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.

Lack of Association between Indices of Vitamin B1, B2, and B6, Status and Exercise-Induced Blood Lactate in Young Adults

1993 ◽  
Vol 3 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Mikael Fogelholm ◽  
Inkeri Ruokonen ◽  
Juha T. Laakso ◽  
Timo Vuorimaa ◽  
Jaakko-Juhani Himberg
Keyword(s):  
Glutathione Reductase ◽  
Blood Lactate ◽  
Aspartate Aminotransferase ◽  
Lactate Concentration ◽  
Vitamin B1 ◽  
Blood Lactate Concentration ◽  
Vitamin B ◽  
Physically Active ◽  
Vitamin Status ◽  
Exercise Induced

By means of a 5-week vitamin B-complex .supplementation, associations between indices of vitamin B1, B2, and B6, status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18–32 yrs), were randomized into vitamin (n=22) and placebo (n=20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p<0.0001) after supplementation: transketolase decreased from l. 16 (1.14–1.18) (mean and 95% confidence interval) to 1.08 (1.06–1.10); glutathione reductase decreased from 1.33 (1.28–1.39) to 1 .I4 (1.1 1–1.17); and aspartate aminotransferase decreased from 2.04 (1.94–2.14) to 1.73 (1.67–1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.

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.

Effect of endurance training on activators of glycolysis in muscle during exercise

1994 ◽  
Vol 76 (2) ◽  
pp. 846-852 ◽  
Author(s):  
C. Duan ◽  
W. W. Winder
Keyword(s):  
Endurance Training ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration ◽  
Quadriceps Muscle ◽  
Muscle Lactate ◽  
Cyclic Monophosphate ◽  
Lactate Levels ◽  
Exercise Induced

Endurance training attenuates exercise-induced increases in blood lactate at the same submaximal work rate. Three intramuscular compounds that influence muscle lactate production were measured in fasted non-trained (NT) and endurance-trained (T) rats. The T rats were subjected to a progressive endurance-training program. At the end of the program (11 wk), they were running 2 h/day at 31 m/min up a 15% grade 5 days/wk. NT and T rats were fasted for 24 h and then anesthetized (pentobarbital, iv) at rest or after running for 30 min at 21 m/min (15% grade). Blood lactate levels were significantly lower in the T rats than in the NT rats after 30 min of running (2.3 +/- 0.2 vs. 3.9 +/- 0.2 mM). The lower blood lactate concentration was accompanied by lower plasma epinephrine (2.8 +/- 0.4 vs. 6.0 +/- 0.8 nM), adenosine 3′, 3′,5′-cyclic monophosphate (0.36 +/- 0.02 vs. 0.50 +/- 0.03 pmol/mg), mg), glucose 1,6-diphosphate (26 +/- 2 vs. 40 +/- 5 pmol/mg), and fructose 2,6-diphosphate (3.2 +/- 0.2 vs. 4.3 +/- 0.3 pmol/mg) in white quadriceps muscle in T than in NT rats. Red quadriceps muscle glucose 1,6-diphosphate and adenosine 3′,5′-cyclic monophosphate were also lower in T than in NT rats. These adaptations may be responsible in part for the lower exercise-induced blood lactate in fasted rats as a consequence of endurance training.

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.

Early adaptations in blood substrates, metabolites, and hormones to prolonged exercise training in man

1991 ◽  
Vol 69 (8) ◽  
pp. 1222-1229 ◽  
Author(s):  
H. J. Green ◽  
S. Jones ◽  
M. Ball-Burnett ◽  
I. Fraser
Keyword(s):  
Uric Acid ◽  
Exercise Training ◽  
Blood Lactate ◽  
Prolonged Exercise ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Exercise Session ◽  
Average Intensity ◽  
Exercise Induced ◽  
Male Subjects

