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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 ...
Galloway S D - - 1996
To examine the effects of alkalosis on the metabolic response to prolonged exercise, seven healthy males cycled for 1 h at approximately 70% of maximum oxygen uptake on two occasions, 1-week apart. Starting 3 h prior to exercise, subjects consumed either CaCO3 (placebo) or NaHCO3 (0.3 g.kg-1 body mass) over ...
Reents R - - 1995
The present study estimated variance components for test day records of somatic cell score and production traits. Data consisted of 235,100 test day observations recorded between 1986 and 1994 on lactations 1 to 3 of 15,922 Holstein cows from 143 herds. Records were considered as repeated observations within a lactation ...
R?s?nen L A - - 1995
OBJECTIVE: To study whether end products of 2 pathways of anaerobic energy metabolism, lactate and purines, that accumulate in the blood after intense exercise indicate any relation to exercise performance. DESIGN: Venous blood samples were taken within 1 and 15 minutes after a trotting race of 2,100 m. ANIMALS: 16 ...
Phillips S M - - 1995
A short-term training model previously shown to result in a tighter metabolic control in working muscle in the absence of an increase in mitochondrial potential was used to examine changes in lactate turnover. Lactate flux was studied before and after 10 days of cycle training [2 h/day at 59% maximal ...
Hassel B - - 1995
Cerebral formation of lactate via the tricarboxylic acid (TCA) cycle was investigated through the labeling of lactate from [2-13C]acetate and [1-13C]glucose as shown by 13C NMR spectroscopy. In fasted mice that had received [2-13C]acetate intravenously, brain lactate C-2 and C-3 were labeled at 5, 15, and 30 min, reflecting formation ...
Bangsbo J - - 1995
1. The present study examined how uptake of lactate and H+ in resting muscle is affected by blood flow, arterial lactate concentration and muscle metabolism. 2. Six males subjects performed intermittent arm exercise in two separate 32 min periods (Part I and Part II) and in one subsequent 20 min ...
Altemus M - - 1995
In the rat, lactation suppresses a variety of physiological responses to stress. We investigated whether stress-responsive neurohormonal systems are also restrained during breast feeding in humans. We chose treadmill exercise as a stressor because this stimulus produces an exercise intensity-dependent activation of the hypothalamic-pituitary-adrenal axis and the sympathomedullary system that ...
Ohkuwa T - - 1995
This investigation examined the reproducibility of salivary lactate measurement in long-distance runners following a 3000-m run and compared the salivary and blood lactate concentrations in sprinters and long-distance runners following a 400-m run. There was no significant difference in salivary and blood lactate between the first and second 3000-m run ...
MacRae H H - - 1995
This report describes the effects of 9 weeks of endurance-training on the relative rates of lactate removal via oxidation and gluconeogenesis in humans. Before and after training, eight subjects performed incremental (60 W plus 40 W every 6 min) exercise tests, while 14C-lactate was infused into one forearm vein and ...
Freund H - - 1995
Arterial blood lactate concentrations and pH were measured on seven black male sickle cell trait (SCT) carriers before, during and after incremental exhaustive bicycle exercise (25 W increments per minute) and compared with those of six control individuals of the same ethnic origin having a similar physical fitness level. The ...
Ghosh A K - - 1995
The heart rate (HR) and blood lactate response were studied on 26 senior national level boxers in competitive bouts to explore the aerobic-anaerobic metabolism as well as the training status of the players. The aerobic capacity (VO2 max) of the players were determined using graded running protocol on a treadmill. ...
Turner M J - - 1995
In an attempt to determine whether the lactate threshold (LT) is the result of a sudden increase in plasma epinephrine (Epi), eight healthy college-aged males (22.4 +/- 0.4 yr) were recruited to perform three cycle ergometer exercise tests. Each subject performed a graded exercise test (GXT) to determine LT, Epi ...
Ibanez J - - 1995
This study was designed to investigate the effect of an induced metabolic alkalosis on a 300 m sprinting time in six elite 400 m runners. The subjects competed as pairs, on two separate occasions, in a standard racing format, three hours after ingestion of either an alkaline (sodium citrate, 0.5 ...
Ryan C - - 1995
The formation of muscle glycogen from substrates other than glucose (glyconeogenesis) has now been demonstrated 1) from circulating lactate when this lactate is elevated and 2) from intramuscular substrate, which equilibrates with the products of local glucose metabolism but not with circulating lactate [Am. J. Physiol. 267 (Endocrinol. Metab. 30): ...
