scholarly journals Exercise Training Increases the Activity of Pyruvate Dehydrogenase Complex in Skeletal Muscle of Diabetic Rats.

2002 ◽  
Vol 49 (5) ◽  
pp. 547-554 ◽  
Author(s):  
NAOYA NAKAI ◽  
YUTAKA MIYAZAKI ◽  
YUZO SATO ◽  
YOSHIHARU OSHIDA ◽  
MASARU NAGASAKI ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Diabetic Rats ◽  
Dehydrogenase Complex

Insulin-induced activation of pyruvate dehydrogenase complex in skeletal muscle of diabetic rats

Metabolism ◽  
1993 ◽  
Vol 42 (5) ◽  
pp. 615-623 ◽  
Author(s):  
Pamela W. Feldhoff ◽  
Jame Arnold ◽  
Brett Oesterling ◽  
Thomas C. Vary
Keyword(s):  
Skeletal Muscle ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Diabetic Rats ◽  
Dehydrogenase Complex

scholarly journals Conversion of inactive (phosphorylated) pyruvate dehydrogenase complex into active complex by the phosphate reaction in heart mitochondria is inhibited by alloxan-diabetes or starvation in the rat

1978 ◽  
Vol 173 (2) ◽  
pp. 669-680 ◽  
Author(s):  
N J Hutson ◽  
A L Kerbey ◽  
P J Randle ◽  
P H Sugden
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Rat Heart ◽  
Pyruvate Dehydrogenase Complex ◽  
Diabetic Rats ◽  
Atp Depletion ◽  
Heart Mitochondria ◽  
Active Complex ◽  
Phosphate Complex ◽  
Rat Hearts ◽  
Dehydrogenase Complex

1. The conversion of inactive (phosphorylated) pyruvate dehydrogenase complex into active (dephosphorylated) complex by pyruvate dehydrogenase phosphate phosphatase is inhibited in heart mitochondria prepared from alloxan-diabetic or 48h-starved rats, in mitochondria prepared from acetate-perfused rat hearts and in mitochondria prepared from normal rat hearts incubated with respiratory substrates for 6 min (as compared with 1 min). 2. This conclusion is based on experiments with isolated intact mitochondria in which the pyruvate dehydrogenase kinase reaction was inhibited by pyruvate or ATP depletion (by using oligomycin and carbonyl cyanide m-chlorophenylhydrazone), and in experiments in which the rate of conversion of inactive complex into active complex by the phosphatase was measured in extracts of mitochondria. The inhibition of the phosphatase reaction was seen with constant concentrations of Ca2+ and Mg2+ (activators of the phosphatase). The phosphatase reaction in these mitochondrial extracts was not inhibited when an excess of exogenous pig heart pyruvate dehydrogenase phosphate was used as substrate. It is concluded that this inhibition is due to some factor(s) associated with the substrate (pyruvate dehydrogenase phosphate complex) and not to inhibition of the phosphatase as such. 3. This conclusion was verified by isolating pyruvate dehydrogenase phosphate complex, free of phosphatase, from hearts of control and diabetic rats an from heart mitochondria incubed for 1min (control) or 6min with respiratory substrates. The rates of re-activation of the inactive complexes were then measured with preparations of ox heart or rat heart phosphatase. The rates were lower (relative to controls) with inactive complex from hearts of diabetic rats or from heart mitochondria incubated for 6min with respiratory substrates. 4. The incorporation of 32Pi into inactive complex took 6min to complete in rat heart mitocondria. The extent of incorporation was consistent with three or four sites of phosphorylation in rat heart pyruvate dehydrogenase complex. 5. It is suggested that phosphorylation of sites additional to an inactivating site may inhibit the conversion of inactive complex into active complex by the phosphatase in heart mitochondria from alloxan-diabetic or 48h-starved rats or in mitochondria incubated for 6min with respiratory substrates.

