Search results for "Lactate"

Effects of resistance training frequency on cardiorespiratory fitness in older men and women during intervention and follow-up.

2017

This study investigated the effects of resistance training (RT) performed with different frequencies, including a follow-up period, on cardiorespiratory fitness in healthy older individuals. Eighty-eight men and women (69 ± 3 years, 167 ± 9 cm and 78 ± 14 kg) were randomly placed into four groups: training one- (M1 = 11, W1 = 12), two- (M2 = 7, W2 = 14), or three- (M3 = 11, W3 = 13) times-per-week or a non-training control group (MCon = 11, WCon = 9). During months 1–3, all subjects trained two-times-per-week while during the subsequent 6 months, training frequency was set according to the group. Oxygen consumption (cycling economy: CE), gross efficiency (GE), blood lactate concentrations (…

Effect of Eight Weeks' Physical Training on Muscle and Connective Tissue of the M. Vastus Lateralis in 69-year-old Men and Women

1977

Five one-hour exercise periods a week for 8 weeks included walking-jogging, swimming, gymnastics and ballgames for 26 healthy male and female 69-year-old pensioners. The mean maximal oxygen uptake of the men increased from 28.9 ml-kg-1-min-1 before training to 32.0 ml-kg-1-min-1 after training and for the women from 27.9 to 31.3 ml-kg-1-min-1. Muscle malate dehydrogenase activity was increased while that for lactate dehydrogenase decreased or remained the same. The activity of these enzymes was higher in the male both before and after training when compared with the female. However, the percentage number of slow twitch muscle fibers was nearly the same in both groups. Prolyl hydroxylase act…

Carbon Monoxide Protects Against Ischemia-reperfusion Injury in Vitro via Antioxidant Properties

2012

Carbon monoxide (CO) is believed to mediate many of the cytoprotective effects attributed to the activation of heme oxygenase (HO-1), the enzyme responsible for CO production. Recently, the study of CO-releasing molecules (CO-RMs) has provided a new approach for the delivery of CO. In the present study, we examined whether the cardioprotective properties of CO-RM2 in isolated rat hearts subjected to an ischemia-reperfusion (I/R) sequence were associated with the presence of CO. In addition, the antioxidant properties of CO-RM2 were evaluated. In hearts pretreated with CO-RM2, the improvement in contractile function at the end of the reperfusion period after 20 min of global total ischemia w…

Xenobiotic metabolizing enzymes of rat liver nonparenchymal cells.

1986

Abstract The nonparenchymal cells (NPC) of the liver are primarily located along the sinusoids and therefore are the first cells to encounter blood-borne xenobiotics. To study the possible role of the NPC in the metabolism of xenobiotics, populations of NPC and parenchymal cells (PC) were prepared from rats and various xenobiotic metabolizing enzyme activities investigated. The specific activity of every enzyme studied (ethoxyresorufin deethylase, benzphetamine demethylase, glutathione transferase, UDP glucuronosyltransferase, and microsomal epoxide hydrolase) was 12 to 1000% higher in the PC than in the NPC populations and the patterns of activities between the two populations were remarka…

Acute Administration of Epirubicin Induces Myocardial Depression in Isolated Rat Heart and Production of Radical Species Evaluated by Electron Spin R…

2007

The aim of our study was to evaluate the acute effect of epirubicin (EPI), an anthracycline anticancer drug, on the evolution of cardiac functional parameters and production of reactive oxygen/nitrogen species (RONS). Isolated perfused rat hearts were subjected to 70 minutes of EPI (10.3 microM) infusion and to 5 minutes of isoproterenol (ISO, 0.1 microM) at the end of the protocol. Coronary flow (CF), left ventricular developed pressure (LVDP), and lactate dehydrogenase (LDH) release in the coronary effluents were evaluated throughout the protocol. RONS were detected in the coronary effluents by electron spin resonance spectroscopy with a spin probe, 1-hydroxy-3-carboxy-pyrrolidine (CP-H, …

Effect of metal ion catalyzed oxidation of rifamycin SV on cell viability and metabolic performance of isolated rat hepatocytes.

1991

The effect of rifamycin SV on metabolic performance and cell viability was studied using isolated hepatocytes from fed, starved and glutathione (GSH) depleted rats. The relationships between GSH depletion, nutritional status of the cells, glucose metabolism, lactate dehydrogenase (LDH) leakage and malondialdehyde (MDA) production in the presence of rifamycin SV and transition metal ions was investigated. Glucose metabolism was impaired in isolated hepatocytes from both fed and starved animals, the effect is dependent on the rifamycin SV concentration and is enhanced by copper (II). Oxygen consumption by isolated hepatocytes from starved rats was also increased by copper (II) and a partial i…

Isolation, biochemical characterization, long-term culture, and phenotype modulation of oval cells from carcinogen-fed rats.

1993

Oval cells are liver epithelial cells that proliferate during hepatocarcinogenesis and chemically induced severe liver injury. It has been suggested that these cells represent hepatic stem cells which might play an important role in the histogenesis of cholangiocellular as well as hepatocellular carcinomas. In order to test this hypothesis highly purified oval cell preparations and propagable oval cell lines are needed. In the present study the isolation, biochemical characterization, and long-term culture of oval cells from rats fed a choline-deficient/DL-ethionine-supplemented diet for 6, 14, or 22 weeks are described. The freshly isolated oval cells were gamma-glutamyltranspeptidase-posi…

Long survival time of an isolated perfused rat brain

1972

Fatigue in a simulated cross-country skiing sprint competition

2009

The aim of this study was to assess fatigue during a simulated cross-country skiing sprint competition based on skating technique. Sixteen male skiers performed a 30-m maximal skiing speed test and four 850-m heats with roller skies on a tartan track, separated by 20 min recovery between heats. Physiological variables (heart rate, blood lactate concentration, oxygen consumption), skiing velocity, and electromyography (EMG) were recorded at the beginning of the heats and at the end of each 200-m lap during the heats. Maximal skiing velocity and EMG were measured in the speed test before the simulation. No differences were observed in skiing velocity, EMG or metabolic variables between the he…

The psychophysiological influence of exertion and affect on sport-specific cognitive and physical performance

2022

Objectives: The purpose of the present study was to examine differences in cognitive and physical performance, affective states, perceived exertion, and physiological responses between trials with cognitive, physical, or combined cognitive and physical load. Design: Randomised cross-over trial. Methods: Highly trained competitive orienteers (n = 15 men; n = 10 women) completed three randomised trials comprised of: (1) sport-specific cognitive tests; (2) 35-minute cycling time trial; and (3) combined sport-specific cognitive tests and 35-minute cycling time trial. Measures taken during the trials recorded affective states, perceived exertion, heart rate, blood lactate, cycling watts, as well…