14 results on '"Ventura-Clapier R"'
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2. Potentiating exercise training with resveratrol
- Author
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Ventura-Clapier, R.
- Published
- 2012
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3. Depressed mitochondrial transcription factors and oxidative capacity in rat failing cardiac and skeletal muscles.
- Author
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Garnier, A., Fortin, D., Deloménie, C., Momken, I., Veksler, V., and Ventura-Clapier, R.
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- 2003
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- View/download PDF
4. Physical activity changes the regulation of mitochondrial respiration in human skeletal muscle.
- Author
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Zoll, J., Sanchez, H., N'Guessan, B., Ribera, F., Lampert, E., Bigard, X., Serrurier, B., Fortin, D., Geny, B., Veksler, V., Ventura-Clapier, R., and Mettauer, B.
- Published
- 2002
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5. Compartmentation of creatine kinase isoenzymes in myometrium of gravid guinea‐pig.
- Author
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Clark, J F, Khuchua, Z, Kuznetsov, A, Saks, V A, and Ventura‐Clapier, R
- Abstract
1. This study was performed to investigate the possible presence and role of the creatine kinase (CK) system in the contraction and relaxation of skinned guinea‐pig uterus as well as the changes of the CK system during gestation. Experiments were performed on isolated longitudinal fibres of gravid and non‐gravid myometrium. 2. Total CK activity increased from 74 +/‐ 11 to 196 +/‐ 39 IU (g wet wt)‐1 during gestation. 3. The four isoenzymes of CK: muscle (MM), muscle‐brain (MB), brain (BB) and mitochondrial (mt‐CK) were found in myometrium. MM, MB and BB isoenzymes represented respectively 20.3 +/‐ 2.6, 10.3 +/‐ 4.4 and 72.7 +/‐ 2.2% of total activity. The distribution of isoenzymes did not significantly change with gestation, the contribution of mt‐CK increasing from trace to 5% of total activity. 4. BB‐CK was specifically bound to Triton X‐100‐skinned fibres with the non‐gravid uterus containing 6.7 +/‐ 1.9 IU (g wet wt)‐1 and the gravid uterus containing 44 +/‐ 13 IU (g wet wt)‐1. 5. Active tension of Triton X‐100‐treated fibres increased from 6.06 +/‐ 0.68 to 19.3 +/‐ 1.9 mM mm‐2 during gestation. 6. Submaximal tension (43.3 +/‐ 4.4% of maximal tension) can be developed in the absence of ATP and in the presence of 12 mM phosphocreatine (PCr) and 250 microM MgADP from endogenous CK in non‐gravid uterine fibres while the gravid uterus was able to generate 65.4 +/‐ 3.9% of maximal tension via the CK system. 7. The endogenous CK system was able to relax the skinned fibres from high‐tension rigor conditions by 47.3 +/‐ 4.2% of total relaxation in non‐gravid fibres and 60.6 +/‐ 3.2% of total relaxation in gravid fibres. 8. Non‐gravid and gravid uteri both contained mt‐CK of 17.5 +/‐ 8.4 and 140 +/‐ 22 micrograms (g wet wt)‐1 respectively as determined with antibodies against mt‐CK. 9. Oxygen consumption was studied in fibres where the plasmalemma was solubilized with 50 micrograms ml‐1 saponin. Maximal respiration was increased from 0.91 +/‐ 0.05 to 2.61 +/‐ 0.16 mumol oxygen min‐1 (g dry wt)‐1 in the gravid uterine fibres. However, creatine did not stimulate respiration in the uterine fibres treated with saponin. 10. It is concluded that the CK system undergoes qualitative as well as quantitative changes during gestation. BB‐CK is specifically localized in the myofilaments and mt‐CK is present in the uterine mitochondria.(ABSTRACT TRUNCATED AT 400 WORDS)
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- 1993
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6. Errata.
- Author
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Garnier, A., Fortin, D., Deloménie, C., Momken, I., Veksler, V., and Ventura‐Clapier, R.
