Effect of dichloroacetate on lactate concentration in exercising humans

1989 ◽  
Vol 66 (2) ◽  
pp. 591-597 ◽  
Author(s):  
F. Carraro ◽  
S. Klein ◽  
J. I. Rosenblatt ◽  
R. R. Wolfe
Keyword(s):  
Dehydrogenase Activity ◽  
Pyruvate Dehydrogenase ◽  
Tissue Oxygenation ◽  
Lactate Concentration ◽  
Bicycle Ergometer ◽  
Plasma Lactate ◽  
Exercise Load ◽  
Plasma Lactate Concentration ◽  
Oxidation Of Glucose ◽  
Exercise In Humans

The precise mechanism responsible for the increase in plasma lactate concentration during exercise in humans is not known. We have used dichloroacetate to test the hypothesis that a limitation in pyruvate dehydrogenase activity is responsible for the rise in plasma lactate. Dichloroacetate stimulates the activity of pyruvate dehydrogenase, which is normally the regulatory enzyme in the oxidation of glucose when tissue oxygenation is adequate. Six subjects were studied twice according to a randomized, crossover protocol, involving one test with saline infusion and another with dichloroacetate infusion. Exercise load on a bicycle ergometer was increased progressively until exhaustion. Blood samples were drawn each minute throughout exercise and periodically throughout 120 min of recovery. Dichloroacetate significantly lowered the lactate concentration during exercise performed at less than 80% of the average maximal O2 consumption. The peak concentration of lactate at exhaustion was not affected by dichloroacetate treatment, but dichloroacetate did lower lactate concentration throughout recovery. These results suggest that a limitation in pyruvate dehydrogenase activity contributes to the increase in plasma lactate during submaximal exercise and recovery.

Deficiency of glycerol kinase (EC 2.7.1.30).

1983 ◽  
Vol 29 (4) ◽  
pp. 718-722 ◽  
Author(s):  
A Eriksson ◽  
S Lindstedt ◽  
L Ransnäs ◽  
L von Wendt
Keyword(s):  
Blood Glucose Concentration ◽  
Lactate Concentration ◽  
Glycerol Kinase ◽  
Bicycle Ergometer ◽  
Gas Chromatography Mass Spectrometry ◽  
Glycerol Concentration ◽  
Plasma Lactate ◽  
Cultured Fibroblasts ◽  
Plasma Lactate Concentration ◽  
Large Peak

Abstract We describe the case of a 10-year-old boy who had been admitted on several occasions with a diagnosis of gastroenteritis. He had been severely ill, and on one occasion lost consciousness. He had a metabolic acidosis on these occasions. Examination of the urine by gas chromatography-mass spectrometry showed a large peak, identified as glycerol. The concentration of glycerol in the urine was 40-280 mmol/L and the concentration in plasma about 2 mmol/L. He was subjected to a fast of 21 h, at the end of which he expressed feelings of discomfort and nausea, began vomiting, and became somnolent. During this period the blood glucose concentration was only slightly decreased, the plasma glycerol concentration increased to 4.9 mmol/L, and the plasma lactate concentration increased to 3.8 mmol/L. During work on a bicycle ergometer for 35 min (40 W) he complained of muscle pain and became nauseated, but there was no significant increase in the concentration of plasma glycerol. The activity of glycerol kinase (EC 2.7.1.30) in leukocytes and cultured fibroblasts was less than 1% of the value for healthy subjects.

Glucose and lactate kinetics after endotoxin administration in dogs.

1977 ◽  
Vol 232 (2) ◽  
pp. E180 ◽  
Author(s):  
R R Wolfe ◽  
D Elahi ◽  
J J Spitzer
Keyword(s):  
Lactate Concentration ◽  
Constant Infusion ◽  
Glucose Turnover ◽  
Metabolic Clearance ◽  
Plasma Lactate ◽  
Metabolic Clearance Rate ◽  
Metabolic Substrate ◽  
E Coli ◽  
Lactate Kinetics ◽  
Plasma Lactate Concentration

We studied the effects of E. coli endotoxin on the glucose and lactate kinetics in dogs by means of the primed constant infusion of [6(-3)H] glucose and Na-L-(+)-[U-14C] lactate. The infusion of endotoxin induced a transient hyperglycemic level, followed by a steady fall in plasma glucose to hypoglycemic levels. The rate of appearance (Ra) and the rate of disappearance (Rd) of glucose were both significantly elevated (P less than .05) for 150 min after endotoxin, after which neither differed from the preinfusion value. The metabolic clearance rate of glucose was significantly elevated at all times 30 min postendotoxin. By 30 min postendotoxin, Ra and Rd of lactate, plasma lactate concentration, and the percent of glucose turnover originating from lactate were significantly elevated and remained so for the duration of the experiment. We concluded that after endotoxin hypoglycemia developed because of an enhanced peripheral uptake of glucose and a failure of the liver to maintain an increased Ra of glucose. We also concluded that lactate became an important precursor for gluconeogenesis and an important metabolic substrate.

