Relation between lactic acid and base excess during muscular exercise

2018 ◽  
Vol 118 (4) ◽  
pp. 863-864
Author(s):  
Dieter Böning ◽  
Norbert Maassen
Keyword(s):  
Lactic Acid ◽  
Base Excess ◽  
Muscular Exercise ◽  
Acid And Base

scholarly journals Chemocatalytic Production of Lactates from Biomass-Derived Sugars

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Heng Zhang ◽  
Yulin Hu ◽  
Liying Qi ◽  
Jian He ◽  
Hu Li ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Heterogeneous Catalysts ◽  
Catalytic Performance ◽  
Green Solvents ◽  
Separation And Purification ◽  
Sustainable Resources ◽  
Base Catalysts ◽  
Heterogeneous Catalytic ◽  
Acid And Base ◽  
Relative Separation

In recent decades, a great deal of attention has been paid to the exploration of alternative and sustainable resources to produce biofuels and valuable chemicals, with aims of reducing the reliance on depleting confined fossil resources and alleviating serious economic and environmental issues. In line with this, lignocellulosic biomass-derived lactic acid (LA, 2-hydroxypropanoic acid), to be identified as an important biomass-derived commodity chemical, has found wide applications in food, pharmaceuticals, and cosmetics. In spite of the current fermentation of saccharides to produce lactic acid, sustainability issues such as environmental impact and high cost derived from the relative separation and purification process will be growing with the increasing demands of necessary orders. Alternatively, chemocatalytic approaches to manufacture LA from biomass (i.e., inedible cellulose) have attracted extensive attention, which may give rise to higher productivity and lower costs related to product work-up. This work presents a review of the state-of-the-art for the production of LA using homogeneous, heterogeneous acid, and base catalysts, from sugars and real biomass like rice straw, respectively. Furthermore, the corresponding bio-based esters lactate which could serve as green solvents, produced from biomass with chemocatalysis, is also discussed. Advantages of heterogeneous catalytic reaction systems are emphasized. Guidance is suggested to improve the catalytic performance of heterogeneous catalysts for the production of LA.

scholarly journals Production of lactic acid from cellulose using solid catalyst

2019 ◽  
Vol 268 ◽  
pp. 07006 ◽  
Author(s):  
Sujitra Doungsri ◽  
P. Rattanaphanee ◽  
Aatichat Wongkoblap
Keyword(s):  
Lactic Acid ◽  
Batch Reactor ◽  
Nitrogen Pressure ◽  
Reaction Pathways ◽  
Solid Catalyst ◽  
One Pot ◽  
Solid Catalysts ◽  
Platform Chemicals ◽  
Acid And Base ◽  
The One

Lactic acid (LA), one of the important biomass derived platform chemicals, has been used in food and chemical industries, especially in biodegradable polymer as polylactic acid (PLA). The aim of this work is to study the one-pot production of LA from cellulose by using different solid catalysts. The reaction was conducted in a high pressure batch reactor and the catalyst used in this study were ZrO2 and Al2O3. The reaction was carried out at temperature of 200oC for 6 hr. and under nitrogen pressure of 1 MP. It was found that the production yield of LA were 8.02% and 6.63%, when the ZrO2 and Al2O3 catalysts were used respectively. The result indicated that the ZrO2 may effect on the LA production because of the acid and base sites of the ZrO2. Therefore, the reaction pathways for conversion of cellulose into lactic acid have been investigated, and developed the new conditions to achieve the higher yield.

SODIUM, POTASSIUM, AND LACTIC ACID AFTER MUSCULAR EXERCISE IN THE RAT

1958 ◽  
Vol 36 (1) ◽  
pp. 1193-1201
Author(s):  
F. A. Sréter ◽  
Sydney M. Friedman
Keyword(s):  
Lactic Acid ◽  
Blood Sugar ◽  
Linear Correlation ◽  
The Other ◽  
Muscular Exercise ◽  
Sodium Potassium ◽  
Standard Time ◽  
Old Rats ◽  
Severe Exercise ◽  
Definite Correlation

Untrained young rats were exercised on a treadmill for a standard time at different speeds. A linear correlation between the intensity of the exercise and the degree of plasma [K] rise was observed. On the other hand, exercise at standard speed for varying durations was found to cause an increase in plasma [K] only during the early stages of the exercise. A fall in plasma [Na] was a constant accompaniment of exercise but no definite correlation to either intensity or duration was found. Lactic acid rose only with relatively severe exercise or with excitement. Blood sugar did not vary. Old rats responded to even mild exercise with a marked [K] shift accompanied by a well-defined rise in lactic acid.

scholarly journals Muscular exercise, lactic acid, and the supply and utilisation of oxygen.—Part XIII. The gaseous exchanges of restricted muscular exercise in man

