Mammalian metabolite flux rates in a teleost: lactate and glucose turnover in tuna

1986 ◽  
Vol 250 (3) ◽  
pp. R452-R458 ◽  
Author(s):  
J. M. Weber ◽  
R. W. Brill ◽  
P. W. Hochachka
Keyword(s):  
Blood Lactate ◽  
Turnover Rate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Lactate Clearance ◽  
Glucose Turnover ◽  
Skipjack Tuna ◽  
Turnover Rates ◽  
Total Blood ◽  
Lactate Turnover

Lactate and glucose turnover rates were measured by bolus injection of [U-14C]lactate and [6-3H]glucose in cannulated lightly anesthetized skipjack tuna, Katsuwonus pelamis. Our goals were to find out whether the high rates of lactate clearance reported during recovery from burst swimming in tuna could be accounted for by high blood lactate fluxes; to extend the observed correlation between lactate turnover and lactate concentration in mammals to a nonmammalian system, and to assess the importance of lactate and glucose as metabolic fuels in tuna and to compare their flux rates with values reported for mammals. Measured lactate turnover rates ranged from 112 to 431 mumol X min-1 X kg-1 and were correlated with blood lactate concentration. Glucose turnover rate averaged 15.3 mumol X min-1 X kg-1. When correcting for body mass and temperature, skipjack tuna has at least as high or even higher lactate turnover rates than those recorded for mammals. Tuna glucose turnover rate is similar to that of mammals but much higher than levels found in other teleosts. Even the highest lactate turnover rate measured in tuna cannot fully account for the rate of blood lactate clearance observed during recovery, suggesting that some of the lactate produced in skeletal muscle must be metabolized in situ. After injection of [U-14C]lactate, less than 5% of the total blood activity was recovered in glucose, suggesting that the Cori cycle is not an important pathway of lactate metabolism in tuna.

scholarly journals In vivo lactate kinetics at rest and during recovery from exhaustive exercise in coho salmon (Oncorhynchus kisutch) and starry flounder (Platichthys stellatus)

1988 ◽  
Vol 135 (1) ◽  
pp. 119-131 ◽  
Author(s):  
C. L. Milligan ◽  
D. G. McDonald
Keyword(s):  
Blood Lactate ◽  
Turnover Rate ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Lactate Clearance ◽  
Turnover Rates ◽  
Platichthys Stellatus ◽  
Lactate Turnover ◽  
Lactate Levels ◽  
Blood Lactate Levels

A bolus injection of [14C]lactate was used to measure lactate turnover rates at rest and during recovery from exhaustive exercise in coho salmon (Oncorhynchus kisutch) and starry flounder (Platichthys stellatus). At rest, lactate turnover rate in salmon was almost double that in flounder (1.33 versus 0.76 mumol min-1 kg-1), which reflected the higher blood lactate level in salmon (1.00 versus 0.12 mmol l-1). From 2 to 4 h after exercise, when blood lactate levels were at their peak and constant, turnover rates were elevated in both species, though to a greater extent in salmon than in flounder (11.88 versus 2.27 mumol min-1 kg-1). Lactate concentration and turnover rate were linearly correlated in both species. The higher turnover rate in salmon was solely a consequence of the higher blood lactate levels since, at similar blood lactate concentrations, turnover rates in flounder and salmon were the same. Therefore, the lower blood lactate levels in flounder after exercise were not a consequence of higher turnover. In neither species was the turnover rate adequate to account for the rate of lactate clearance from the muscle, suggesting a large portion was retained within the muscle and metabolized in situ. Furthermore, following injection of [14C]lactate, greater than 80% of the total blood activity was recovered as lactate, indicating that little label was incorporated into other products (e.g. glucose). These data suggest that the Cori cycle plays a minimal role in the metabolism of lactate in salmon and flounder. Furthermore, at least in flounder, there was no correlation between the kinetics of lactate clearance and O2 consumption, suggesting that the classical concept of ‘O2 debt’ is not applicable in this species.

scholarly journals Lactate Clearance as a Predictive Marker of Mortality in Adult Intensive Care Unit

2020 ◽  
Vol 5 (2) ◽  
pp. 32-38
Author(s):  
Shirish Raj Joshi ◽  
Renu Gurung ◽  
Subhash Prasad Acharya ◽  
Bashu Dev Parajuli ◽  
Navindra Raj Bista
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Lactate Clearance ◽  
Icu Mortality ◽  
Adult Intensive Care Unit ◽  
Icu Admission ◽  
Significant Difference