scholarly journals Effects of exercise on plasma lactic acid and body temperature in man, following a standardized meal

2018 ◽  
Vol 17 (2) ◽  
pp. 270-274
Author(s):  
Tesleem K Babalola ◽  
Udoh Utibe Abasi
Keyword(s):  
Lactic Acid ◽  
Body Temperature ◽  
Statistical Tests ◽  
Medical Science ◽  
Lactate Concentration ◽  
Bicycle Ergometer ◽  
Mean Value ◽  
Plasma Lactate ◽  
Post Exercise ◽  
Before And After

Background: The effects of exercise on plasma lactic acid level and body temperature following a standardized meal were carried out on 20 healthy young individuals (aged between 18 and 29 yrs.), consisting of 10 males and 10 females. The physical fitness of the subjects was determined measuring their blood pressure, pulse rate and other physical examinations.Methodology: Each subject was made to ride the bicycle ergometer for 6mins, at a rhythmic cadence of 50revolution/ min via 100beats metronome counts. Blood samples were collected before and after the exercise to analyze for the pre and post exercise plasma lactate levels. Pre and post-exercise values for body temperature were also measured. Statistical tests were carried out at 95% CI (P=0.05).Result: The result obtained showed that exercise causes a statistically significant increase (p< 0.05) in both plasma lactate concentration (from a pre-exercise mean value of 0.98 ±0.07mmol/L to post- exercise mean value of 2.84 ±0.21mmol/L) and body temperature (from a mean value of 36.45 ±0.130C before exercise to a mean value of 36.91 ±0.190C after exercise).Conclusion: There was a statistically significant increase in plasma lactateand body temperature because of exposure to exercise which is in line with findings from most previous studies.Bangladesh Journal of Medical Science Vol.17(2) 2018 p.270-274

Adrenergic blockade prevents endotoxin-induced increases in glucose metabolism

1988 ◽  
Vol 255 (5) ◽  
pp. E629-E635 ◽  
Author(s):  
D. M. Hargrove ◽  
G. J. Bagby ◽  
C. H. Lang ◽  
J. J. Spitzer
Keyword(s):  
Plasma Insulin ◽  
Lactate Concentration ◽  
Insulin Concentration ◽  
Adrenergic Blockade ◽  
Plasma Lactate ◽  
Glucose Kinetics ◽  
Plasma Insulin Concentration ◽  
Beta Adrenergic ◽  
Plasma Lactate Concentration ◽  
Adrenergic Antagonists

Combined alpha- and beta-adrenergic blockade was used to investigate the role of catecholamines in endotoxin-induced elevations in glucose kinetics. Glucose kinetics were measured before and for 4 h after the injection of endotoxin [100 micrograms/100 g body wt iv, 30% lethal dose (LD30) at 24 h]. Adrenergic blockade was achieved by the bolus injection of phentolamine and propranolol followed by their continuous infusion. Endotoxin-treated rats exhibited a transient hyperglycemia and sustained (greater than 4 h) increase in plasma lactate concentration, as well as elevated rates of glucose appearance (Ra, 83%), disappearance (Rd, 58%), recycling (160%), and metabolic clearance (23%). Adrenergic blockade prevented endotoxin-induced increases in plasma glucose concentration, Ra, Rd, and recycling but not glucose clearance. The increase in plasma lactate concentration was blunted by 35%. After 2 h, endotoxic animals infused with adrenergic antagonists developed hypoglycemia, which may have resulted from an increased plasma insulin concentration. The attenuation of elevated glucose turnover by adrenergic blockade in the endotoxin-treated animals was not due to a reduction in plasma glucagon level or differences in plasma insulin concentration. Administration of the alpha- or beta-adrenergic antagonists separately blunted but did not prevent endotoxin-induced changes in glucose kinetics, and therefore the efficacy of the adrenergic blockade could not be assigned to a single receptor class. These results indicate that catecholamines are important contributory factors to many of the early alterations in carbohydrate metabolism observed during endotoxemia.

Plasma lactate and ventilation thresholds in trained and untrained cyclists

1986 ◽  
Vol 60 (3) ◽  
pp. 777-781 ◽  
Author(s):  
J. Simon ◽  
J. L. Young ◽  
D. K. Blood ◽  
K. R. Segal ◽  
R. B. Case ◽  
...  
Keyword(s):  
Lactate Threshold ◽  
Minute Ventilation ◽  
Lactate Concentration ◽  
Work Rate ◽  
Plasma Lactate ◽  
Vo2 Max ◽  
Trained Subjects ◽  
Leg Cycling ◽  
Plasma Lactate Concentration ◽  
Removal Processes

