Carbohydrate metabolism and muscular exercise

doi:10.1098/rspb.1939.0011

Cited by 12 publications

(3 citation statements)

References 6 publications

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“…This may account for our results, although Johnson et al (1969) reported that the antiketogenic effect of glucose was less 1-1 h after exercise than after fasting, but this may have been due to the dissimilar blood ketone body concentrations in the two experimental conditions. Courtice, Douglas & Priestley (1939) found that there was a prompt reduction in ketonuria if sugar was ingested 124 h after exercise, and The daily blood ketone body concentrations (mean + S.E. of mean) often non-athletic subjects after a 65 h fast.…”

Section: Discussionmentioning

confidence: 99%

The effects of alanine, glucose and starch ingestion on the ketosis produced by exercise and by starvation.

Koeslag¹,

Noakes²,

Sloan³

1982

The Journal of Physiology

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SUMMARY1. Several investigators have found that the development of post-exercise ketosis is not counteracted by glucose ingestion. Post-exercise ketosis might therefore have more in common with diabetic ketoacidosis than with starvational ketosis.2. The effects of ingesting 100 g ofglucose, alanine or starch were therefore studied in subjects rendered hyperketonaemic by prolonged running on a low carbohydrate diet, or by 65 h of starvation. These substances were also ingested by normal post-prandial subjects.3. The runners developed post-exercise ketosis (1I81 +S.D. 0-81 mmol/l), which was counteracted by alanine and glucose, but only minimally by starch.4. Fasting caused a variable ketosis (2-19 +S.D. 1-63 mmol/l), also counteracted by glucose and less by starch, but alanine caused vomiting.5. Glucose and alanine lowered the blood ketone body levels of the post-prandial subjects.6. The rising ketone body levels in starvation and after exercise were accompanied by simultaneous increases in the plasma insulin/glucagon ratios; in both, glucose ingestion increased the ratio further, while alanine decreased it.7. It is concluded that there is no essential difference between established post-exercise and starvational ketosis, and that the blood fuel-hormone changes do not correlate with the changes in blood ketone body concentration.

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Section: Discussionmentioning

confidence: 99%

The effects of alanine, glucose and starch ingestion on the ketosis produced by exercise and by starvation.

Koeslag¹,

Noakes²,

Sloan³

1982

The Journal of Physiology

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“…/min. (Tompkins, Sturgis, and Wearn, 1919;Lyman, Nicholls, and McCann, 1923;Cori and Buchwald, 1930;and Courtice, Douglas, and Priestley, 1939), but no explanation of this effect has been put forward.…”

Section: Methodsmentioning

confidence: 99%

The Effect on Respiration of Infusions of Adrenaline and Noradrenaline Into the Carotid and Vertebral Arteries in Man

Coles

Duff

Shepherd

et al. 1956

British Journal of Pharmacology and Chemotherapy

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Intravenous injections of adrenaline and noradrenaline in man cause a striking increase in the rate and depth of respiration. This is associated with a fall in the alveolar CO2 content and an increase in the respiratory minute volume. The hyperpnoea is abrupt in onset and does not appear to be accounted for by a general increase in metabolic rate (Whelan and Young, 1953).The present experiments were carried out in an attempt to determine if the stimulant effect of adrenaline and noradrenaline on respiration in man is the result of a direct action on the respiratory or other centre in the brain. METHODSThe subjects were patients on whom cerebral angiography was being carried out for diagnostic purposes. Following the first injection of contrast medium, an interval elapsed, while the films were developed and studied, before further injections were made. Advantage was taken of this interval to infuse small doses of adrenaline or noradrenaline and record their effects on respiration.The patients lay supine with the head extended. The respiratory movements were recorded by means of two stethographs, one around the chest and the other around the abdomen (Shepherd, 1951;Dornhorst and Leathart, 1952). These were connected to a volume recorder which traced the movements with an ink writer on a kymograph drum.Direct Infusion into the Common Carotid Artery. -Under local anaesthesia with 10-20 ml. of 1% (w/v) procaine, a needle, 9.5 cm. long and 2 mm. in external diameter with a short bevel, was inserted into the common carotid artery. The needle was connected to a mechanically-driven syringe by a length of polythene tubing. An infusion of 0.9% saline was maintained throughout at a rate of 4 ml./min. and was interrupted when required either for injection of contrast medium or for the infusion of adrenaline or noradrenaline solutions.