- Published
- 2003
- Full Text
- View/download PDF
7. Postnatal development of mouse heart: formation of energetic microdomains.
- Author
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Piquereau J, Novotova M, Fortin D, Garnier A, Ventura-Clapier R, Veksler V, and Joubert F
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- Adenine Nucleotides metabolism, Animals, Animals, Newborn, Blotting, Western, Calcium metabolism, Cardiomegaly metabolism, Cardiomegaly pathology, Mice, Mice, Inbred C57BL, Microscopy, Electron, Mitochondria, Heart metabolism, Mitochondria, Heart physiology, Myocardium ultrastructure, Myocytes, Cardiac physiology, Myocytes, Cardiac ultrastructure, Myofibrils metabolism, Myosins metabolism, Reverse Transcriptase Polymerase Chain Reaction, Sarcoplasmic Reticulum metabolism, Sarcoplasmic Reticulum physiology, Sarcoplasmic Reticulum ultrastructure, Sarcoplasmic Reticulum Calcium-Transporting ATPases metabolism, Energy Metabolism physiology, Heart growth & development, Heart physiology, Myocardium metabolism
- Abstract
Cardiomyocyte contractile function requires tight control of the ATP/ADP ratio in the vicinity of the myosin-ATPase and sarcoplasmic reticulum ATPase (SERCA). In these cells, the main systems that provide energy are creatine kinase (CK), which catalyses phosphotransfer from phosphocreatine to ADP, and direct adenine nucleotide channelling (DANC) from mitochondria to ATPases. However, it is not known how and when these complex energetic systems are established during postnatal development. We therefore studied the maturation of the efficacy with which DANC and CK maintain ATP/ADP-dependent SR and myofibrillar function (SR Ca(2+) pumping and prevention of rigor tension), as well as the maturation of mitochondrial oxidative capacity. Experiments were performed on saponin-skinned fibres from left ventricles of 3-, 7-, 21-, 42- and 63-day-old mice. Cardiomyocyte and mitochondrial network morphology were characterized using electron microscopy. Our results show an early building-up of energetic microdomains in the developing mouse heart. CK efficacy for myosin-ATPase regulation was already maximal 3 days after birth, while for SERCA regulation it progressively increased until 21 days after birth. Seven days after birth, DANC for these two ATPases was as effective as in adult mice, despite a non-maximal mitochondrial respiration capacity. However, 3 days after birth, DANC between mitochondria and myosin-ATPase was not yet fully efficient. To prevent rigor tension in the presence of working mitochondria, the myosin-ATPase needed more intracellular MgATP in 3-day-old mice than in 7-day-old mice (pMgATP(50) 4.03 +/- 0.02 and 4.36 +/- 0.07, respectively, P < 0.05), whereas the intrinsic sensitivity of myofibrils to ATP (when mitochondria were inhibited) was similar at both ages. This may be due to the significant remodelling of the cytoarchitecture that occurs between these ages (cytosolic space reduction, formation of the mitochondrial network around the myofibrils). These results reveal a link between the maturation of intracellular energy pathways and cell architecture.
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- 2010
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8. Local energetic regulation of sarcoplasmic and myosin ATPase is differently impaired in rats with heart failure.
