Carbohydrate metabolism in contracting dog skeletal muscle in situ

Chapler, CK; Stainsby, WN

doi:10.1152/ajplegacy.1968.215.5.995

Cited by 42 publications

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“…During the 3 h studied in the present investigation the increase in glycogen synthesis after contraction was not large enough to restore glycogen to the level observed before contraction. Similar results have been reported for the in situ preparation of the gastrocnemius-plantaris muscle group of the dog, stimulated 5 time+ for 60 min (Chapler and Stainsby 1968). In that preparation complete recovery of the glycogen was not obtained within the 2 h studied.…”

Section: Discussionsupporting

confidence: 89%

Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle

Adolfsson

1973

Acta Physiologica Scandinavica

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The influence of contraction on the content of glycogen in muscle as well as on the activity of the glycogen synthetase enzyme (EC 2.4. 1. 11.)—rate‐limiting for glycogen synthesis—has previously been investigated in vivo. In the present study this influence was studied in vitro, where interference of epinephrine and insulin on the the effects of contraction is more easily excluded. Electrically stimulated intact levator ani muscle preparations from prepubertal rats were used (Arvill, Acta endocr. 1967. 56. suppl. 122). Glycogen content decreased during 15 min of intermittent tetanization (10 slmin). There was no change in synthetase activity during the contractions. For the period following contractions an increase in the per cent active I‐form of the enzyme was found after 1, 2, 10 and 180 min. Resynthesis of glycogen was shown after 30–180 min. An inverse relation between % I‐form and glycogen content was found when data from 1–10 min after contractions were plotted together with the data from unstirnulated muscles. During repeated single twitches (1/s) for 60 min there was an enhanced penetration of xylose‐14C and a higher rate of incorporation of glucose‐14C into glycogen compared to control muscles. The present results are in good agreement with those previously obtained in vivo. Thus, the influence of contractions in vivo could be demonstrated also in vitro.

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Section: Discussionsupporting

confidence: 89%

Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle

Adolfsson

1973

Acta Physiologica Scandinavica

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“…The reasons why these studies in contrast to the present study did not convincingly reveal the significance of an intact sympathoadrenal system for the glycogen depletion during exercise are likely to be found in the use of less efficient sympathectomy procedures (Gollnick et al 1970, Maling et al 1966 (Gollnick et al 1970, Sembrowich et al 1974 or in the employed exercise procedures. It has been repeatedly observed that glycogen depletion can be elicited in isolated, perfused skeletal muscle by electrical stimulation (Berger et al 1975, Chapler and Stainsby 1968, Costin et al 1970, Helmreich and Cori 1966, Karlsson, Rosell and Saltin 1972. Furthermore, the capacity for work performance is reduced in patients with McArdle's disease, in whom muscular glycogenolysis is inhibited by a deficiency of glycogen phosphorylase (Pearson, Rimer and Mommaerts 1961).…”

Section: Discussionmentioning

confidence: 99%

Sympathetic control of metabolic and hormonal responses to exercise in rats

Galbo

Richter

Christensen

et al. 1978

Acta Physiologica Scandinavica

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The importance of the sympatho-adrenal system for the pancreatic hormonal response to exercise and, furthermore, the role of glucagon and catecholamines for the hepatic glycogen depletion during exercise were studied. Rats were either surgically adrenomedullectomized and chemically sympathectomized with 6-hydroxydopamine or shamtreated. Two weeks later the rats had either rabbit-antiglucagon serum or normal rabbit serum injected. Subsequently the rats either rested or swam with a tail weight for 75 min. Immediately afterwards cardiac blood was drawn and liver and muscle tissue collected. In control rats in spite of an increase in blood glucose concentrati4ns during exercise plasma insulin concentrations were unchanged, while glucagon concentrations increased. In sympathectomized rats, compared to control rats, glucagon concentrations increased less, and insulin concentrations were higher, although glucose concentrations were lower during exercise. Sympathectomy completely abolished the exercise-induced decrease in liver and muscle glycogen concentrations, whereas neither glycogen depletion nor plasma catecholamine concentrations were influenced by the administration of glucagon antibodies. These findings indicate that the sympatho-adrenal system enhances glucagon secretion as well as muscular and hepatic glycogen depletion but inhibits insulin secretion in exercising rats. The increase in glucagon concentrations, however, does not enhance hepatic glycogen depletion at the work load used.