Insulin activation of pyruvate dehydrogenase complex is enhanced by exercise training

Metabolism ◽  
1999 ◽  
Vol 48 (7) ◽  
pp. 865-869 ◽  
Author(s):  
Naoya Nakai ◽  
Yuzo Sato ◽  
Yoshiharu Oshida ◽  
Noriaki Fujitsuka ◽  
Atsushi Yoshimura ◽  
...  
Keyword(s):  
Exercise Training ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Dehydrogenase Complex

scholarly journals Tissue-specific pyruvate dehydrogenase complex deficiency causes cardiac hypertrophy and sudden death of weaned male mice

2008 ◽  
Vol 295 (3) ◽  
pp. H946-H952 ◽  
Author(s):  
Sukhdeep Sidhu ◽  
Ashish Gangasani ◽  
Lioubov G. Korotchkina ◽  
Gen Suzuki ◽  
James A. Fallavollita ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mouse Model ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Left Ventricular ◽  
Oxidative Decarboxylation ◽  
Male Mice ◽  
Wild Type ◽  
Α Subunit ◽  
Dehydrogenase Complex

Pyruvate dehydrogenase complex (PDC) plays an important role in energy homeostasis in the heart by catalyzing the oxidative decarboxylation of pyruvate derived primarily from glucose and lactate. Because various pathophysiological states can markedly alter cardiac glucose metabolism and PDC has been shown to be altered in response to chronic ischemia, cardiac physiology of a mouse model with knockout of the α-subunit of the pyruvate dehydrogenase component of PDC in heart/skeletal muscle (H/SM-PDCKO) was investigated. H/SM-PDCKO mice did not show embryonic lethality and grew normally during the preweaning period. Heart and skeletal muscle of homozygous male mice had very low PDC activity (∼5% of wild-type), and PDC activity in these tissues from heterozygous females was ∼50%. Male mice did not survive for >7 days after weaning on a rodent chow diet. However, they survived on a high-fat diet and developed left ventricular hypertrophy and reduced left ventricular systolic function compared with wild-type male mice. The changes in the heterozygote female mice were of lesser severity. The deficiency of PDC in H/SM-PDCKO male mice greatly compromises the ability of the heart to oxidize glucose for the generation of energy (and hence cardiac function) and results in cardiac pathological changes. This mouse model demonstrates the importance of glucose oxidation in cardiac energetics and function under basal conditions.

Effect of sepsis on activity of pyruvate dehydrogenase complex in skeletal muscle and liver

1986 ◽  
Vol 250 (6) ◽  
pp. E634-E640 ◽  
Author(s):  
T. C. Vary ◽  
J. H. Siegel ◽  
T. Nakatani ◽  
T. Sato ◽  
H. Aoyama
Keyword(s):  
Skeletal Muscle ◽  
Pyruvate Dehydrogenase ◽  
Concentration Ratio ◽  
Coenzyme A ◽  
Pyruvate Dehydrogenase Complex ◽  
Sterile Inflammation ◽  
Active Complex ◽  
Small Abscess ◽  
Dehydrogenase Complex ◽  
Large Abscess

The effect of chronic sepsis on the concentration of active pyruvate dehydrogenase complex has been investigated in liver and skeletal muscle of normal, sterile inflammatory, and chronic septic (small and large abscess) animals. Hyperdynamic sepsis was induced by the intraperitoneal introduction of a rat fecal-agar pellet of known size and bacterial composition (Escherichia coli + Bacteroides fragilis). Total pyruvate dehydrogenase complex activity was not altered in either liver or skeletal muscle in any of the conditions studied. In hepatic tissue, sterile inflammation increased the proportion of active complex 2.5-fold compared with control. The same increase in the concentration of active complex was observed in animals with a small abscess. When the abscess size was increased (large abscess), the concentration of active complex was decreased relative to sterile inflammatory or small abscess septic animals. In contrast to liver, sterile inflammation did not alter the proportion of active complex in skeletal muscle. Sepsis (either small or large septic abscess) resulted in threefold decrease in the concentration of active complex relative to control or sterile inflammatory animals. Changes in the concentration of active complex did not appear to be dependent on the ATP/ADP concentration ratio or tissue pyruvate levels but were consistent with changes in the acetyl-coenzyme A-to-coenzyme A concentration ratio. The mechanism responsible for altered concentration of active complex may be mediated through changes in the activity of the pyruvate dehydrogenase kinase, secondary to alterations in the effector concentration ratios.

Sign in / Sign up

Export Citation Format

Share Document