- Author
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Joubert F, Wilding JR, Fortin D, Domergue-Dupont V, Novotova M, Ventura-Clapier R, and Veksler V
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- Animals, Calcium metabolism, Male, Myocardium ultrastructure, Myocytes, Cardiac metabolism, Myocytes, Cardiac ultrastructure, Myofibrils physiology, Rats, Saponins, Energy Metabolism physiology, Heart Failure metabolism, Myosins metabolism, Sarcoplasmic Reticulum Calcium-Transporting ATPases metabolism
- Abstract
Local control of ATP/ADP ratio is essential for efficient functioning of cellular ATPases. Since creatine kinase (CK) activity and mitochondrial content are reduced in heart failure (HF), and cardiomyocyte ultrastructure is altered, we hypothesized that these changes may affect the local energetic control of two major cardiac ATPases, the sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) and the myosin ATPase. Heart failure was induced by aortic stenosis in rats. Electron microscopy confirmed that failing cardiomyocytes had intracellular disorganization, with fewer contacts between mitochondria and myofibrils. Despite normal SERCA protein content, spontaneous Ca2+ release measurements using Fluo-4 on saponin-permeabilized cardiomyocytes showed a lower SR loading in HF even when endogenous CK and mitochondria were fully activated. Similarly, in permeabilized fibres, SR Ca2+ loading supported by SR-bound CK and mitochondria was significantly reduced in HF (by 49% and 40%, respectively, 43% when both systems were activated, P < 0.05). Alkaline phosphatase treatment had no effect, but glycolytic substrates normalized calcium loading in HF to the sham level. The control by CK and mitochondria of the local ATP/ADP ratio close to the myosin ATPase (estimated by rigor tension) was also significantly impaired in HF fibres (by 32% and 46%, respectively). However, while the contributions of mitochondria and CK to local ATP regeneration were equally depressed in HF for the control of SERCA, mitochondrial contribution was more severely impaired than CK (P < 0.05) with respect to myofilament regulation. These data show that local energetic regulation of essential ATPases is severely impaired in heart failure, and undergoes a complex remodelling as a result of a decreased activity of the ATP-generating systems and cytoarchitecture disorganization.
- Published
- 2008
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9. Activation of AMP kinase alpha1 subunit induces aortic vasorelaxation in mice.
- Author
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Goirand F, Solar M, Athea Y, Viollet B, Mateo P, Fortin D, Leclerc J, Hoerter J, Ventura-Clapier R, and Garnier A
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- AMP-Activated Protein Kinases, Aminoimidazole Carboxamide analogs & derivatives, Aminoimidazole Carboxamide pharmacology, Animals, Aorta, Thoracic drug effects, Dose-Response Relationship, Drug, Enzyme Activation, Enzyme Activators pharmacology, In Vitro Techniques, Isoenzymes metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Multienzyme Complexes deficiency, Multienzyme Complexes genetics, Muscle, Smooth, Vascular enzymology, Phosphorylation, Protein Serine-Threonine Kinases deficiency, Protein Serine-Threonine Kinases genetics, Ribonucleotides pharmacology, Aorta, Thoracic enzymology, Multienzyme Complexes metabolism, Protein Serine-Threonine Kinases metabolism, Vasodilation drug effects
- Abstract
Vasodilatation is a vital mechanism of systemic blood flow regulation that occurs during periods of increased energy demand. The AMP-dependent protein kinase (AMPK) is a serine/threonine kinase that is activated by conditions that increase the AMP-to-ATP ratio, such as exercise and metabolic stress. We hypothesized that AMPK could trigger vasodilatation and participate in blood flow regulation. Rings of thoracic aorta were isolated from C57Bl6 mice and mice deficient in the AMPK catalytic alpha1 (AMPKalpha1-/-) or alpha2 (AMPKalpha2-/-) subunit and their littermate controls, and mounted in an organ bath. Aortas were preconstricted with phenylephrine (1 microM) and activation of AMPK was induced by addition of increasing concentrations of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR). AICAR (0.1-3 mM) dose-dependently induced relaxation of precontracted C57BL6, AMPKalpha1+/+ and alpha2+/+ aorta (P<0.001, n=5-7 per group). This AICAR induced vasorelaxation was not inhibited by the addition of adenosine receptor antagonists. Moreover, when aortic rings were freed of endothelium by gentle rubbing, AICAR still induced aortic ring relaxation, suggesting a direct effect of AICAR on smooth muscle cells. When aortic rings were pretreated with L-NMMA (30 microM) to inhibit nitric oxide synthase activity, AICAR still induced relaxation. Western blot analysis of C57Bl6 mice denuded aorta showed that AMPK was phosphorylated after incubation with AICAR and that AMPKalpha1 was the main catalytic subunit expressed. Finally, AICAR-induced relaxation of aortic rings was completely abolished in AMPKalpha1-/- but not AMPKalpha2-/- mice. Taken together, the results show that activation of AMPKalpha1 but not AMPKalpha2 is able to induce aortic relaxation in mice, in an endothelium- and eNOS-independent manner.
