Search results for "Myocardium"

Chronic heart damage following doxorubicin treatment is alleviated by lovastatin.

2014

The anticancer efficacy of anthracyclines is limited by cumulative dose-dependent early and delayed cardiotoxicity resulting in congestive heart failure. Mechanisms responsible for anthracycline-induced heart damage are controversially discussed and effective preventive measures are preferable. Here, we analyzed the influence of the lipid lowering drug lovastatin on anthracycline-induced late cardiotoxicity three month after treatment of C57BL/6 mice with five low doses of doxorubicin (5×3mg/kg BW; i.p.). Doxorubicin increased the cardiac mRNA levels of BNP, IL-6 and CTGF, while the expression of ANP remained unchanged. Lovastatin counteracted these persisting cardiac stress responses evoke…

Differential effects of hypothermia on neuronal efflux, release and uptake of noradrenaline

1972

Isolated rabbit hearts were perfused at 34° (control), 24° or 12°C. The neuronal efflux of noradrenaline after perfusion with the amine for 1 h was depressed at 24° C (Q 10 about 5) in the presence or absence of desipramine; at 12°C the efflux was below the limit of estimation. Moderate reduction of the temperature (24° C) decreased the removal of perfused noradrenaline to about 60% of the control value and caused a 1.7-fold increase of the output of noradrenaline evoked by sympathetic nerve stimulation. It is concluded that the extremely temperature-dependent efflux of noradrenaline across the axonal membrane is not part of the release of noradrenaline evoked by nerve stimulation.

The interferance of muscarinic receptors with the noradrenaline release from sympathetic nerve endings caused by nicotinic agents.

1968

Transplantation of Mesenchymal Stem Cells Exerts a Greater Long-Term Effect than Bone Marrow Mononuclear Cells in a Chronic Myocardial Infarction Mod…

2010

The aim of this study is to assess the long-term effect of mesenchymal stem cells (MSC) transplantation in a rat model of chronic myocardial infarction (MI) in comparison with the effect of bone marrow mononuclear cells (BM-MNC) transplant. Five weeks after induction of MI, rats were allocated to receive intramyocardial injection of 106 GFP-expressing cells (BM-MNC or MSC) or medium as control. Heart function (echocardiography and 18F-FDG-microPET) and histological studies were performed 3 months after transplantation and cell fate was analyzed along the experiment (1 and 2 weeks and 1 and 3 months). The main findings of this study were that both BM-derived populations, BM-MNC and MSC, ind…

Interstitial washout and hydrolysis of acetylcholine in the perfused heart

1982

The efflux of acetylcholine, of radioactively labelled acetylcholine and choline, into the venous effluent of the perfused chicken heart was studied to determine the kinetics of both interstitial washout and hydrolysis of acetylcholine. Stimulation of both cervical vagus nerves (e.g., for 5 s at 40 Hz) caused a release of acetylcholine, which appeared partially unhydrolyzed in the venous effluent, and reduced force of contraction and heart rate. For comparison, labelled acetylcholine or choline was infused for 5 s into the heart and again the venous efflux of either substance was determined. It was found that the kinetics of efflux of acetylcholine or choline from the interstitial space wer…

Characterization of choline efflux from the perfused heart at rest and after muscarine receptor activation.

1986

The resting efflux of choline from perfused chicken hearts varied from 0.4 to 2.6 nmol/g min, but was constant for at least 80 min in the individual experiments. The rate of choline efflux was found to be equal to the rate of choline formation in the heart, which, from the following reasons, was essentially due to hydrolysis of choline phospholipids. Cardiac content of choline phospholipids (7,200 nmol/g) was much higher than that of acetylcholine (5.5 nmol/g). Resting release of acetylcholine was 0.016 nmol/g min and, after inhibition of cholinesterase, only about 0.1 nmol/g min. Resting efflux of choline was reduced by mepacrine, a phospholipase A2 inhibitor, by perfusion with a Ca2+-free…

Oxygen and substrate deprivation on isolated rat cardiac myocytes : temporal relationship between electromechanical and biochemical consequences

1990

The effects of hypoxia and reoxygenation on action potentials (AP), contractions, and certain biochemical parameters were studied in isolated rat ventricular myocytes in monolayer culture in the presence and absence of glucose. Substrate deprivation alone had no influence on the basal properties. In the presence of glucose, a 4-h hypoxic treatment caused only a moderate decrease in AP amplitude and rate. In substrate-free conditions, hypoxia induced a gradual decline in plateau potential level and in AP duration and rate, followed by rhythm abnormalities and a failure of the electromechanical coupling. Spontaneous AP generation then ceased, and the resting potential decreased with increase…

Sudden cardiac death due to anomalous origin of the right coronary artery: A case report in a child

2006

Magnetic resonance in isolated noncompaction of the ventricular myocardium

2010

Abstract Non-compaction of the ventricular myocardium (LCVM) is a rare disorder of myocardial morphogenesis usually diagnosed in paediatric age. The diagnosis was echocardiographically made on the basis of a reported spongeous/compacted ratio >2 in one or more segments of the left ventricle during the diastolic period. We aimed to test the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging in distinguishing pathological left ventricular non-compaction. Methods We collected a consecutive series of 8 patients, 5 males and 3 females, with a mean age of 14.9 years with non-compaction of left ventricular myocardium. All patients were admitted in our divisions of cardiology. I…

Aerobic Exercise During Advance Stage of Uncontrolled Arterial Hypertension

2021

Made available in DSpace on 2022-04-29T08:45:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-03 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidade Estadual Paulista Aim: To evaluate the influence of physical training on myocardial function, oxidative stress, energy metabolism, and MAPKs and NF-κB signaling pathways in spontaneously hypertensive rats (SHR), at advanced stage of arterial hypertension, which precedes heart failure development. Methods: We studied four experimental groups: normotensive Wistar rats (W, n = 27), trained W (W-EX, n = 31), SHR (n = 27), and exercised SHR (SHR-E…