Pickert, Alexander Mathes, André Heinen, Markus W Hollmann, Ragnar Huhn, Marc M Berger
The alpha-2 receptor agonist Dexmedetomidine (Dex) protects the heart against ischemia-reperfusion injury. We investigated the signaling cascade underlying Dex-induced acute cardioprotection, with special emphasis on large-conductance Ca2+-sensitive potassium (BKCa) channels. Rats were anesthetized with pentobarbital. Hearts were isolated, mounted on a Langendorff system and perfused with Krebs-Henseleit buffer. Hearts underwent 33 minutes of ischemia followed by 60 minutes of reperfusion. Before the beginning of ischemia, Dex was administered at different doses (0...
April 2017: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/28364393/lipid-emulsion-enhances-cardiac-performance-after-ischemia-reperfusion-in-isolated-hearts-from-summer-active-arctic-ground-squirrels
#14
Michele M Salzman, Qunli Cheng, Richard J Deklotz, Gurpreet K Dulai, Hunter F Douglas, Anna E Dikalova, Dorothee Weihrauch, Brian M Barnes, Matthias L Riess
Hibernating mammals, like the arctic ground squirrel (AGS), exhibit robust resistance to myocardial ischemia/reperfusion (IR) injury. Regulated preference for lipid over glucose to fuel metabolism may play an important role. We tested whether providing lipid in an emulsion protects hearts from summer-active AGS better than hearts from Brown Norway (BN) rats against normothermic IR injury. Langendorff-prepared AGS and BN rat hearts were perfused with Krebs solution containing 7.5 mM glucose with or without 1% Intralipid™...
March 31, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28362405/local-field-fluorescence-microscopy-imaging-cellular-signals-in-intact-hearts
#15
Yuriana Aguilar-Sanchez, Diego Fainstein, Rafael Mejia-Alvarez, Ariel L Escobar
In the heart, molecular signaling studies are usually performed in isolated myocytes. However, many pathological situations such as ischemia and arrhythmias can only be fully understood at the whole organ level. Here, we present the spectroscopic technique of local field fluorescence microscopy (LFFM) that allows the measurement of cellular signals in the intact heart. The technique is based on a combination of a Langendorff perfused heart and optical fibers to record fluorescent signals. LFFM has various applications in the field of cardiovascular physiology to study the heart under normal and pathological conditions...
March 8, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28344215/ethyl-acetate-fraction-of-allium-hirtifolium-improves-functional-parameters-of-isolated-hearts-of-diabetic-rats
#16
Sara Khaleghi, Mahvash Hesari, Aliashraf Godini, Dareuosh Shackebaei, Ali Mostafaie
OBJECTIVE: Allium hirtifolium (Persian shallot) has a hypoglycemic effect on diabetic animals. The aim of this study was to assess the effect of the ethyl acetate fraction of Allium hirtifolium on the function of isolated hearts of diabetic rats. METHODS: The control and diabetic animals were randomly divided into four groups: saline- or extract-treated controls (n=10 and n=6, respectively) and saline- or extract-treated diabetic rats (n=8 and n=9, respectively), which received normal saline or extract for four weeks by daily gavage...
March 22, 2017: Anatolian Journal of Cardiology
https://www.readbyqxmd.com/read/28324970/development-of-data-acquisition-components-for-simultaneous-recording-of-3d-epicardial-and-surface-ecg-signals-in-the-langendorff-perfusion-apparatus
#17
Ryan Wade Selby, Anup Jonchhe, Chen Kaplan, Coeli M Lopes, Behnaz Ghoraani
Sudden Cardiac Death (SCD) claims 7 million lives per year. The importance of myocardial electrogram (EGM) repolarization alternans and surface electrocardiogram (ECG) T-wave alternans is gaining traction for understanding the underlying SCD mechanisms. However, the relationship between the 3D spatial distribution of myocardial EGMs and surface ECG with respect to SCD has yet to be investigated. To make this happen, a modified data acquisition system has been developed and fabricated in conjunction with the Langendorff perfusion system to enable simultaneous recording and analysis of the 3D spatial distribution of myocardial EGMs and the surface ECG...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28316073/arrhythmic-effects-of-epac-mediated-ryanodine-receptor-activation-in-langendorff-perfused-murine-hearts-are-associated-with-reduced-conduction-velocity
#18
Mengye Li, Sandeep Hothi, Samantha C Salvage, Kamalan Jeevaratnam, Andrew A Grace, Christopher L-H Huang
Recent papers have attributed arrhythmic substrate in murine RyR2-P2328S hearts to reduced action potential (AP) conduction velocities (CV), reflecting acute functional inhibition and/or reduced expression of sodium channels. We explored for acute effects of direct Epac (exchange protein directly activated by cAMP)-mediated ryanodine receptor-2 (RyR2) activation on arrhythmic substrate and CV. Monophasic action potential recordings demonstrated that initial steady (8-Hz) extrinsic pacing elicited ventricular tachycardia (VT) in 0 of 18 Langendorff-perfused wild-type mouse ventricles before pharmacological intervention...
March 18, 2017: Clinical and Experimental Pharmacology & Physiology
https://www.readbyqxmd.com/read/28314848/effects-of-late-sodium-current-blockade-on-ventricular-refibrillation-in-a-rabbit-model
#19
Mohammed Ali Azam, Nima Zamiri, Stéphane Massé, Marjan Kusha, Patrick F H Lai, Govind K Nair, Nigel S Tan, Christopher Labos, Kumaraswamy Nanthakumar
BACKGROUND: After defibrillation of initial ventricular fibrillation (VF), it is crucial to prevent refibrillation to ensure successful resuscitation outcomes. Inability of the late Na(+) current to inactivate leads to intracellular Ca(2+) dysregulation and arrhythmias. Our aim was to determine the effects of ranolazine and GS-967, inhibitors of the late Na(+) current, on ventricular refibrillation. METHODS AND RESULTS: Long-duration VF was induced electrically in Langendorff-perfused rabbit hearts (n=22) and terminated with a defibrillator after 6 minutes...
March 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28299825/fingolimod-gilenya-%C3%A2-in-multiple-sclerosis-bradycardia-atrioventricular-blocks-and-mild-effect-on-the-qtc-interval-something-to-do-with-the-l-type-calcium-channel
#20
Sylvie Pilote, Chantale Simard, Benoit Drolet
Cardiac arrhythmias and ECG abnormalities including bradycardia, prolongation of the QT interval, and atrioventricular (AV) conduction blocks have been extensively observed with fingolimod, the first marketed oral drug for treating the relapsing-remitting form of multiple sclerosis. This study was aiming to further elucidate the effects of fingolimod on cardiac electrophysiology at three different levels: (i) in vitro, (ii) ex vivo, and (iii) in vivo. (i) Patch-clamp experiments in whole cell configuration were performed on Cav 1...
March 16, 2017: Fundamental & Clinical Pharmacology
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