Introduction: Lactate clearance has been widely investigated. Serial lactate concentrations can be used to examine disease severity and predict mortality in the intensive care unit. We investigated the diagnostic accuracy of lactate concentration and lactate clearance in predicting mortality in critically ill patients during the first 24 hours in Intensive Care Unit (ICU).Methods: It was a Prospective, observational study conducted in ICU. Sixty eight consecutive patients having blood lactate level >2 mmol/L were included irrespective of disease and postoperative status. We measured blood lactate concentration at ICU admission(H0), at six hours(H6), 12 hours(H12), and 24 hours(H24). Lactate clearance was measured for H0-H6, H0-H12 and H0-H24 time period.Results: ICU mortality was 33.8%. Lactate clearance was 15.80 ± 17.21% in survivors and 1.73±11% in non survivors for the H0-H6 (p = 0.001) and remained higher in survivors than in non survivors over the study period of 24 hours; 17.97±15 vs. -2.04±19.84% for H0-H12 and 27.40 ± 11.41% vs. -14.83 ± 26.84% for the H0-H24 period (p < 0.001 for each studied period). There was significant difference in lactate concentration (static) between survivors and non survivors during the course of initial 24 hours. The best predictor of ICU mortality was lactate clearance for the H0-H24 period (AUC =0.89; 95% CI 0.78-1.01). Logistic regression found that H0-H24 lactate clearance was independently correlated to a survival status (p = 0.005, OR = 0.922 and 95% CI 0.871-0.976).Conclusion: Blood lactate concentration and lactate clearance are both predictive for mortality during initial 24 hours of ICU admission.

Substrate-turnover interrelationships in fasting neonatal dogs

1980 ◽  
Vol 239 (4) ◽  
pp. E287-E287 ◽  
Keyword(s):  
Blood Glucose ◽  
Fasting Blood Glucose ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Glucose Turnover ◽  
Lactate Turnover ◽  
Lower Blood ◽  
Lactate Utilization ◽  
Blood Glucose Concentrations ◽  
The Relationship

Substrate-turnover relationships were determined in unanesthetized healthy fasted neonatal dogs during the first day of life. Pups were born at term by cesarean section to starved or control mothers. Pups born to starved mothers developed significantly lower blood glucose concentrations during neonatal fasting. In all pups, blood glucose concentrations during neonatal fasting. In all pups, blood glucose concentrations correlated to glucose utilization (r = 0.462, P < 0.001). Blood lactate concentration was significantly related to its turnover. The relationship between lactate turnover and lactate carbon appearance into glucose was significantly correlated. However, the relationship between lactate concentration and its carbon incorporation into glucose was only significant at 24 h of age in pups born to starved mothers. These data suggest that the neonatal dog is capable of regulating its glucose and lactate utilization by the availability of substrate. Because peripheral insulin levels correlated poorly to fasting blood glucose and glucose turnover; it is doubtful whether insulin secretion plays a significant role in fasting neonatal canine glucose homeostasis.

scholarly journals Quantitative Assessment of Blood Lactate in Shock: Measure of Hypoxia or Beneficial Energy Source

2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
David G. Levitt ◽  
Joseph E. Levitt ◽  
Michael D. Levitt
Keyword(s):  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Tca Cycle ◽  
Lactate Clearance ◽  
Tissue Hypoxia ◽  
Response To Therapy ◽  
Lactate Release ◽  
Liver And Kidney ◽  
Exercise Induced

Blood lactate concentration predicts mortality in critically ill patients and is clinically used in the diagnosis, grading of severity, and monitoring response to therapy of septic shock. This paper summarizes available quantitative data to provide the first comprehensive description and critique of the accepted concepts of the physiology of lactate in health and shock, with particular emphasis on the controversy of whether lactate release is simply a manifestation of tissue hypoxia versus a purposeful transfer (“shuttle”) of lactate between tissues. Basic issues discussed include (1) effect of nonproductive lactate-pyruvate exchange that artifactually enhances flux measurements obtained with labeled lactate, (2) heterogeneous tissue oxygen partial pressure (Krogh model) and potential for unrecognized hypoxia that exists in all tissues, and (3) pathophysiology that distinguishes septic from other forms of shock. Our analysis suggests that due to exchange artifacts, the turnover rate of lactate and the lactate clearance are only about 60% of the values of 1.05 mmol/min/70 kg and 1.5 L/min/70 kg, respectively, determined from the standard tracer kinetics. Lactate turnover reflects lactate release primarily from muscle, gut, adipose, and erythrocytes and uptake by the liver and kidney, primarily for the purpose of energy production (TCA cycle) while the remainder is used for gluconeogenesis (Cori cycle). The well-studied physiology of exercise-induced hyperlactatemia demonstrates massive release from the contracting muscle accompanied by an increased lactate clearance that may occur in recovering nonexercising muscle as well as the liver. The very limited data on lactate kinetics in shock patients suggests that hyperlactatemia reflects both decreased clearance and increased production, possibly primarily in the gut. Our analysis of available data in health and shock suggests that the conventional concept of tissue hypoxia can account for most blood lactate findings and there is no need to implicate a purposeful production of lactate for export to other organs.