1926 ◽  
Vol 99 (695) ◽  
pp. 155-166 ◽  
Keyword(s):  
Lactic Acid ◽  
Recovery Process ◽  
The Body ◽  
Muscular Exercise ◽  
Considerable Proportion ◽  
Active Muscle ◽  
A Value ◽  
Maximum Value ◽  
Severe Exercise ◽  
Type Of Exercise

The type of exercise studied in former papers of this series involves the activity of the body as a whole. The characteristic of all such forms of exercise is the free and vigorous movement of nearly all the muscles in the body. Since nearly all the muscles were in activity and behaving in a similar way it was more easy to compare their behaviour with that of an isolated muscle, and in previous papers it has been shown how closely the phenomena of muscular exercise in the body as a whole resemble those accompanying severe exercise in the isolated muscle. As far as concerns the observations described in the succeeding pages, the most pertinent conclusions of the former papers are as follows: (1) Provided that the exercise was not too severe, there occurred what has been called a steady state, in which recovery balanced breakdown in a manner analogous to that shown by Fletcher to occur in isolated frog’s muscle; (2) in severe exercise a considerable proportion of the energy employed is derived, not from contemporary oxidation, but by lactic acid formation on what may be called a “credit” of oxygen secured on the oxidation occurring in the recovery process later; (3) the most severe exercise can be maintained only for about 30 seconds, which corresponds to the time when the lactic acid concentration in the active muscle, as measured by the magnitude of the oxygen debt, may reach a value of about 0·3 per cent., the maximum value found to occur in the isolated frog’s muscle.

SODIUM, POTASSIUM, AND LACTIC ACID AFTER MUSCULAR EXERCISE IN THE RAT

1958 ◽  
Vol 36 (11) ◽  
pp. 1193-1201 ◽  
Author(s):  
F. A. Sréter ◽  
Sydney M. Friedman
Keyword(s):  
Lactic Acid ◽  
Blood Sugar ◽  
Linear Correlation ◽  
The Other ◽  
Muscular Exercise ◽  
Sodium Potassium ◽  
Standard Time ◽  
Old Rats ◽  
Severe Exercise ◽  
Definite Correlation

Untrained young rats were exercised on a treadmill for a standard time at different speeds. A linear correlation between the intensity of the exercise and the degree of plasma [K] rise was observed. On the other hand, exercise at standard speed for varying durations was found to cause an increase in plasma [K] only during the early stages of the exercise. A fall in plasma [Na] was a constant accompaniment of exercise but no definite correlation to either intensity or duration was found. Lactic acid rose only with relatively severe exercise or with excitement. Blood sugar did not vary. Old rats responded to even mild exercise with a marked [K] shift accompanied by a well-defined rise in lactic acid.

scholarly journals d-Lactic acid-induced neurotoxicity in a calf model

2007 ◽  
Vol 293 (2) ◽  
pp. E558-E565 ◽  
Author(s):  
Saman Abeysekara ◽  
Jonathan M. Naylor ◽  
Andrew W. A. Wassef ◽  
Ulyana Isak ◽  
Gordon A. Zello
Keyword(s):  
Lactic Acid ◽  
Nervous Tissue ◽  
Base Excess ◽  
Random Order ◽  
Neurological Function ◽  
The Other ◽  
Gastrointestinal Disorders ◽  
Neurotoxic Effect ◽  
Short Bowel ◽  
Holstein Calves

-Lactic acidosis (DAC) occurs as a complication of short-bowel syndrome in humans and in a variety of other gastrointestinal disorders in monogastrics and ruminants. DAC is associated with signs of impaired central nervous system (CNS) function including ataxia and coma. The objective of this experiment was to determine whether either acidification of nervous tissue or d-lactic acid is responsible for decreased neurological function. Eight Holstein calves (32 ± 11 days, 70 ± 10 kg) were surgically catheterized with indwelling intravenous jugular and atlanto-occipital space cerebrospinal fluid (CSF) catheters and infused for 6 h in random order with isomolar dl-lactic acid (dl-LA), l-lactic acid (l-LA), hydrochloric acid (HCl), or saline. dl-LA induced ataxia after 4 h of infusion and produced the greatest obtunding of CNS function (at 7 h, score 8.0 ± 0.4), whereas the other infusions caused neither ataxia nor scores over 1.5 ( P < 0.01 from dl-LA). dl-LA induced significantly less acidemia than HCl (at 6 h pH 7.13 ± 0.06 and 7.00 ± 0.04, base excess −16 ± 1 and −23 ± 3 mmol/l, bicarbonate 11 ± 1 and 8 ± 1 mmol/l respectively, all P < 0.01) but greater than l-LA and saline ( P < 0.01). CSF changes followed a similar but less pronounced pattern. Although HCl infusion produced a severe acidemia and CSF acidosis, only minor effects on neurological function were evident suggesting that d-lactate has a direct neurotoxic effect that is independent of acidosis. Conversely, l-LA produced only minor neurological changes.