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“…Moreover, the lactic acid itself diffuses out of the cells to liberate more CO2 extracellularly and the gas can only escape through the lungs. Because of the preponderant contribution by the tissues, large increments in the respiratory production of CO2 may be observed, with only relatively -small changes in the CO2 content of serum (50).…”

Section: Overventilationmentioning

confidence: 99%

The Influence of Alterations in Acid-Base Balance Upon Transfers of Carbon Dioxide and Bicarbonate in Man 1

Rosenbaum¹

1942

J. Clin. Invest.

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The output of carbon dioxide by the lungs is primarily dependent upon the oxidative metabolism of the organism, and may, indeed, be used as a measure of oxidative processes under appropriate conditions (1 to 3). It is well recognized, however, that augmentation or depletion of the large quantity of CO2 stored within the body, which occurs during alkalosis or acidosis, may produce alterations in respiratory CO2 output, independent of oxidative metabolism (4 to 7). Some attempts have been made to establish quantitative relationships between such changes in the output of CO2 by the lungs and fluctuations of acid-base equilibrium within the organism. Shaw (8) measured the respiratory exchange of cats subjected to artificial ventilation with C02-rich mixtures, and correlated the CO2 exchange of the whole animal with variations in blood CO2 content. From such observations, the amount of CO2 absorbed by the tissues could be estimated. Irving and his coworkers (9, 10) made direct determinations of the CO2 content of various tissues of dogs and cats overventilated with air and with CO2 enriched-mixtures. They attempted to account for the net CO2 exchange of the whole organism in terms of altered CO2 content of blood, muscle, bone, and viscera. Applications of Shaw's technique in an effort to determine the CO2 capacity of the human body has been reported by Adolph, Nance, and Shiling (11). Their results were inconclusive, as were those of similar studies by Brocklehurst and Henderson (12) EXPERIMENTAL PROCEDURES AND METHODSThe experiments involving measurement of respiratory exchange were carried out on normal male adults (the same subject was used in all but 2 experiments). The fasting subject came to the laboratory at about 8 a.m. and rested for one-half hour under basal conditions. The basal respiratory exchange was determined over a 10-minute period by the open circuit method, with the subject breathing through a rubber mouthpiece into a Tissot spirometer. Analyses of the expired air for CO2 and oxygen were carried out in duplicate by means of a modified Haldane apparatus. The usual precautions were taken to avoid leaks and the apparatus was checked from time to time by analyses of atmospheric air.Venous blood samples for determination of serum CO2content were obtained anaerobically, without stasis, immediately before the initiation of the procedure designed to alter acid-base equilibrium. In the overventilation experiments, as soon as the blood was in the syringe, the subject began to breathe into the spirometer at a ventilation rate about twice normal. After 5 to 10 minutes of overbreathing, a second venepuncture was made and the spirometer disconnected as soon as the blood sample had been obtained. CALCULATIONSThe magnitude of change in respiratory C02 output produced by altered acid-base equilibrium was calculated as follows:1. The respiratory quotient of the basal period was calculated from the C02 output and oxygen consumption of that period.2. The oxygen consumed during the period of acid-base change was mult...

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Carbohydrate metabolism and muscular exercise

Cited by 12 publications

References 6 publications

The effects of alanine, glucose and starch ingestion on the ketosis produced by exercise and by starvation.

The effects of alanine, glucose and starch ingestion on the ketosis produced by exercise and by starvation.

The Effect on Respiration of Infusions of Adrenaline and Noradrenaline Into the Carotid and Vertebral Arteries in Man

The Influence of Alterations in Acid-Base Balance Upon Transfers of Carbon Dioxide and Bicarbonate in Man 1

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