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“…These values are somewhat higher than those of Zierler et al [41], who estimated that the oxidation cf glucose by the forearm muscle of man accounts for about \Q% of the total oxygen consumption. Other groups have reported values ranging from 0 to 60 for the percentage of oxygen consumption accounted for by glucose oxidation in skeletal muscle [12]. The relative amounts of carbohydrate versus lipid utilized by adult cardiac muscle range widely and are influenced by the hormonal and physiologic condition of the animal [10,27,34,39]; the same is probably true of voluntary skeletal muscle but less data are available on this tissue [12].…”

Section: Discussionmentioning

confidence: 99%

Glucose Utilization of Cardiac and Skeletal Muscle Homogenates from Fetal and Adult Rhesus Monkesy

et al. 1972

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ExtractThe oxygen consumptions and CO 2 productions were similar for the homogenates of adult and 113-day fetal muscle from rhesus monkeys but higher in the 155-day fetal series (Table I). The percentages of total CO 2 and the micromoles of CO 2 arising from glucose plus glycogen (carbohydrate) were the same in homogenates of fetal and adult skeletal muscle. No difference was observed between the metabolism of homogenates of adult and neonatal muscle.In homogenates of cardiac muscle, the oxygen consumption and CO 2 production in fetal muscle were higher at 113 days than in adult muscle; by 155 days, values in the fetal and adult muscle were similar ( Table I). The percentage of total CO 2 arising from carbohydrate and the micromoles of CO 2 produced from the oxidation of carbohydrate were higher in both fetal series than in the adult. The oxygen consumption, CO 2 production, and micromoles of CO 2 arising from carbohydrate per gram protein per 30 min were two-to sevenfold higher in cardiac than in skeletal muscle, the greatest difference occurring in the 113-day fetal series. However, the percentages of total CO 2 arising from carbohydrate were remarkably similar; the only difference was seen in the adult series where skeletal muscle was relatively more dependent on carbohydrate as a substrate than cardiac muscle. All these parameters were also measured in homogenates of cardiac muscle from neonates, and no difference in metablism was observed between the neonatal and adult series.In the fetal homogenates from both types of muscle, a major portion, 65 to 73%, of the total CO 2 produced originated from a source or sources other than glucose and glycogen. Thus, both skeletal and cardiac homogenates of fetal, neonatal, and adult muscle are potentially able to obtain a large portion of their energy from the oxidation of substrates other than glucose and glycogen. SpeculationIn vitro experiments from our laboratory demonstrate that 65% or more of the total CO 2 produced by skeletal and cardiac muscle homogenates originated from the oxidation of substrates other than glucose and glycogen in the fetal as well as in the adult series; the data from broken cell preparations (homogenate) and previous data from intact cell preparations (muscle fiber groups) are similar. The possibility that other tissues and organs of the fetus utilize noncarbohydrates as an energy 813 814 BEATTY, YOUNG, DWYER, AND BOCEK source should be investigated. Tsoulos et al. have reported that fetal lambs obtain a maximum of 50% of their metabolic requirements from glucose utilization under presumably normal conditions.

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Carbohydrate metabolism in contracting dog skeletal muscle in situ

Cited by 42 publications

References 0 publications

Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle

Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle

Sympathetic control of metabolic and hormonal responses to exercise in rats

Glucose Utilization of Cardiac and Skeletal Muscle Homogenates from Fetal and Adult Rhesus Monkesy

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