Putman C T - - 1995
The regulation of the active form of pyruvate dehydrogenase (PDHa) and related metabolic events were examined in human skeletal muscle during repeated bouts of maximum exercise. Seven subjects completed three consecutive 30-s bouts of maximum isokinetic cycling, separated by 4 min of recovery. Biopsies of the vastus lateralis were taken ...
Tolfrey K - - 1995
The aim of this study was to evaluate whether fixed blood lactate reference values of 2.5 and 4.0 mmol.1(-1) corresponded to the equivalent intensity of exercise in prepubertal and teenage boys, and men. Twenty six prepubertal boys (mean(sd) age) 11.1(0.4) years), 26 teenage boys (mean(sd) age 14.1(0.3) years), and 23 ...
Lewandowski E D - - 1995
The role of lactate as a source of pyruvate oxidation in supporting cardiac work, energetics, and formation of oxidative metabolites was examined in normal myocardium. 13C- and 31P-nuclear magnetic resonance (NMR) spectra were acquired from isolated rabbit hearts supplied 2.5 mM [3-13C]lactate or [3-13C]pyruvate with or without stimulation of pyruvate ...
Dandurand R J - - 1995
Mitochondrial diseases are a heterogeneous group of disorders in which it has been suggested that genetic defects in oxidative phosphorylation lead to specific alterations in exercise performance and lactate metabolism during exercise. To investigate this possibility, we evaluated pulmonary function tests, incremental exercise testing, and serial blood lactate levels in ...
Kim H S - - 1995
Alterations in cardiac function during prolonged submaximal exercise relative to lactate threshold (LT) were evaluated on 7 normal healthy males aged 30.3 +/- 5.7 years. Systolic time intervals were analyzed through simultaneous recordings of electrocardiogram, phonocardiogram, and impedance cardiogram at a paper speed of 50 mm/s. Determination of stroke volume ...
Grassi B - - 1995
The lower peak lactate accumulation in blood ([La(b)]p) at altitude may be associated with a reduced maximal glycolytic flux. Based on certain assumptions, the latter can be indirectly evaluated in vivo, during short supramaximal exercises, by measuring the maximal rate of lactate accumulation in blood (delta [La(b)]max). delta [La(b)]max was ...
Foster C - - 1995
The blood lactate profile (HLa-P) is an accepted method of evaluating athletes and providing a basis for the prescription of training intensity. For both logistic and public health reasons HLa-P is less than optimal. In this study we evaluate the relative velocity or the %HR-max, obtained during a training session, ...
Miyajima H - - 1995
Recurrent rhabdomyolysis due to decreased glycolysis occurred during strenuous exercise in patients with lactate dehydrogenase A subunit (LDH-A) deficiency. We report the features of oxidative metabolism of four patients from two families in whom the severity of the disease differed. Enzyme activities of muscle LDH were decreased to < 5% ...
Brouns F - - 1995
This study tested the hypothesis that a 3-week oral lactate supplementation affects postexercise blood lactate disappearance in untrained male subjects. Fifteen men were randomly assigned to either a lactate supplementation (n = 8) or a placebo (n = 7) treatment. During the treatment period they drank an oral lactate or ...
Johnson A T - - 1995
To test effects of respirator masks on maximum oxygen uptake, ventilation threshold, and lactate threshold, 14 subjects underwent incremental bicycle exercise with and without masks. There was a statistically significant difference in final oxygen consumption between the two conditions, but other results suggest that the physiological measure of maximum oxygen ...
Rainger J E - - 1995
The distribution of lactate between red blood cells (RBC) and plasma was examined at rest, during exercise and 30 min after exercise in six Standardbred horses. Lactate and water concentrations were measured in blood and plasma samples collected prior to exercise, during the last 15 s of each step of ...
Landgren B M - - 1995
A total of 20 breastfeeding women used progesterone-releasing vaginal rings for up to 12 months. The women were divided into two groups, one (n = 9) using rings with an initial release rate of 5 mg/24 h, the other (n = 11) with a release rate of 20 mg/24 h. ...
Durkot M J - - 1995
Severe lactic acidosis usually accompanies intense endurance exercise. It has been postulated that glycogen depletion working in concert with elevated muscle and plasma lactate levels lead to a concomitant reduction in pH. Their cumulative effect during prolonged physical exertion now leads to muscular fatigue and eventually limit endurance capacity. Therefore ...
Haas R H - - 1995
In an attempt to identify a possible defect of mitochondrial metabolism in Rett syndrome we studied 9 girls with typical Rett syndrome using a clinical protocol designed to identify disorders of oxidative metabolism. One girl, (RO) had marked lactic acidemia. Biochemical studies on samples from these patients included leukocyte pyruvate ...
