Search results for "HEART"

Morphometry of myocardial apex in endurance-trained mice of different ages

1979

Mitochondrial volume density, surface density of the outer mitochondrial membrane, the mean number and size of mitochondria, and the mean surface density of crista membranes together with the volume densities of myofibrils and sarcoplasmic space were morpho-metrically analyzed in cardiac muscle of two groups of sedentary control mice aged 3 and 7 months, and in two groups of mice trained either 1 month rather intensely or 4 months moderately. Of the calculated mitochondrial variables only the surface density of the outer mitochondrial membrane differed between the older controls and the older trained animals, the density being slightly smaller in the trained group. The myofibrillar volume d…

Depression mediates physical activity readiness and physical activity in patients with heart failure.

2021

Aims Although physical activity (PA) and exercise are essential for patients with heart failure (HF), adherence to the recommended guidelines is low. Not much is known about the mediating effect of HF patients mental state with their readiness for PA and reported activity levels. The purpose of this study is to investigate the mediatory effect of depression on PA readiness (physical limitation and psychological readiness) and self-reported PA in patients with HF. Methods and results In this cross-sectional study, 163 New York Heart Association Class I and II HF patients, during their clinic visit, reported on their physical limitation (PAR-Q) and psychological readiness [self-efficacy (ESES…

Expression of R-3-hydroxybutyrate dehydrogenase, a ketone body converting enzyme in heart and liver mitochondria of ruminant and non-ruminant mammals

1992

1. The properties of rat liver and bovine heart R-3-hydroxybutyrate dehydrogenase (BDH) have been extensively studied in the past 20 years, but little is known concerning the biogenesis and the regulation of this dehydrogenase over different species. 2. In addition, controversial results were often reported concerning the activity, the level and the subcellular location of this enzyme in ruminants. 3. BDH activity found in liver and kidney mitochondria from ruminants (cow and sheep) is low, while it is much higher in rat. 4. However, the enzyme activity is detected in microsomes and in cytosol of liver and of kidney cells from ruminants. These activities are not correlated to ketonaemia lev…

The Role of Heart Rate on the Associations Between Body Composition and Heart Rate Variability in Children With Overweight/Obesity: The ActiveBrains …

2019

The authors would like to thank all the participants who volunteered for this investigation. This work is the part of a Ph.D. Thesis conducted in the Biomedicine Doctoral Studies of the University of Granada, Spain.

European Society of Hypertension Working Group on Obesity Obesity-induced hypertension and target organ damage: current knowledge and future directio…

2009

Heart Rate Is a Better Predictor of Cardiorespiratory Fitness Than Heart Rate Variability in Overweight/Obese Children: The ActiveBrains Project

2019

The authors would like to thank all the participants who volunteered for this investigation. This work is part of a Ph.D. thesis conducted in the Biomedicine Doctoral Studies of the University of Granada, Spain.

Causal linear parametric model for baroreflex gain assessment in patients with recent myocardial infarction

2001

Spectral and cross-spectral analysis of R-R interval and systolic arterial pressure (SAP) spontaneous fluctuations have been proposed for noninvasive evaluation of baroreflex sensitivity (BRS). However, results are not in good agreement with clinical measurements. In this study, a bivariate parametric autoregressive model with exogenous input (ARXAR model), able to divide the R-R variability into SAP-related and -unrelated parts, was used to quantify the gain (αARXAR) of the baroreflex regulatory mechanism. For performance assessing, two traditional noninvasive methods based on frequency domain analysis [spectral, baroreflex gain by autogressive model (αAR); cross-spectral, baroreflex gain…

Lipid peroxidation capacities in the myocardium of endurance-trained rats and mice in vitro.

1992

The endurance-training programme in Experiment 1 (Exp. 1) consisted of a total swimming time of 149–159 h per male Han Wistar rat and in Experiment 2 (Exp. 2) the male NMRI-mice run on a treadmill at a speed of 25 m min-1 1 h per day, 5 days a week for 3 weeks. One group of the rat hearts was perfused with 0.3 mm cumene hydroperoxide (CumOOH) while the others were fractioned (mitochondria, sarcolemma and sarcoplasmic reticulum) and these cell fractions and homogenates were used to determine the total concentration of peroxidative lipids and the susceptibility to lipid peroxidation. The perfusion with CumOOH caused the release of thiobarbituric acid reactive substances (TBARS) into the perfu…

P330Modifications of short-term heart rate varibility and intrinsic pacemaker variability in an experimental model of metabolic syndrome

2018

60-Hour Sleep Deprivation Affects Submaximal but Not Maximal Physical Performance

2018

The effect of 60-h sleep deprivation (SD) on physical performance and motor control was studied. Twenty cadets were measured for aerobic performance (VO2) before and immediately after the SD period. Maximal strength and EMG of the knee extensor muscles were measured before and after 60 h of SD. Balance, reaction times and motor control were assessed every evening and morning during the SD period. Main effects were observed for heart rate (p = 0.002, partial eta squared: 0.669), VO2 (p = 0.004, partial eta squared: 0.621), ventilation (p = 0.016, partial eta squared: 0.049), and lactate concentration (p = 0.022, partial eta squared: 0.501), whereas RER remained unaltered (p = 0.213, partial …