Enhanced efficiency of lactate removal after endurance training

1990 ◽  
Vol 68 (3) ◽  
pp. 1053-1058 ◽  
Author(s):  
C. M. Donovan ◽  
M. J. Pagliassotti
Keyword(s):  
Endurance Training ◽  
Blood Lactate ◽  
Specific Activity ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Consistent Difference ◽  
Blood Concentrations ◽  
Lactate Turnover ◽  
Lactate Removal ◽  
Lactate Infusion

The effects of endurance training (running 1 h/day at 40 m/min, 10% grade) on net lactate removal at various lactate concentrations were assessed in resting rats by use of constant exogenous lactate infusion (0, 69.3, 123.6, and 175.0 mumol.kg-1.min-1). No consistent difference in resting lactate concentrations, 1.17 +/- 0.09 mM, was observed between control and trained animals with no exogenous infusion of lactate. With increasing lactate infusion rates, control animals demonstrated a twofold greater increase in blood lactate concentration (range 1.2-11.4 mM) compared with trained animals (range 1.0-5.5 mM). This response resulted from a more rapid rise in net lactate removal with changes in blood lactate concentration for trained animals. The estimated maximal reaction velocity for net lactate removal in trained animals was 19% lower than in control animals; however, the Michaelis-Menten constant was greater than 66% lower in trained animals (4 mM) compared with controls (12 mM). Control animals also demonstrated a twofold greater increase in lactate concentration as a function of the tracer-estimated lactate turnover. The ratio of 14CO2 yield to lactate specific activity as a function of total tracer removal was not significantly different between groups, suggesting that the relative contributions of oxidation and gluconeogenesis to lactate removal were similar for both groups. At blood concentrations greater than 1 mM, trained animals achieve higher rates of lactate removal for any given lactate concentration.

Endurance training affects lactate clearance, not lactate production

1983 ◽  
Vol 244 (1) ◽  
pp. E83-E92 ◽  
Author(s):  
C. M. Donovan ◽  
G. A. Brooks
Keyword(s):  
Endurance Training ◽  
Blood Lactate ◽  
Lactate Production ◽  
Lactate Clearance ◽  
Metabolic Clearance ◽  
Lactate Metabolism ◽  
Turnover Rates ◽  
Lactate Turnover ◽  
Metabolic Conditions ◽  
Lactate Levels

Primed-continuous infusion of [2-3H]- and [U-14C]lactate was used to study the effects of endurance training (running 2 h/day at 29.4 m/min up a 15% gradient) on lactate metabolism in rats. Measurements were made under three metabolic conditions: rest (Re), easy exercise (EE, 13.4 m/min, 1% gradient) and hard exercise (HE, 26.8 m/min, 1% gradient). Blood lactate levels in trained animals increased from 1.0 +/- 0.09 mM in Re to 1.64 +/- 0.21 in EE and 2.66 +/- 0.38 in HE. Control animals also demonstrated an increase in blood lactate with increasing work rate, but values were 1.93 +/- 0.21 and 4.62 +/- 0.57 mM at EE and HE, respectively. Lactate turnover rates (RtLA) measured with [U-14C]lactate increased from 214.0 +/- 17.0 mumol.kg-1.min-1 in Re to 390.3 +/- 31.6 in EE and 518.1 +/- 56.4 in HE. No significant differences in RtLA were observed between controls and trained animals under any condition. Identical relationships between RtLA and exercise or training were obtained with [2-3H]lactate; however, the values obtained were consistently 90% higher than those observed with [U-14C]lactate. Metabolic clearance rate (MCR) for 14C was not significantly different in Re between controls and trained animals (180.6 +/- 27.7 ml.kg-1.min-1). Metabolic clearance of lactate in trained animals was 37 and 107% greater than in controls during EE and HE, respectively. Results indicate that the effect of endurance training is not on production of lactate but on its clearance from the blood.

Lactate kinetics in exercising Thoroughbred horses: regulation of turnover rate in plasma

1987 ◽  
Vol 253 (6) ◽  
pp. R896-R903 ◽  
Author(s):  
J. M. Weber ◽  
W. S. Parkhouse ◽  
G. P. Dobson ◽  
J. C. Harman ◽  
D. H. Snow ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Turnover Rate ◽  
Lactate Concentration ◽  
Minor Role ◽  
Rate Variation ◽  
Plasma Lactate ◽  
Turnover Rates ◽  
Thoroughbred Racehorses ◽  
Lactate Turnover ◽  
Plasma Lactate Concentration

