Enzyme activities of glycogen metabolism and mitochondrial characteristics in muscles of RN− carrier pigs (Sus scrofa domesticus)

Estrade, Marielle; Ayoub, Samir S.; Talmant, André; Monin, Gabriel

doi:10.1016/0305-0491(94)90080-9

Cited by 39 publications

(32 citation statements)

References 18 publications

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“…In porcine FG semimembranosus and longissimus dorsi muscles, the activity of PHOS correlated negatively with GP, different to the report of Estrade, Ayoub, Talmant & Monin (1994) for porcine longissimus dorsi muscle. Furthermore, the activity of PHOS correlated positively with the ultimate pH in FG porcine muscles.…”

Section: Porcine and Bovine Fast Twitch And Glycolytic Versus Slow Twcontrasting

confidence: 99%

“…Dalrymple, Kastenschmidt & Cassens, 1973;Estrade, Ayoub, Talmant & Monin, 1994;Fernandez, Neyraud, Astruc & Sante, 2002;Monin, MejenesQuijano, Talmant & Sellier, 1987;Schwägele, Lopez Buesa & Honikel, 1996;Suuronen, 1995) and also in cattle (Talmant, Monin, Briand, Dadet & Briand, 1986). However, less attention has been paid to GDE despite suggestions of its role in slowing down the rate of post-mortem glycogenolysis and thus glycolysis, particularly when the glycogen limit dextrin state is concerned (Kylä-Puhju et al, 2005;Taylor et al, 1975).…”

Section: Introductionmentioning

confidence: 99%

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The significance of the activity of glycogen debranching enzyme in glycolysis in porcine and bovine muscles

2006

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The purpose of the study was to examine the activity of glycogen debranching enzyme, GDE, in porcine and bovine muscles differing in rate of contraction and in oxidative capacity. The activity of GDE, the activity of phosphorylase, total glucose content, lactate content and pH were measured from meat samples taken 35 min post-mortem and ultimate pH 24 or 48 h post-mortem.Both GDE and phosphorylase are needed for the complete degradation of glycogen. In porcine muscles the activities of these glycogen degrading enzymes were higher than in bovine muscles. The activities were increasing with the increasing fast twitch and glycolytic character of a muscle of a given species. However, the increase in the activity of phosphorylase was greater than the increase in the activity of GDE. It was concluded that the GDE may restrict the rate of glycolysis in fast twitch muscles.

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Section: Porcine and Bovine Fast Twitch And Glycolytic Versus Slow Twcontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The significance of the activity of glycogen debranching enzyme in glycolysis in porcine and bovine muscles

2006

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“…The γ subunit includes γ1, γ2 and γ3 isoforms, with γ3 being the predominant isoform in glycolytic skeletal muscle [21], a fibre type that depends upon the anaerobic metabolism of glucose when there is a high demand for energy. In skeletal muscle from pigs carrying a naturally occurring mutation of γ3 (R225Q), glycogen content [22,23] and the activities of citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase are increased [24,25], suggesting that the γ3 subunit can regulate metabolic properties of skeletal muscle.…”

Section: Introductionmentioning

confidence: 99%

Role of AMP-activated protein kinase in the coordinated expression of genes controlling glucose and lipid metabolism in mouse white skeletal muscle

Long

Barnes

Mahlapuu³

et al. 2005

Diabetologia

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Aims/hypothesis: AMP-activated protein kinase (AMPK) regulates metabolic adaptations in skeletal muscle. The aim of this study was to investigate whether AMPK modulates the expression of skeletal muscle genes that have been implicated in lipid and glucose metabolism under fed or fasting conditions. Methods: Two genetically modified animal models were used: AMPK γ3 subunit knockout mice (Prkag3 −/− ) and skeletal musclespecific transgenic mice (Tg-Prkag3225Q ) that express a mutant (R225Q) γ3 subunit. Levels of mRNA transcripts of genes involved in lipid and glucose metabolism in white gastrocnemius muscles of these mice (under fed or 16-h fasting conditions) were assessed by quantitative real-time PCR. Results: Wild-type mice displayed a coordinated increase in the transcription of skeletal muscle genes encoding proteins involved in lipid/oxidative metabolism (lipoprotein lipase, fatty acid transporter, carnitine palmitoyl transferase-1 and citrate synthase) and glucose metabolism (glycogen synthase and lactate dehydrogenase) in response to fasting. In contrast, these fasting-induced responses were impaired in Prkag3 −/− mice. The transcription of genes involved in lipid and oxidative metabolism was increased in the skeletal muscle of Tg-Prkag3 225Q mice compared with that in wild-type mice. Moreover, the expression of the genes encoding hexokinase II and 6-phosphofrucktokinase was decreased in Tg-Prkag3 225Q mice after fasting. Conclusions/ interpretation: AMPK is involved in the coordinated transcription of genes critical for lipid and glucose metabolism in white glycolytic skeletal muscle.