- Published
- 2007
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10. Altered energy transfer from mitochondria to sarcoplasmic reticulum after cytoarchitectural perturbations in mice hearts.
- Author
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Wilding JR, Joubert F, de Araujo C, Fortin D, Novotova M, Veksler V, and Ventura-Clapier R
- Subjects
- Adenosine Diphosphate metabolism, Animals, Calcium metabolism, Creatine Kinase, MB Form metabolism, Desmin genetics, Energy Metabolism, Heart physiopathology, Kinetics, LIM Domain Proteins, Mice, Mice, Inbred C57BL, Mice, Knockout, Models, Animal, Muscle Proteins genetics, Myocardial Contraction, Myocardium pathology, Myocardium ultrastructure, Myofibrils pathology, Myofibrils ultrastructure, Energy Transfer, Mitochondria, Heart enzymology, Myocardium enzymology, Sarcoplasmic Reticulum enzymology
- Abstract
Sarcoplasmic reticulum (SR) calcium pump function requires a high local ATP/ADP ratio, which can be maintained by direct nucleotide channelling from mitochondria, and by SR-bound creatine kinase (CK)-catalysed phosphate-transfer from phosphocreatine. We hypothesized that SR calcium uptake supported by mitochondrial direct nucleotide channelling, but not bound CK, depends on the juxtaposition of these organelles. To test this, we studied a well-described model of cytoarchitectural disorganization, the muscle LIM protein (MLP)-null mouse heart. Subcellular organization was characterized using electron microscopy, and mitochondrial, SR and myofibrillar function were assessed in saponin-permeabilized fibres by measuring respiration rates and caffeine-induced tension transients. MLP-null hearts had fewer, less-tightly packed intermyofibrillar mitochondria, and more subsarcolemmal mitochondria. The apparent mitochondrial Km for ADP was significantly lower in the MLP-null heart than in control (175 +/- 15 and 270 +/- 33 microM, respectively), indicating greater ADP accessibility, although maximal respiration rate, mitochondrial content and total CK activity were unaltered. Active tension in the myofibres of MLP-null mice was 54% lower than in controls (39 +/- 3 and 18 +/- 1 mN mm(-2), respectively), consistent with cytoarchitectural disorganization. SR calcium loading in the myofibres of MLP-null mice was similar to that in control myofibres when energy support was provided via Bound CK, but approximately 36% lower than controls when energy support was provided by mitochondrial (P < 0.05). Mitochondrial support for SR calcium uptake was also specifically decreased in the desmin-null heart, which is another model of cytoarchitectural perturbation. Thus, despite normal oxidative capacity, direct nucleotide channelling to the SR was impaired in MLP deficiency, concomitant with looser mitochondrial packing and increased nucleotide accessibility to this organelle. Changes in cytoarchitecture may therefore impair subcellular energy transfer and contribute to energetic and contractile dysfunction.
- Published
- 2006
- Full Text
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11. Impaired voluntary running capacity of creatine kinase-deficient mice.