Plasma lactate turnover rate of Thoroughbred racehorses was measured by bolus injection of [U-14C]lactate at rest and two levels of submaximal treadmill exercise (3-4 m/s trot, 6% incline, and 6.5 m/s horizontal canter). Our goals were 1) to determine the relative effects of changes in cardiac output and in plasma lactate concentration on turnover rate [using cardiac output data from Weber et al. (28)] and 2) to assess the importance of lactate as a metabolic fuel in a trained animal athlete. Lactate turnover rates were 9.3 mumol.min-1.kg-1 (rest), 75.9 mumol.min-1.kg-1 at the beginning of the trot protocol [45% maximum O2 uptake (VO2max)], 50.3 mumol.min-1.kg-1 later in the same protocol (50% VO2max), and 66.1 mumol.min-1.kg-1 during the canter protocol (55% VO2max). Both changes in cardiac output and in plasma lactate concentration had a significant effect on turnover rate. Variation in plasma lactate fluxes of Thoroughbreds during exercise follows the standard mammalian pattern, but this substrate only plays a minor role as an oxidizable fuel in horses. The oxidation of plasma lactate accounts for less than 5% of metabolic rate (VO2) during submaximal work. Adjustments in cardiac output and in metabolite concentration represent, respectively, the coarse and fine controls for the regulation of plasma metabolite turnover rate.

scholarly journals Is Low-Frequency Electrical Stimulation a Tool for Recovery after a Water Rescue? A Cross-Over Study with Lifeguards

2020 ◽  
Vol 17 (16) ◽  
pp. 5854
Author(s):  
Roberto Barcala-Furelos ◽  
Alicia González-Represas ◽  
Ezequiel Rey ◽  
Alicia Martínez-Rodríguez ◽  
Anton Kalén ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Blood Lactate ◽  
Enhanced Recovery ◽  
Lactate Concentration ◽  
Low Frequency ◽  
Blood Lactate Concentration ◽  
Lactate Clearance ◽  
Perceived Effort ◽  
Water Rescue ◽  
Recovery Protocols

This study aimed to evaluate the degree to which transcutaneous electrical stimulation (ES) enhanced recovery following a simulated water rescue. Twenty-six lifeguards participated in this study. The rescue consisted of swimming 100 m with fins and rescue-tube: 50 m swim approach and 50 m tow-in a simulated victim. Blood lactate clearance, rated perceived effort (RPE), and muscle contractile properties were evaluated at baseline, after the water rescue, and after ES or passive-recovery control condition (PR) protocol. Tensiomiography, RPE, and blood lactate basal levels indicated equivalence between both groups. There was no change in tensiomiography from pre to post-recovery and no difference between recovery protocols. Overall-RPE, legs-RPE and arms-RPE after ES (mean ± SD; 2.7 ± 1.53, 2.65 ± 1.66, and 2.30 ± 1.84, respectively) were moderately lower than after PR (3.57 ± 2.4, 3.71 ± 2.43, and 3.29 ± 1.79, respectively) (p = 0.016, p = 0.010, p = 0.028, respectively). There was a significantly lower blood lactate level after recovery in ES than in PR (mean ± SD; 4.77 ± 1.86 mmol·L−1 vs. 6.27 ± 3.69 mmol·L−1; p = 0.045). Low-frequency ES immediately after a water rescue is an effective recovery strategy to clear out blood lactate concentration.

The influence of execution speed on blood lactate concentration in strength training protocol in bench press exercise

2020 ◽  
Vol 19 (1) ◽  
pp. 32
Author(s):  
Gustavo Taques Marczynski ◽  
Luís Carlos Zattar Coelho ◽  
Leonardo Emmanuel De Medeiros Lima ◽  
Rodrigo Pereira Da Silva ◽  
Dilmar Pinto Guedes Jr ◽  
...  
Keyword(s):  
Strength Training ◽  
Blood Lactate ◽  
Bench Press ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
The Third ◽  
Fast Speed ◽  
Work Volume ◽  
Execution Speed ◽  
Training Protocol

The aim of this study was to analyze the influence of two velocities of execution relative to blood lactate concentration in strength training exercise until the momentary concentric failure. Fifteen men (29.1 ± 5.9 years), trained, participated in the experiment. The volunteers performed three bench press sessions, with an interval of 48 hours between them. At the first session, individuals determined loads through the 10-12 RMs test. In the following two sessions, three series with 90 seconds of interval were performed, in the second session slow execution speed (cadence 3030) and later in the third session fast speed (cadence 1010). For statistical analysis, the Student-T test was used for an independent sample study and considered the value of probability (p) ≤ 0.05 statistically significant. By comparing the number of repetitions and time under tension of the two runs, all series compared to the first presented significant reductions (p < 0.05). The total work volume was higher with the fast speed (p < 0.05). The study revealed that rapid velocities (cadence 1010) present a higher concentration of blood lactate when compared to slow runs (cadence 3030). The blood lactate concentration, in maximum repetitions, is affected by the speed of execution.Keywords: resistance training, cadence, blood lactate.

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