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Marzouk S A - - 1997
In this paper, fabrication, characterization, and physiological application of a miniaturized amperometric lactate biosensor are described. The sensor is based on cross-linked lactate oxidase and tetrathiafulvalene-tetracyano-quinodimethane (TTF-TCNQ) charge transfer complex. The sensor was developed for continuous quantitative measurement of the lactate accumulation in ischemic myocardium under severe depletion of oxygen. ...
Fahey J T - - 1997
We previously observed young lambs to be more tolerant of hypoxia; compared with older lambs, they accumulate lactate at a slower rate during comparable reduction in cardiac output, and have a greater percent decrease in cardiac output before onset of systemic lactate accumulation. To determine the mechanism of lactic acidosis ...
Hofmann P - - 1997
In 1992 Conconi et al. (20) presented an indirect and noninvasive method for the determination of anaerobic threshold (AnT) in an incremental field test for runners. This noninvasive method for the determination of anaerobic threshold is dependent on the occurrence of a deflection of the heart rate performance curve (HRPC). ...
Thomas A N - - 1997
OBJECTIVE: To compare acid-base balance, lactate concentration, and haemodynamic and O2 transport variables during haemofiltration with replacement fluid containing 44.5 mmol/l Na+ lactate or 40 mmol/l Na+ HCO3- and 3 mmol/l lactic acid. DESIGN: A prospective, randomized trial. SETTING: A multidisciplinary, adult intensive care unit in a university hospital. PATIENTS: ...
Mendiola P - - 1997
Fish react to handling and capture with a burst of exercise that affects them deeply. The present study examines the effect of such severe exercise and the time course of recovery on the hematology (including spleen response) and metabolism of a population of cultured rainbow trout. Exercise was induced by ...
Smith E W - - 1997
The purpose of this study was to examine the effect of increment durations of 1-min and 4-min during progressive incremental exercise tests on: 1) the distribution of lactate between plasma and red blood cells (RBCs), and 2) lactate threshold (LT) detection via three conventional methods using whole blood lactate concentration ...
Zhou S - - 1997
The purpose of this study was to examine the reliability of using a mathematical method, D-max, to define blood lactate kinetics in response to an incremental exercise test, and to compare the physiological responses corresponding to the workload at D-max with those at the traditional 4 mmol l-1 lactate threshold ...
McLoughlin P - - 1997
BACKGROUND: Maximal exercise testing is used in patients with cystic fibrosis to assess functional status and prognosis. The lactate threshold is an index of aerobic fitness with significant advantages over maximal exercise tests. This study was undertaken to determine if the lactate threshold might be identified, non-invasively, in adult patients ...
Ardévol A A Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, - - 1997
To determine the relationship between muscle-derived lactate at fatigue and earlier onset of fatigue in the obese rat subjected to intense exercise. Rats were subjected to a short, intense exercise protocol on a treadmill. Blood was drawn from hind leg vein and artery during exercise and up to 1 h ...
Tanaka H - - 1997
Catecholamine concentrations are known to increase sharply in the blood at work rates above the blood lactate threshold (LT); thus, we hypothesized that the double product (DP, heart rate-systolic blood pressure product) may also abruptly increase at work rates above the LT. Ninety healthy students performed a stepwise incremental test ...
Møller P D - - 1997
The in vitro transport of L-lactate across rumen epithelium was found to be a passive, mass-action regulated diffusion, and no saturable transport mechanisms were involved at concentrations from 2-20 mmol/L. During this increase in L-lactate concentrations the epithelial resistance and potential difference increased significantly, indicating an epithelial change towards a ...
Myers J - - 1997
A number of general observations can be made from these recent studies. Lactate is a ubiquitous substance that is produced and removed from the body at all times, even at rest, both with and without the availability of oxygen. It is now recognized that lactate accumulates in the blood for ...
Doyle M R - - 1997
The purpose of this study was to investigate the effect of oral allithiamine administration on isokinetic parameters of muscle performance and lactate accumulation prior to, during and in recovery from isokinetic exercise. A double-blind, counterbalanced, crossover experimental design utilizing a Biodex System 2 Isokinetic Dynamometer was used to test 15 ...