- Author
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Momken I, Lechêne P, Koulmann N, Fortin D, Mateo P, Doan BT, Hoerter J, Bigard X, Veksler V, and Ventura-Clapier R
- Subjects
- Animals, Body Weight, Creatine Kinase deficiency, Creatine Kinase, MM Form, Creatine Kinase, Mitochondrial Form, Gene Expression, Isoenzymes deficiency, Isoenzymes genetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Muscle Contraction, Muscle, Skeletal pathology, Muscular Atrophy pathology, Myocardial Contraction, Myocardium enzymology, Myocardium pathology, Myosin Heavy Chains genetics, Ventricular Function, Left, Volition, Creatine Kinase genetics, Muscle, Skeletal enzymology, Muscular Atrophy physiopathology, Physical Exertion physiology, Running physiology
- Abstract
The creatine kinase system (CK) is important for energy delivery in skeletal and cardiac muscles. The two main isoforms of this enzyme, cytosolic MM-CK and mitochondrial mi-CK, are expressed in a developmental and muscle-type specific manner. Mice deficient in one or both of these isoforms are viable and fertile but exhibit profound functional, metabolic and structural muscle remodelling that primarily affects fast skeletal muscles, which show an increased contribution of oxidative metabolism to contractile function. However, the consequences of these alterations in terms of physical capabilities have not yet been characterized. Consequently, we compared the voluntary exercise capacity of 9-month-old male wild-type (WT), M-CK knockout (M-CK(-/-)), and M-CK and mi-CK double knockout (CK(-/-)) mice, using cages equipped with running wheels. Exercise performance, calculated by total distance covered and by work done during the training period, was more than 10-fold lower in CK(-/-) mice than controls, with M-CK(-/-) mice exhibiting intermediate performance. Similarly, the mean distance run per activation was lower in M-CK(-/-) and even lower in CK(-/-) mice. However, the maximal running speed (V(max)) was lower only for CK(-/-) mice. This was accompanied by severe skeletal muscle mass decrease in CK(-/-) mice, with signs of histological damage that included enlarged interstitial areas, aggregations of mononuclear cells in the interstitium, heterogeneity of myofibre size and the presence of very small fibres. No overt sign of cardiac dysfunction was observed by magnetic resonance imaging during dobutamine stimulation. These results show that metabolic failure induced by CK deficiency profoundly affects the ability of mice to engage in chronic bouts of endurance running exercise and that this decrease in performance is also associated with muscle wasting.
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- 2005
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12. Energy metabolism in heart failure.
- Author
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Ventura-Clapier R, Garnier A, and Veksler V
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- Animals, Humans, Mitochondria, Heart metabolism, Energy Metabolism physiology, Heart Failure metabolism
- Abstract
Heart failure (HF) is a syndrome resulting from the inability of the cardiac pump to meet the energy requirements of the body. Despite intensive work, the pathogenesis of the cardiac intracellular abnormalities that result from HF remains incompletely understood. Factors that lead to abnormal contraction and relaxation in the failing heart include metabolic pathway abnormalities that result in decreased energy production, energy transfer and energy utilization. Heart failure also affects the periphery. Patients suffering from heart failure always complain of early muscular fatigue and exercise intolerance. This is linked in part to intrinsic alterations of skeletal muscle, among which decreases in the mitochondrial ATP production and in the transfer of energy through the phosphotransfer kinases play an important role. Alterations in energy metabolism that affect both cardiac and skeletal muscles argue for a generalized metabolic myopathy in heart failure. Recent evidence shows that decreased expression of mitochondrial transcription factors and mitochondrial proteins are involved in mechanisms causing the energy starvation in heart failure. This review will focus on energy metabolism alterations in long-term chronic heart failure with only a few references to compensated hypertrophy when necessary. It will briefly describe the energy metabolism of normal heart and skeletal muscles and their alterations in chronic heart failure. It is beyond the scope of this review to address the metabolic switches occurring in compensated hypertrophy; readers could refer to well-documented reviews on this subject.
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- 2004
- Full Text
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13. Activated and rigor tensions in rat papillary muscle [proceedings].
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Vassort G and Ventura-Clapier R
- Subjects
- Animals, Calcium pharmacology, In Vitro Techniques, Oxygen pharmacology, Papillary Muscles drug effects, Papillary Muscles physiology, Potassium pharmacology, Rats, Sodium pharmacology, Myocardial Contraction drug effects
- Published
- 1979
14. Significance of creatine phosphate on the hypodynamic frog heart [proceedings].
- Author
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Vassort G and Ventura-Clapier R
- Subjects
- Adenosine Triphosphate metabolism, Animals, Anura, Calcium metabolism, In Vitro Techniques, Myocardial Contraction, Myocardium metabolism, Phosphocreatine metabolism
- Published
- 1977
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