Search results for "Lactate"

Fructose 2,6-bisphosphate and glycolytic flux in skeletal muscle of swimming frog

1990

AbstractGlycolytic flux in skeletal muscle is controlled by 6-phosphofructokinase but how this is achieved is controversial. Brief exercise (swimming) in frogs caused a dramatic increase in the phosphofructokinase activator, fructose 2,6-bisphosphate, in working muscle. The kinetics of phosphofructokinase suggest that in resting muscle, the enzyme is inhibited by ATP plus citrate and that the increase in fructose 2,6-bisphosphate is part of the mechanism to activate phosphofructokinase when exercise begins. When exercise was sustained, fructose 2,6-bisphosphate in muscle was decreased as was the rate of lactate accumulation. Glycolytic flux and the content of fructose 2,6-bisphosphate appea…

2018

Objective: High-intensity interval training (HIIT) can be extremely demanding and can consequently produce high blood lactate levels. Previous studies have shown that lactate is a potent metabolic stimulus, which is important for adaptation. Active recovery (ACT) after intensive exercise, however, enhances blood lactate removal in comparison with passive recovery (PAS) and, consequently, may attenuate endurance performance improvements. Therefore, the aim of this study was to examine the influence of regular ACT on training adaptations during a HIIT mesocycle. Methods: Twenty-six well-trained male intermittent sport athletes (age: 23.5 ± 2.5 years; O2max: 55.36 ± 3.69 ml min kg-1) participa…

A systematic review of physical fitness, physiological demands and biomechanical performance in equestrian athletes

2012

This article presents a systematic review of the literature investigating physical fitness, physiological demands and biomechanical performance in equestrian athletes. Three databases (SportsDiscus, CAB abstracts and PubMed) were searched to identify the literature. The main search term of ‘horse-riding’ was combined with eleven specific keywords (‘fitness’, ‘physiology’, ‘biomechanics’, ‘equestrian’, ‘athlete’, ‘co-ordination’, ‘heart rate’, ‘oxygen consumption’ ‘kinematic’ ‘EMG’ and ‘skill’). Exclusion criteria were: conference proceedings, abstracts, theses, and non-peer reviewed articles. Subsequently, 15 peer-reviewed papers were identified and included within this review. The main re…

Serum markers for early detection of patients with mesenteric ischemia after cardiac surgery

2018

AbstractObjectiveMesenteric ischemia (MESI) is a rare but often fatal complication in patients after cardiac surgery. Non-specific clinical symptoms and lack of specific laboratory parameters complicate the diagnosis. We evaluated potential serum markers for MESI in cardiac surgery patients.MethodsBetween March and October 2012, serial serum samples of 567 elective cardiac surgery patients were collected 1, 24, and 48 h after the operation, and concentrations of potential markers for MESI [α-glutathione-S-transferase (αGST), intestinal fatty-acid-binding protein (iFABP), and D-lactate] were measured retrospectively. In patients requiring laparotomy, blood samples obtained 72, 48, 24, and 12…

Innovative barriers for peritoneal adhesion prevention: liquid or solid? A rat uterine horn model.

2005

Objective To compare the effects of solid barriers (PDLA membrane and foil, Interceed), innovative barrier solutions (Adept and Hyalobarrier Gel, phospholipid emulsion), and Ringer’s lactate solution in preventing postsurgical peritoneal adhesions in the rat. Design Prospective, randomized experimental study. Setting Rat model in an academic research environment. Animal(s) Female, nonpregnant Wistar rats. Intervention(s) Standardized surgical injuries were applied to the parietal and visceral peritoneum and the uterine horns. The barrier agents were applied and the wound was closed. A second-look laparoscopy was performed 31 days after surgery to assess adhesion formation. Main Outcome Meas…

Relationship between Skin Temperature Variation and Muscle Damage Markers after a Marathon Performed in a Hot Environmental Condition

2021

This study aimed to assess the effect of a marathon running at a hot environmental temperature on the baseline skin temperature (Tsk) of the posterior day and to analyze the relationship between Tsk response and muscle damage markers variation. The Tsk, creatine kinase, and lactate dehydrogenase of 16 marathon runners were assessed four times before (15 days and 45 min) and after (24 h and 6 days) a marathon in a hot environment (thermal stress index = 28.3 ± 3.3 °C and humidity ~81%). The Tsk of thirteen different body regions of both right and left lower limbs were analyzed. Higher values after the marathon were observed than 45 min before in creatine kinase (174.3 ± 136.4 UI/L &lt

Sodium-hydrogen exchange inhibition: novel strategy to prevent myocardial injury following ischemia and reperfusion.

1999

Activation of Na+/H+ exchange and subsequent calcium overload in cardiac myocytes appear to play an important role in myocardial tissue injury following ischemia and reperfusion. Results of several in vitro studies in isolated myocytes and heart preparations and in vivo studies in pigs and rats have suggested that inhibition of Na+/H+ exchange is an effective means to prevent lethal reperfusion injury, arrhythmia, and improve myocardial contractile dysfunction. In patients with acute myocardial infarction (MI), any preventive agent is administered immediately before or shortly after reperfusion, rather than before the occurrence of coronary occlusion. The direct interventional approach to t…

Effect of Chronic Exercise Training on Blood Lactate Metabolism Among Patients With Type 2 Diabetes Mellitus : A Systematic Review and Meta-Analysis

2021

Purpose: To assess the effect of chronic exercise training on blood lactate metabolism at rest (i.e., basal lactate concentrations) and during exercise (i.e., blood lactate concentration at a fixed load, load at a fixed blood lactate concentration, and load at the individual blood lactate threshold) among patients with type 2 diabetes mellitus (T2DM).Methods: PubMed (MedLine), Embase, Web of Science, and Scopus were searched. Randomized controlled trials, non-randomized controlled trials, and case-control studies using chronic exercise training (i.e., 4 weeks) and that assessed blood lactate concentrations at rest and during exercise in T2DM patients were included.Results: Thirteen studies …

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…

What is Best Practice for Training Intensity and Duration Distribution in Endurance Athletes?

2010

Successful endurance training involves the manipulation of training intensity, duration, and frequency, with the implicit goals of maximizing performance, minimizing risk of negative training outcomes, and timing peak fitness and performances to be achieved when they matter most. Numerous descriptive studies of the training characteristics of nationally or internationally competitive endurance athletes training 10 to 13 times per week seem to converge on a typical intensity distribution in which about 80% of training sessions are performed at low intensity (2 mM blood lactate), with about 20% dominated by periods of high-intensity work, such as interval training at approx. 90% VO2max. Endur…