Messonnier L - - 1997
The relationships between individual performance and lactate exchange and removal abilities were studies in 12 male rowers all subjected to three measurements on a rowing ergometer. An incremental exercise carried out to determine the maximal oxygen uptake (VO2max) and the corresponding maximal aerobic power (Pamax), a 2500-m all-out test where ...
Gudat U - - 1997
Metformin administration has been associated with substantial rises in blood lactate concentrations in individual Type 2 diabetic patients. Exercise also leads to increases in blood lactate levels. The objective of this study was to determine whether metformin administration augments the rise in plasma lactate concentrations during intermittent exercise in healthy ...
Bhambhani Y - - 1997
This study examined the acute effects of 10-ppm hydrogen sulfide (H2S) inhalation, a concentration equal to its occupational exposure limit, on the cardiovascular, metabolic, and biochemical responses in healthy volunteers. Fifteen men and 13 women completed two 30-minute exercise sessions at 50% of their maximal oxygen uptake, during which they ...
Smith J A - - 1997
We investigated whether uptake of lactate anions by red blood cells (RBC) during maximal exercise altered certain cellular physical properties including volume, density and osmotic fragility. Irrespective of whether individuals undertook 1 min of exercise at maximal effort or a progressive exercise test to exhaustion, whole-blood lactate concentration increased about ...
Webster M J - - 1997
The purpose of this study was to investigate the effect of a thiamin derivative, thiamin tetrahydrofurfuryl disulfide (TTFD), on oxygen uptake (VO2), lactate accumulation and cycling performance during exercise to exhaustion. Using a randomized, double-blind, cross-over design with a 10-day washout between trials, 14 subjects ingested either 1 g.day-1 of ...
Jansen R - - 1997
The electromyogram (EMG) median power frequency of the vastus lateralis and flexor digitorum superficialis muscles was measured in 12 subjects during cycle ergometry with step-wise increasing exercise intensities up to 100% of VO2max. Blood lactate concentration was measured to investigate the relationship between changes in lactate concentration and shifts in ...
Boulay M R - - 1997
Ventilatory and lactate thresholds have been proposed as tools to establish the highest steady-state intensity sustainable during prolonged physical exercise. The purposes of this study were to clarify whether the intensity at the ventilatory threshold could be sustained during prolonged high-intensity exercise and if the corresponding work rate, pulmonary ventilation, ...
Ament W - - 1997
It is known that the concentrations of ammonia and lactate in blood increase during incremental exercise. Sweat also contains lactate and ammonia. The aim of the present study was to investigate the physiological response of lactate and ammonia in plasma and sweat during a stepwise incremental cycle ergometer exercise test ...
Stockhausen W - - 1997
Any variation of the test protocol for incremental testing (IT) in cycle ergometry may affect the accuracy of the determination of anaerobic threshold (AnT). For lactate threshold concepts, indicating the maximum lactate steady-state (max Lass), the formation of the quasi-steady-state (QSS=95% of steady-state level) is evident. Previous studies have not ...
Maehara K - - 1997
We used near-infrared spectroscopy (NIRS) to test the hypothesis that reducing oxygen availability during exercise would affect the rate of muscle oxyhemoglobin (O2Hb) desaturation when performing work above the lactic acidosis threshold (LAT), but not below it. Seven healthy men each performed two constant work intensities (60%LAT and the LAT ...
Holloway S A - - 1996
To investigate the effect of acute induced metabolic alkalosis on the haematological, biochemical and metabolic responses to sprint exercise, six greyhound dogs with previously placed carotid arterial catheters were raced four times over a distance of 400 metres. Each dog was raced twice after receiving oral sodium bicarbonate solution (NaHCO3) ...
Gulbin J P - - 1996
The physiological profiles and proficiency of 32 volunteer surf life savers (LS), 15 professional lifeguards (LG), and 8 elite surf ironmen (IM) aged from 18 to 44 were compared. Measurements included anthropometry, muscular power, muscular strength-endurance, flexibility, VO2max, maximum heart rate, peak blood lactate response and proficiency in 3 rescue ...