Six trained male cyclists and six untrained sedentary men were studied to determine whether the plasma lactate threshold (PLT) and ventilation threshold (VT) occur at the same work rate in both fit and unfit populations. The PLT was determined from a marked increase in plasma lactate concentration ([La]) and VT from a nonlinear increase in expired minute ventilation (VE) during incremental leg-cycling tests; work rate was increased 30 W every 2 min until volitional exhaustion. The trained subjects' mean VO2 max (63.8 ml O2 X kg-1 X min-1) and VT (65.8% VO2 max) were significantly higher (P less than 0.05) than the untrained subjects' mean VO2max (35.5 ml O2 X kg-1 X min-1) and VT (51.4% VO2 max). The trained subjects' mean PLT (68.8% VO2 max) and VT did not differ significantly, but the untrained subjects' mean PLT (61.6% VO2 max) was significantly higher than their VT. The trained subjects' mean peak [La] (10.5 mmol X l-1) did not differ significantly from the untrained subjects' mean peak [La] (11.5 mmol X l-1). However, the time of appearance of the peak [La] during passive recovery was inversely related to VO2 max. These results suggest that variance in lactate diffusion and/or removal processes between the trained and untrained subjects may account in part for the different relationships between the VT and PLT in each population.

Diving and swimming performance of white whales, Delphinapterus leucas: an assessment of plasma lactate and blood gas levels and respiratory rates.

1997 ◽  
Vol 200 (24) ◽  
pp. 3091-3099 ◽  
Author(s):  
S A Shaffer ◽  
D P Costa ◽  
T M Williams ◽  
S H Ridgway
Keyword(s):  
High Speed ◽  
Swimming Performance ◽  
Lactate Concentration ◽  
Delphinapterus Leucas ◽  
Breath Hold ◽  
Plasma Lactate ◽  
Post Exercise ◽  
Test Platform ◽  
Plasma Lactate Concentration ◽  
Breath Hold Duration

The white whale Delphinapterus leucas is an exceptional diver, yet we know little about the physiology that enables this species to make prolonged dives. We studied trained white whales with the specific goal of assessing their diving and swimming performance. Two adult whales performed dives to a test platform suspended at depths of 5-300 m. Behavior was monitored for 457 dives with durations of 2.2-13.3 min. Descent rates were generally less than 2 m s-1 and ascent rates averaged 2.2-3 m s-1. Post-dive plasma lactate concentration increased to as much as 3.4 mmol l-1 (4-5 times the resting level) after dives of 11 min. Mixed venous PO2 measured during voluntary breath-holds decreased from 79 to 20 mmHg within 10 min; however, maximum breath-hold duration was 17 min. Swimming performance was examined by training the whales to follow a boat at speeds of 1.4-4.2 m s-1. Respiratory rates ranged from 1.6 breaths min-1 at rest to 5.5 breaths min-1 during exercise and decreased with increasing swim speed. Post-exercise plasma lactate level increased to 1.8 mmol l-1 (2-3 times the resting level) following 10 min exercise sessions at swimming speeds of 2.5-2.8 m s-1. The results of this study are consistent with the calculated aerobic dive limit (O2 store/metabolic rate) of 9-10 min. In addition, white whales are not well adapted for high-speed swimming compared with other small cetaceans.

The Effect of Glycemic Index on Plasma Glucose and Lactate Levels during Incremental Exercise

2000 ◽  
Vol 10 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Stephen R. Stannard ◽  
Martin W. Thompson ◽  
Janette C. Brand Miller
Keyword(s):  
Glycemic Index ◽  
Plasma Glucose ◽  
Glucose Concentration ◽  
Lactate Concentration ◽  
Incremental Exercise ◽  
Plasma Glucose Concentration ◽  
Plasma Lactate ◽  
Significant Difference ◽  
Plasma Lactate Concentration ◽  
Lactate Levels

Consumption of low glycemic index (GI) foods before submaximal endurance exercise may be beneficial to performance. To test whether this may also be true for high intensity exercise. 10 trained cyclists began an incremental exercise test to exhaustion 65 min after consuming equal carbohydrate portions of glucose (HGI), pasta (LGI), and a noncarbohydrate control (PL). Time to fatigue did not differ significantly (p = 0.05) between treatments. Plasma glucose concentration was significantly lower after LGI vs. HGI from 15 to 45 min of rest postprandial. During exercise, plasma glucose concentration was significantly lower after HGI vs. LGI from 200 W until exhaustion. Plasma lactate concentration following HGI was significantly higher than PL from 30 min of rest postprandial through to the end of the 200-W workload. Plasma lactate concentration following LGI was significantly lower than after HGI from 45 min of rest postprandial through to the end of the 100-W workload. At higher exercise intensities, there was no significant difference in plasma lactate levels between treatments. These findings suggest that a high GI carbohydrate meal (1 g/kg body wt) 65 min prior to exercise decreases plasma glucose and increases plasma lactate levels compared to a low GI meal, but not enough to be detrimental to incremental exercise performance.

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