Bouckaert J - - 1995
Nine male healthy and physically active volunteers performed four different exercise tests: an incremental load exercise test to exhaustion and a constant load exercise test of 15 min at 65% VO2max, both on the bicycle ergometer and on the treadmill. During the incremental exercise test, blood ammonia levels were significantly ...
Sadowsky S - - 1995
PURPOSE: Oxygen-enriched gases enable patients and healthy individuals to exercise submaximally with reduced lactate concentration, lower minute ventilation (VE), and less subjective stress compared to normoxia. These findings suggest that hyperoxia may raise the lactate accumulation threshold, also known as the anaerobic threshold (AT). METHODS: This study measured the anaerobic ...
Barron J T - - 1995
Vascular smooth muscle metabolism is characterized by substantial production of lactic acid even under fully oxygenated conditions. The role the aerobic production of lactate plays in the energetics of smooth muscle is obscure and was investigated in this study. Helical strips of porcine carotid arteries were incubated in medium containing ...
Williams B D - - 1995
We used a new stable isotope tracer approach incorporating muscle intracellular lactate enrichment to determine the flux of glucose/glucosyl toward lactate [i.e., nonoxidized pyruvate (Pyr) production (Pyrno)] in moderately trained cyclists exercising at approximately 80% (259 +/- 16 W; n = 6) and approximately 100% (341 +/- 9 W; n ...
Dugan M E - - 1995
BACKGROUND: The objective of this study was to investigate whether luminal perfusion with glutamine or with oxygenated glutamine solutions prevents endotoxin-induced changes in mucosal permeability. METHODS: Three 15-cm segments of distal ileum were isolated in anesthetized 21-day-old piglets (n = 4) and perfused (50 mL/h) with Ringer's lactate solution, Ringer's ...
Beaudeau F - - 1995
Data from a survey performed from 1986 to 1990 were analyzed to assess the effects of diseases on length of productive life of 3589 Holstein cows from 47 herds, using a proportional hazard model. The probability of a cow being culled, or hazard function, was supposed to be the product ...
Francaux M - - 1995
Tracers have been used extensively to study lactate metabolism in humans during rest and exercise. Nevertheless, quantification of in vivo lactate kinetics as measured by lactate tracers remains controversial and new data are necessary to clarify the issue. The present study has developed a simple kinetic model which does not ...
Pianosi P - - 1995
Blood concentrations of lactate normally increase during and after intense exercise as does the ratio of concentrations of lactate to pyruvate (L:P). Since there appear to be differences in blood lactate concentrations on exercise, in muscle metabolic enzyme activities, and in anaerobic capacity between children and adults, we speculated that ...
Stupnicki R - - 1995
Relationships between the postexercise values of blood lactate concentration, pH, oxygen uptake, heart rate, power output on the one hand, and the pre- and postexercise blood cortisol concentrations on the other, were studied in 74 male and 40 female athletes (wrestlers and senior and junior rowers), performing graded exercise of ...
Pokan R - - 1995
The correlation between the behaviour of the heart rate/work performance (fc/W) curve and blood lactate ([la]b) and plasma adrenaline/noradrenaline concentrations ([A]/[NA]) during incremental cycle ergometer exercise was investigated. A group of 21 male sports students was divided into two groups: group I, with a clear deflection of the fc/W curve; ...
Smekal G - - 1995
Metabolic and cardiorespiratory reactions were investigated during a sport-specific incremental field test (FT) for tennis and compared with a treadmill step test (TT) in a group of 13 trained male tennis players. In both the FT and the TT lactate acid (La), heart rate and oxygen uptake (VO2) were measured. ...
Jeukendrup A E - - 1994
In a cyclist, competing at national and international level, submaximal lactate concentrations were initially interpreted as improved endurance capacity. However, 2 weeks later, a test in which maximal lactate was measured showed that maximal lactate was decreased as well. Together with the complaints of deteriorating performance and subjective complaints of ...
Veneman T - - 1994
The brain usually depends almost exclusively on glucose for its energy requirements. During hypoglycemia associated with prolonged fasting or strenuous exercise, circulating ketone-body and lactate levels increase several-fold; in both situations, certain signs and symptoms of hypoglycemia are diminished. Therefore, to test the hypothesis that hyperketonemia or hyperlacticacidemia of the ...
de Haan H H - - 1994
During severe oxygen shortage, the fetal brain resorts to anaerobic metabolism and ATP becomes catabolized. High levels of nucleosides, hypoxanthine, and xanthine (ATP catabolites) in cerebrospinal fluid (CSF) may therefore be associated with increased neonatal neurologic morbidity. In 22 fetal lambs (3 to 5 d after surgery, gestational age 123.5 ...
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