This study was designed to investigate the effect of short-term, submaximal training on changes in blood substrates, metabolites, and hormonal concentrations during prolonged exercise at the same power output. Cycle training was performed daily by eight male subjects ([Formula: see text], [Formula: see text]) for 10–12 days with each exercise session lasting for 2 h at an average intensity of 59% of [Formula: see text]. This training protocol resulted in reductions (p < 0.05) in blood lactate concentration (mM) at 15 min (2.96 ± 0.46 vs. 1.73 ± 0.23), 30 min (2.92 ± 0.46 vs. 1.70 ± 0.22), 60 min (2.96 ± 0.53 vs. 1.72 ± 0.29), and 90 min (2.58 ± 1.3 vs. 1.62 ± 0.23) of exercise. The reduction in blood lactate was also accompanied by lower (p < 0.05) concentrations of both ammonia and uric acid. Similarly, following training lower concentrations (p < 0.05) were observed for blood β-hydroxybutyrate (60 and 90 min) and serum free fatty acids (90 min). Blood glucose (15 and 30 min) and blood glycerol (30 and 60 min) were higher (p < 0.05) following training, whereas blood alanine and pyruvate were unaffected. For the hormones insulin, glucagon, epinephrine, and norepinephrine, only epinephrine and norepinephrine were altered with training. For both of the catecholamines, the exercise-induced increase was blunted (p < 0.05) at both 60 and 90 min. As indicated by the changes in blood lactate, ammonia, and uric acid, a depression in glycolysis and IMP formation is suggested as an early adaptive response to prolonged submaximal exercise training.Key words: exercise, training, blood metabolites, substrates, hormones.

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.

scholarly journals Acute inhibition of ATP-sensitive K+ channels impairs skeletal muscle vascular control in rats during treadmill exercise

2015 ◽  
Vol 308 (11) ◽  
pp. H1434-H1442 ◽  
Author(s):  
Clark T. Holdsworth ◽  
Steven W. Copp ◽  
Scott K. Ferguson ◽  
Gabrielle E. Sims ◽  
David C. Poole ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Blood Lactate ◽  
Treadmill Exercise ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Vascular Conductance ◽  
Hindlimb Muscle ◽  
Exercise Induced

The ATP-sensitive K+ (KATP) channel is part of a class of inward rectifier K+ channels that can link local O2 availability to vasomotor tone across exercise-induced metabolic transients. The present investigation tested the hypothesis that if KATP channels are crucial to exercise hyperemia, then inhibition via glibenclamide (GLI) would lower hindlimb skeletal muscle blood flow (BF) and vascular conductance during treadmill exercise. In 27 adult male Sprague-Dawley rats, mean arterial pressure, blood lactate concentration, and hindlimb muscle BF (radiolabeled microspheres) were determined at rest ( n = 6) and during exercise ( n = 6–8, 20, 40, and 60 m/min, 5% incline, i.e., ∼60–100% maximal O2 uptake) under control and GLI conditions (5 mg/kg intra-arterial). At rest and during exercise, mean arterial pressure was higher (rest: 17 ± 3%, 20 m/min: 5 ± 1%, 40 m/min: 5 ± 2%, and 60 m/min: 5 ± 1%, P < 0.05) with GLI. Hindlimb muscle BF (20 m/min: 16 ± 7%, 40 m/min: 30 ± 9%, and 60 m/min: 20 ± 8%) and vascular conductance (20 m/min: 20 ± 7%, 40 m/min: 33 ± 8%, and 60 m/min: 24 ± 8%) were lower with GLI during exercise at 20, 40, and 60 m/min, respectively ( P < 0.05 for all) but not at rest. Within locomotory muscles, there was a greater fractional reduction present in muscles comprised predominantly of type I and type IIa fibers at all exercise speeds ( P < 0.05). Additionally, blood lactate concentration was 106 ± 29% and 44 ± 15% higher during exercise with GLI at 20 and 40 m/min, respectively ( P < 0.05). That KATP channel inhibition reduces hindlimb muscle BF during exercise in rats supports the obligatory contribution of KATP channels in large muscle mass exercise-induced hyperemia.

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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