Billat L V - - 1996
Time over a distance, i.e. speed, is the reference for performance for all events whose rules are based on locomotion in different mechanical constraints. A certain power output has to be maintained during a distance or over time. The energy requirements and metabolic support for optimal performance are functions of ...
Maltz E - - 1996
The balance of water, Na+, K+, Cl-, and total solute in the kidney and the N balance of the whole body were measured for six high yielding cows at 2 wk prepartum (period 1) and at 2 wk (period 2) and 7 wk (period 3) postpartum during winter and autumn ...
Guhl A - - 1996
Eight thoroughbred horses, trained for racing competition, were subjected to a standardised incremental speed test to determine the relationship between their blood lactate concentrations and running speed. Between 14 days before and 14 days after completing the standardised exercise test, the horses were timed for runs of 2000 to 6000 ...
Jackson D C - - 1996
To determine the fate of lactate during and after prolonged anoxia, 14C-labeled lactate was injected into turtles after 2 h of a 6-h submergence at 20 degrees C. 14C activities of plasma and chamber water were tested at intervals during anoxia and also in expired air during 39 h of ...
Lampert E - - 1996
Eight male patients with heart transplants at least a year after the operation were submitted to a 6-wk endurance training program and explored for their blood lactate kinetics before and after exercise. The tests consisted of a bicycle exercise upgraded by 20 W every 2 min until volitional fatigue. Training ...
Tappy L - - 1996
Sodium lactate inhibits ventilation when infused in healthy human subjects. This effect has been attributed to lactate-induced metabolic alkalosis. In order to further delineate the mechanisms responsible for this depression of ventilation, healthy humans were infused with sodium lactate with or without acetazolamide. Sodium lactate increased blood pH from 7.37 ...
Foxdal P - - 1996
Differences in blood lactate concentrations obtained during step-wise incremental and constant running exercise at the same intensities were investigated. In addition, the effect of endurance running at a constant intensity obtained by three different incremental modes (OBLA-4, 6 or 8 min) on the blood lactate concentration were studied. Eight firemen ...
Knight D R - - 1996
The normal rate of blood lactate accumulation during exercise is increased by hypoxia and decreased by hyperoxia. It is not known whether these changes are primarily determined by the lactate release in locomotory muscles or other tissues. Eleven men performed cycle exercise at 20, 35, 50, 92, and 100% of ...
MacLean D A - - 1996
1. This study examined the effects of a large (308 mg kg-1) oral dose of branched-chain amino acids (BCAAs) on muscle amino acid and ammonia (NH3) metabolism during 90 min of dynamic knee extensor exercise (64 +/- 2% of maximum workload). 2. BCAA supplementation resulted in a 4-fold increase in ...
Gullstrand L - - 1996
Six highly trained male elite rowers performed five sets of intermittent exercise on a rowing ergometer at competition intensity. Each set consisted of eight cycles of 15 s work and 15 s rest (15/15). Each set was repeated at 30-s intervals. Oxygen uptake and heart rate were continuously measured during ...
Cowett R M - - 1996
Pregnancy is considered diabetogenic. Although exercise has been advocated to assist in metabolic control of the nonpregnant diabetic individual, there is a paucity of data about the metabolic effects of exercise during pregnancy. To examine whether moderate exertion may be beneficial in the maintenance of maternal carbohydrate homeostasis, glucose and ...
Langfort J - - 1996
The effect of prolonged elevation of blood adrenaline concentration (sustained up to 60 h) on exercise performance and lactate threshold (TLA) was investigated in 24 rats on the basis of a incremental, multistage treadmill exercise test, performed before and after subcutaneous implantation of retard adrenaline tablets (15 mg), which release ...
Bilé A - - 1996
Incremental exercise tests have shown no difference in exercise capacity (EC), maximal oxygen uptake (VO2max), and ventilatory threshold (VT) in subjects with sickle cell trait (SCT) when compared to controls with normal hemoglobin (Hb). Nevertheless, during long and strenuous exercise testing, subjects with SCT exhibit comparable EC but lower oxygen ...
