Hormonal regulation of pyruvate dehydrogenase

Jungas, Robert L.

doi:10.1016/0026-0495(71)90058-8

Cited by 124 publications

(37 citation statements)

References 14 publications

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“…The activation of the enzyme results from an increase in the fraction of the enzyme present in the active unphosphorylated form Weiss et al, 1971;Taylor & Jungas, 1974). This effect of insulin can be reversed by adrenaline or ACTH$ Jungas, 1971). These hormonal influences are of special significance in the regulation oflipogenesis in rat adipose tissue, since the activity of pyruvate dehydrogenase appears to be one factor limiting the capacity of this pathway (Taylor & Jungas, 1974).…”

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confidence: 99%

“…Further, neither the pyruvate dehydrogenase kinase or the pyruvate dehydrogenase phosphate phosphatase appear to be directly affected by cyclic AMP or cyclic GMP (Jungas, 1971;Hucho et al, 1972;Siess & Wieland, 1972;Randle & Denton, 1973). As a first step in exploring the mechanisms by which insulin might influence the degree of phosphorylation of this mitochondrial protein, we have sought to determine whether it is the pyruvate dehydrogenase kinase, the pyruvate dehydrogenase phosphate phosphatase, or both whose activity is modulated by the hormone.…”

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confidence: 99%

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Activation of pyruvate dehydrogenase in adipose tissue by insulin. Evidence for an effect of insulin on pyruvate dehydrogenase phosphate phosphatase

Mukherjee

Jungas

1975

Biochemical Journal

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1. The mechanism by which insulin activates pyruvate dehydrogenase in rat epididymal adipose tissue was further investigated. 2. When crude extracts, prepared from tissue segments previously exposed to insulin (2m-i.u/ml) for 2min, were supplemented with Mg-2+, Ca-2+, glucose and hexokinase and incubated at 30 degrees C, they displayed an enhanced rate of increase in pyruvate dehydrogenase activity compared with control extracts. 3. When similar extracts were instead supplemented with fluoride, ADP, creatine phosphate and creatine kinase, the rate of decrease in pyruvate dehydrogenase activity observed during incubation at 30 degrees C was unaffected by insulin treatment. 4. It is suggested that insulin increases the fraction of pyruvate dehydrogenase present in the tissue in the active dephospho form by increasing the activity of pyruvate dehydrogenase phosphate phosphatase.

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confidence: 99%

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Activation of pyruvate dehydrogenase in adipose tissue by insulin. Evidence for an effect of insulin on pyruvate dehydrogenase phosphate phosphatase

Mukherjee

Jungas

1975

Biochemical Journal

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“…After glucose feeding the non-glucose-C was replaced by glucose-C at a 4-fold faster rate. Although similar techniques have been used in vitro to show that glucose and insulin treatment over come rate-limiting steps in the formation of 2-C units [11], such large changes have not been described before, to our knowledge, es pecially in vivo.…”

Section: Discussionmentioning

confidence: 99%

“…The extent to which an increase in the supply of 2-C units, the activation of glucose transport [22], of glycolytic enzymes [11] and of fatty acid synthesizing enzymes arc responsible for these rate changes, re quires further study using other techniques.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Lipogenic Responses to Dietary Glucose in Selected Mouse Adipose Tissues

et al. 1981

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Rates of fatty acid synthesis from glucose-carbon (glucose-C) and all other 2-carbon (2-C) units were measured in three white adipose tissue sites of fasted and fed mice, which were given a test meal containing [U-¹⁴C]glucose. Total fatty acid synthesis was measured in all mice by intraperitoneal injection of ³H₂O. In fasted-refed mice the rates of lipogenesis from glucose-C and all 2-C sources were much faster in popliteal than in epididymal fat. Most of the newly synthesized fatty acids were derived from glucose-C. However, in fed-refed mice these differences between the sites were minimal, and all the absolute rates were much higher than those found in fasted-refed mice. This suggested that the adipose tissue in the three sites did not have different physiological roles. Variability in the actual rates of lipogenesis, from one experiment to another, in fasted-refed mice could be attributed to small differences in the periods of fasting, before the mice were given the test meal.

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“…'4C02 release from [1-'4C]pyruvate has been used, e.g. in the perfused rat liver (Haussinger et al, 1975;Scholz et al, 1978;Patel et al, 1982;Zwiebel et al, 1982;Sies et al, 1983), heart (Hiltunen & Hassinen, 1976;Dennis et al, 1979;Waymack et al, 1979;Bunger et al, 1983), and skeletal muscle (Schadewaldt et al, 1983b,c) (Jungas, 1971; for further references see Denton & Hughes, 1978) and the lactating mammary gland (Kankel & Reinauer, 1976;Baxter & Coore, 1978). Contradictory results have been reported for the rat heart (Kerbey et al, 1976;Ohlen et al, 1978) and liver (Patzelt et al, 1973;Topping et al, 1977 Hennig et al (1975), and studies on the putative intracellular mediator of insulin (Jarett & Seals, 1979;Larner et al, 1979) (Hansford & Cohen, 1978;Dennis et al, 1979;Waymack et al, 1979;Bunger et al, 1983).…”

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Influence of insulin and glucose on pyruvate catabolism in perfused rat hindlimbs

Schadewaldt¹,

Lammers²,

Staib³

1985

Biochemical Journal

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The effects of insulin and glucose on the oxidative decarboxylation of pyruvate in isolated rat hindlimbs was studied in non-recirculating perfusion with [1-'4C]pyruvate. Insulin increased the calculated pyruvate decarboxylation rate in a concentration-dependent manner. At supramaximal insulin concentrations, the calculated pyruvate decarboxylation rate was increased by about 40% in perfusions with 0.15-1.5mM-pyruvate. Glucose up to 20mM had no effect. In the presence of insulin and low physiological pyruvate concentrations (0.15mM), glucose increased the calculated pyruvate oxidation. This effect was abolished by high concentrations of pyruvate (1 mM). The data provide evidence that in resting perfused rat skeletal muscle insulin primarily increased the activity of the pyruvate dehydrogenase complex. The effect of glucose was due to increased intracellular pyruvate supply.

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Hormonal regulation of pyruvate dehydrogenase

Cited by 124 publications

References 14 publications

Activation of pyruvate dehydrogenase in adipose tissue by insulin. Evidence for an effect of insulin on pyruvate dehydrogenase phosphate phosphatase

Activation of pyruvate dehydrogenase in adipose tissue by insulin. Evidence for an effect of insulin on pyruvate dehydrogenase phosphate phosphatase

Comparison of Lipogenic Responses to Dietary Glucose in Selected Mouse Adipose Tissues

Influence of insulin and glucose on pyruvate catabolism in perfused rat hindlimbs

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