scholarly journals Muscular exercise, lactic acid and the supply and utilisation of oxygen.— Parts VII–VIII

1924 ◽  
Vol 97 (682) ◽  
pp. 155-176 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Body Weight ◽  
Lactic Acid ◽  
The Body ◽  
Muscular Exercise ◽  
Oxygen Intake ◽  
Carbon Dioxide Output ◽  
Long Time ◽  
The Times ◽  
Ventilation Of The Lungs

(A) The relation between oxygen intake and severity of exertion . — When muscular exercise commences, the ventilation of the lungs, the oxygen intake and the carbon dioxide output rise rapidly, in a period of about 2½ minutes, to values characteristic of the severity of the exercise; at these values they remain approximately constant. If the exercise be moderate, i. e ., if the oxygen intake does not approach the maximum for the subject investigated, then the exercise may be continued for a long time: the body is able, so to speak, to provide the energy required “out of income.” If, however, the effort be excessive, the condition of exercise is not stable, the ventilation, the oxygen intake and the carbon dioxide output tend to attain their maximum values, and fatigue and exhaustion gradually or rapidly set in. The relation between these quantities and the magnitude of the effort made is clearly shown in Table I, especially in the series of 14 experiments made on A. V. H. running; at speeds from 2·86 to 4·7 metres per second. These results are plotted as double circles in fig. 1; the other points shown are the results obtained with S., W., and J. (who have approximately the same body-weight and build as A. V. H.), and with C. N. H. L. and H. L. (who are lighter). The observations on the two latter have been “reduced” to the same body-weight as A. V. H. before plotting. The running was on an open-air grass track, about 90 metres round, the speed being kept constant by an observer calling the times of successive laps. In every case the collection of expired gases was preceded by a sufficient foreperiod of exercise (2½ minutes or more) to ensure that a steady condition was reached. The following conclusions may be drawn from these observations:— (1) At low speeds the ventilation is small and the respiratory quotient is low: the oxygen supply is adequate to the needs of the body, lactic acid does not accumulate, and a steady state is soon attained.

Muscular Exercise, Lactic Acid, and the Supply and Utilization of Oxygen

QJM ◽  
1923 ◽  
Vol os-16 (62) ◽  
pp. 135-171 ◽  
Author(s):  
A. V. Hill ◽  
H. Lupton
Keyword(s):  
Lactic Acid ◽  
Muscular Exercise

scholarly journals Muscular exercise, lactic acid, and the supply and utilisation of oxygen. —Part XI. Pulse rate and oxygen intake during the early stages of recovery from severe exercise

1925 ◽  
Vol 98 (692) ◽  
pp. 468-479 ◽  
Keyword(s):  
Lactic Acid ◽  
Pulse Rate ◽  
The Body ◽  
Muscular Exercise ◽  
Circulation Rate ◽  
Oxygen Intake ◽  
Appreciable Change ◽  
Early Stages ◽  
Rate Of Increase ◽  
Severe Exercise

At the commencement of muscular exercise the oxygen intake and the pulse rate increase rapidly, but soon attain a steady value depending on the severity of the exertion. In strenuous exercise the intake of oxygen, although large, may not be sufficient to effect the oxidative removal of all the lactic acid formed, and the body goes into “oxygen debt.” During the recovery, therefore, from severe exercise, as opposed to that from mild exercise, the rate of fall of the oxygen intake is less rapid than was its rate of increase during the first minute or so of exercise. We find a condition in which the oxygen intake is determined, not by the contemporary requirement of the body in respect of the exercise which it is taking at the moment, but by a “debt” which was incurred during a previous period. At the end of several minutes of violent effort there is a considerable need of oxygen, which is not satisfied completely for a comparatively long time. Thirty seconds after the end of such exercise the need for oxygen is presumably nearly as great as it was during the exertion itself. The fall in the oxygen intake, therefore, which occurs immediately at the end of exercise is determined, not by any appreciable change in the requirement of the body for oxygen, but rather by an alteration in the mechanism by which it can be supplied. The immediate fall, in fact, of the oxygen intake must be credited largely to a change in the circulation rate of the blood, determined may be by the abrupt cessation of bodily movement, and not to any sudden alteration in the need for oxygen. During the first few moments, therefore, after exercise ends, when the oxygen requirement is still high, we may regard the oxygen intake as some measure of the circulation rate of the blood, and it is natural to compare it with the only other factor which can be continuously recorded for the circulation, namely, with the pulse rate. The simultaneous determination of the pulse rate and of the oxygen intake, during the early stages of recovery from severe exercise, has been made in the experiments to be described.

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