Huie M J - - 1996
We examined the hypotheses that 1) smoking acutely before exercise (AS) results in a higher rate of lactate production during exercise compared with chronic smoking with preexercise abstinence (CS) and 2) smokers have a higher rate of lactate conversion to glucose during exercise compared with nonsmokers (NS). To test our ...
Röcker L - - 1996
The effects of moderate 30 min cycle ergometer exercise (aerobic metabolism; 0.85-3.71 mmol.1(-1) lactate) followed by short-term exercise at maximal capacity (anaerobic metabolism; 5.09 to 17.75 mmol.1(-1) lactate) on endothelin (ET) and hemostatic variables (tissue plasminogen activator [t-PA] antigen, prothrombin fragments [F1,2], thrombin-antithrombin III complex [TAT], prothrombin time and partial ...
Lockett C J - - 1996
Lactate-edited 1H NMR difference spectra have been acquired from intact rat liver tissue following flushing and preservation in ice. A peak, initially at 1.26 ppm, was seen to increase in the liver tissue with preservation time. This peak was assigned to lactate, despite the fact that its chemical shift was ...
Stratton M D - - 1996
In previous studies we found that luminal perfusion of the isolated left colon of the rabbit with the hapten, trinitrobenzene, resulted in the production of an acute inflammatory process associated with alterations in eicosanoid metabolism. As the colitis was attenuated by cyclooxygenase inhibitors it is possible that the inflammation was ...
Topley N - - 1996
The inclusion of bicarbonate in the formulation of peritoneal dialysis solutions may avoid the in vitro impairment of certain cell functions seen with acidic lactate-based fluids. The supranormal physiological levels of HCO3- and PCO2 inherent in such formulations may, however, not be biocompatible. This study compared the in vitro biocompatibility ...
van Doorn C A - - 1996
BACKGROUND: Damage in latissimus dorsi muscle flaps has been reported after clinical and experimental cardiomyoplasty, and an ischemic origin has been suggested. METHOD: In situ, preconditioned latissimus dorsi muscles in 5 sheep were stimulated in either 1:1 (muscle: heart) or 1:2 synchrony with the systolic phase of the cardiac cycle, ...
Meierhenrich R - - 1996
To investigate EPO-induced increase of hemoglobin on energy metabolism plasma concentrations of lactate (L), pyruvate (P) and excess lactate (XL) were determined in ten dialysis patients at rest, immediately after 6 minutes of ergometric exercise as well as after recovery for 15 and 30 min. The investigations were performed before ...
Pach J - - 1996
In the paper a thorough study of the influence of the methemoglobin levels and the occurrence of certain syndromes of clinical symptoms was made in the inhabitants living in the immediate vicinity of the large refuse dumps. During a 2.5-day clinical hospitalization the following examinations were done: general medical, specialistic ...
Kraemer R R - - 1996
It has been recently suggested that high and sustained lactate levels may elicit increases in peripheral B-EN concentrations (16). We have observed elevated and sustained lactate concentrations in response to a low-volume resistive exercise protocol (14) that were similar to those from other exercise protocols that produced elevated beta-endorphin (B-EN) ...
Kittleson M D - - 1996
Twelve normal dogs and 7 dogs with experimentally induced heart failure were chronically instrumented to measure hemodynamic variables and blood gas tensions at rest and during graded treadmill exercise. Three groups of 4 normal dogs each (group 1, 15 to 20 kg; group 2, 21 to 30 kg; group 3, ...
Taylor S - - 1996
Adult rainbow trout (mass 600-1500 g; length 40-44 cm) were held in the laboratory for up to 28 days at seasonally appropriate temperatures. The maximal sustainable aerobic exercise level (involving slow-twitch muscle activity alone) was determined by following muscle recruitment patterns using electromyography. The mean (&plusmn; s.e.m.) speeds recorded for ...
Gleeson T T - - 1996
Most vertebrates utilize supplemental lactate production to support the energetic demands of vigorous, brief exercise. Despite similar patterns of accumulation, there appears to be a trichotomy with regards to lactate processing post-exercise. Most fish retain most of their lactate intramuscularly, using it for in situ glycogen replenishment. Recent evaluation of ...
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