01 September 2004
Enzymatic diagnosis of oxidative phosphorylation defects on muscle biopsy: Better on tissue homogenate or on a mitochondria-enriched suspension?
Jordi Casademont, Milagrosa Perea, Sonia Lopez, Anna Beato, Oscar Miro, Francesc CardellachMed Sci Monit 2004; 10(9): CS49-53 :: ID: 11751
Abstract
Background:The enzymatic analysis of mitochondrial respiratory chain (MRC) complexes of skeletal muscle is an important step in the diagnosis of mitochondrial disorders. Because of its lesser turbidity and increased sensitivity, mitochondrial fractionation has been increasingly considered the diagnostic method of choice compared with the more classical analysis of muscle homogenate. In circumstances in which mitochondria become abnormal in number, size or shape, the process of mitochondrial enrichment made by sequential centrifugation and washing may favor the selection of the most normal mitochondria, eliminating the most abnormal ones. In this situation, the study of muscle homogenate, paradoxically, may better reflect what happens in vivo.Case Report: To exemplify this situation we present a 60-year-old woman with a complete mitochondrial phenotype and a 70% heteroplasmic presence of the mtDNA A3243G mutation in muscle tissue. The respiratory and enzymatic activities from mitochondria-enriched muscle suspension were within normal control limits. In contrast, when muscle homogenate was studied, enzyme activities of complexes I, III, and V were found to be decreased.Conclusions: Although mitochondria-enriched muscle suspensions are usually more informative than muscle homogenates for studies of MRC, in some situations it may be necessary to study both to uncover the biochemical defect.
Keywords: Electron Transport Chain Complex Proteins - genetics, Biopsy, Brain - radiography, Cell Fractionation, DNA, Mitochondrial - analysis, Electron Transport, Electron Transport Chain Complex Proteins - metabolism, Mitochondria - ultrastructure, Mitochondrial Myopathies - physiopathology, Muscle, Skeletal - physiopathology, Oxidative Phosphorylation, Tissue Extracts - metabolism
Editorial
01 April 2024 : Editorial
Editorial: Forty Years of Waiting for Prevention and Cure of HIV Infection – Ongoing Challenges and Hopes for Vaccine Development and Overcoming Antiretroviral Drug ResistanceDOI: 10.12659/MSM.944600
Med Sci Monit 2024; 30:e944600
In Press
07 Mar 2024 : Clinical Research
Knowledge of and Attitudes Toward Clinical Trials: A Questionnaire-Based Study of 179 Male Third- and Fourt...Med Sci Monit In Press; DOI: 10.12659/MSM.943468
08 Mar 2024 : Animal Research
Modification of Experimental Model of Necrotizing Enterocolitis (NEC) in Rat Pups by Single Exposure to Hyp...Med Sci Monit In Press; DOI: 10.12659/MSM.943443
18 Apr 2024 : Clinical Research
Comparative Analysis of Open and Closed Sphincterotomy for the Treatment of Chronic Anal Fissure: Safety an...Med Sci Monit In Press; DOI: 10.12659/MSM.944127
08 Mar 2024 : Laboratory Research
Evaluation of Retentive Strength of 50 Endodontically-Treated Single-Rooted Mandibular Second Premolars Res...Med Sci Monit In Press; DOI: 10.12659/MSM.944110
Most Viewed Current Articles
17 Jan 2024 : Review article
Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron VariantDOI :10.12659/MSM.942799
Med Sci Monit 2024; 30:e942799
14 Dec 2022 : Clinical Research
Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase LevelsDOI :10.12659/MSM.937990
Med Sci Monit 2022; 28:e937990
16 May 2023 : Clinical Research
Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...DOI :10.12659/MSM.940387
Med Sci Monit 2023; 29:e940387
01 Jan 2022 : Editorial
Editorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...DOI :10.12659/MSM.935952
Med Sci Monit 2022; 28:e935952