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“…Naturally occurring mutations in ␥2 and ␥3 are now well recognized, the former contributing to the arrhythmias and cardiomyopathy of the Wolff-Parkinson-White syndrome (2). The Hampshire pig (Sus scrofa domesticus; RN Ϫ ) is an interesting model of the impact of a ␥3 subunit mutation (R200Q) in skeletal muscle, leading to marked glycogen accumulation (11,12,29). This phenotype has been replicated in a murine model with an identically placed mutation in the mouse ␥3 subunit (R225Q) (3)(4)(5)38).…”

mentioning

confidence: 99%

Genetic model for the chronic activation of skeletal muscle AMP-activated protein kinase leads to glycogen accumulation

Barre

Richardson²,

Hirshman³

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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is an important metabolic sensor/effector that coordinates many of the changes in mammalian tissues during variations in energy availability. We have sought to create an in vivo genetic model of chronic AMPK activation, selecting murine skeletal muscle as a representative tissue where AMPK plays important roles. Muscleselective expression of a mutant noncatalytic ␥1 subunit (R70Q␥) of AMPK activates AMPK and increases muscle glycogen content. The increase in glycogen content requires the presence of the endogenous AMPK catalytic ␣-subunit, since the offspring of cross-breeding of these mice with mice expressing a dominant negative AMPK␣ subunit have normal glycogen content. In R70Q␥1-expressing mice, there is a small, but significant, increase in muscle glycogen synthase (GSY) activity associated with an increase in the muscle expression of the liver isoform GSY2. The increase in glycogen content is accompanied, as might be expected, by an increase in exercise capacity. Transgene expression of this mutant AMPK␥1 subunit may provide a useful model for the chronic activation of AMPK in other tissues to clarify its multiple roles in the regulation of metabolism and other physiological processes. glycogen synthase; exercise; transgenic mice THE AMP-ACTIVATED PROTEIN KINASE (AMPK) is an important sensor/effector that coordinates many of the changes in mammalian tissues during variations in energy availability (24,26,27). Upon allosteric stimulation by AMP and activation by AMPKKs, AMPK acts to phosphorylate several proteins that increase the rates of glucose and fatty acid metabolism to correct the deficit in ATP that occurs during metabolic stresses. AMPK is a heterotrimeric protein, consisting of an ␣-catalytic subunit, a ␤-subunit important both for enzyme activity and targeting, and a ␥-subunit, which binds the activating AMP. Activity requires phosphorylation of the ␣-subunit on Thr 172 by one or more AMPKKs (24,26,27,33).To exploit the possibility that a mutation in a ␥-subunit might create a model of chronic AMPK activation and, reasoning that the ␥1 subunit was the most widely expressed ␥-subunit, we previously examined the impact of a mutation in the ␥1 subunit (R70Q␥1) on AMPK activity in cell-based systems (18). Three AMPK ␥-subunits (␥1, ␥2, ␥3), are coded by three separate genes, ␥1 being the most ubiquitously expressed, whereas ␥2 and ␥3 have more restricted expression (8,24,26,27). The ␥-subunits bind AMP, activating the heterotrimer; however, mutations in the AMP binding pocket of ␥1 can create an activated heterotrimer that is relatively independent of allosteric regulation by AMP (1, 18). Naturally occurring mutations in ␥2 and ␥3 are now well recognized, the former contributing to the arrhythmias and cardiomyopathy of the Wolff-Parkinson-White syndrome (2). The Hampshire pig (Sus scrofa domesticus; RN Ϫ ) is an interesting model of the impact of a ␥3 subunit mutation (R200Q) in skeletal muscle, leading to marked glycogen accumulation (11,12,29). This phenotype has been replicated in a murine model ...

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Enzyme activities of glycogen metabolism and mitochondrial characteristics in muscles of RN− carrier pigs (Sus scrofa domesticus)

Cited by 39 publications

References 18 publications

The significance of the activity of glycogen debranching enzyme in glycolysis in porcine and bovine muscles

The significance of the activity of glycogen debranching enzyme in glycolysis in porcine and bovine muscles

Role of AMP-activated protein kinase in the coordinated expression of genes controlling glucose and lipid metabolism in mouse white skeletal muscle

Genetic model for the chronic activation of skeletal muscle AMP-activated protein kinase leads to glycogen accumulation

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