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Difference between revisions of "Vielhaber 2000 Biochem Soc Trans"

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{{Publication
{{Publication
|title=Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS (2000) Muscle fibres: applications for the study of the metabolic consequences of enzyme deficiencies in skeletal muscle. Biochem. Soc. Trans. 28: 159-164.
|title=Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS (2000) Muscle fibres: applications for the study of the metabolic consequences of enzyme deficiencies in skeletal muscle. Biochem Soc Trans 28:159-64.
|info=[http://www.ncbi.nlm.nih.gov/pubmed/10816119 PMID: 10816119]
|authors=Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS
|authors=Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS
|year=2000
|year=2000
|journal=Biochem. Soc. Trans.
|journal=Biochem Soc Trans
|abstract=Mitochondrial function in saponin-permeabilized
|abstract=Mitochondrial function in saponin-permeabilized muscle fibres can be studied by high-Resolution respirometry, laser-excited fluorescence spectroscopy and fluorescence microscopy. We applied these techniques to study metabolic effects of changes in the pattern of mitochondrial enzymes in skeletal muscle of patients with chronic progressive external ophthalmoplegia or Kearns±
muscle fibres can be studied by high-resolution
Sayre syndrome harbouring large-scale deletions of mitchondrial DNA (mtDNA). In all patients combined deficiencies of respiratory chain enzymes containing mitochondrially encoded subunits were observed. The citrate synthase-normalized
respirometry, laser-excited fluorescence spectroscopy
activity ratios of these enzymes decreased linearly with increasing mtDNA heteroplasmy. This indicates the absence of any well-defined mutation thresholds for mitochondrial enzyme activities in the entire skeletal muscle. We applied metabolic control analysis to perform a quantitative estimation of the metabolic influence of the observed enzyme deficiencies. For patients with
and fluorescence microscopy. We applied
degrees of mtDNA heteroplasmy below about 60% we observed at almost normal maximal rates of respiration an increase in flux control coeficients of Complexes I and CIV. Permeabilized skeletal-muscle fibres of patients with higher degrees of mtDNA heteroplasmy and severe enzyme deficiencies exhibited additionally decreased maximal rates of respiration. This finding indicates the presence of a `metabolic threshold' which can be assessed by functional studies of muscle fibres providing the link to the phenotypic expression of the mtDNA mutation in skeletal muscle.
these techniques to study metabolic effects of
changes in the pattern of mitochondrial enzymes
in skeletal muscle of patients with chronic
progressive external ophthalmoplegia or Kearns±
Sayre syndrome harbouring large-scale deletions
of mitchondrial DNA (mtDNA). In all patients
combined deficiencies of respiratory chain enzymes
containing mitochondrially encoded subunits
were observed. The citrate synthase-normalized
activity ratios of these enzymes decreased
linearly with increasing mtDNA heteroplasmy.
This indicates the absence of any well-defined
mutation thresholds for mitochondrial enzyme
activities in the entire skeletal muscle. We applied
metabolic control analysis to perform a quantitative
estimation of the metabolic in¯uence of the
observed enzyme de®ciencies. For patients with
degrees of mtDNA heteroplasmy below about
60%we observed at almost normal maximal rates
of respiration an increase in flux control coeficients of complexes I and IV. Permeabilized skeletal-muscle fibres of patients with higher degrees of mtDNA heteroplasmy and severe enzyme deficiencies exhibited additionally decreased
maximal rates of respiration. This finding indicates the presence of a `metabolic threshold' which can be assessed by functional studies of muscle
fibres providing the link to the phenotypic ex-pression of the mtDNA mutation in skeletal muscle.
|keywords=Genotype, Phenotype relations, Mitochondrial (mt) myopathy, mtDNA deletion
|keywords=Genotype, Phenotype relations, Mitochondrial (mt) myopathy, mtDNA deletion
|info=[http://www.ncbi.nlm.nih.gov/pubmed/10816119 PMID: 10816119]
}}
}}
{{Labeling
{{Labeling
|topics=Respiration; OXPHOS; ETS Capacity
|area=Respiration, mtDNA;mt-genetics, mt-Medicine, Patients
|organism=Human
|tissues=Skeletal muscle
|preparations=Permeabilized tissue
|enzymes=Complex I, Complex IV;cytochrome c oxidase, Marker enzyme
|diseases=Inherited
|topics=Flux control, Threshold;excess capacity
|instruments=Oxygraph-2k
|instruments=Oxygraph-2k
|additional=Spectrophotometry; Spectrofluorimetry
}}
}}

Latest revision as of 14:44, 19 February 2015

Publications in the MiPMap
Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS (2000) Muscle fibres: applications for the study of the metabolic consequences of enzyme deficiencies in skeletal muscle. Biochem Soc Trans 28:159-64.

» PMID: 10816119

Vielhaber S, Kudin A, Schroder R, Elger CE, Kunz WS (2000) Biochem Soc Trans

Abstract: Mitochondrial function in saponin-permeabilized muscle fibres can be studied by high-Resolution respirometry, laser-excited fluorescence spectroscopy and fluorescence microscopy. We applied these techniques to study metabolic effects of changes in the pattern of mitochondrial enzymes in skeletal muscle of patients with chronic progressive external ophthalmoplegia or Kearns± Sayre syndrome harbouring large-scale deletions of mitchondrial DNA (mtDNA). In all patients combined deficiencies of respiratory chain enzymes containing mitochondrially encoded subunits were observed. The citrate synthase-normalized activity ratios of these enzymes decreased linearly with increasing mtDNA heteroplasmy. This indicates the absence of any well-defined mutation thresholds for mitochondrial enzyme activities in the entire skeletal muscle. We applied metabolic control analysis to perform a quantitative estimation of the metabolic influence of the observed enzyme deficiencies. For patients with degrees of mtDNA heteroplasmy below about 60% we observed at almost normal maximal rates of respiration an increase in flux control coeficients of Complexes I and CIV. Permeabilized skeletal-muscle fibres of patients with higher degrees of mtDNA heteroplasmy and severe enzyme deficiencies exhibited additionally decreased maximal rates of respiration. This finding indicates the presence of a `metabolic threshold' which can be assessed by functional studies of muscle fibres providing the link to the phenotypic expression of the mtDNA mutation in skeletal muscle. Keywords: Genotype, Phenotype relations, Mitochondrial (mt) myopathy, mtDNA deletion


Labels: MiParea: Respiration, mtDNA;mt-genetics, mt-Medicine, Patients  Pathology: Inherited 

Organism: Human  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue  Enzyme: Complex I, Complex IV;cytochrome c oxidase, Marker enzyme  Regulation: Flux control, Threshold;excess capacity 


HRR: Oxygraph-2k 

Spectrophotometry; Spectrofluorimetry