title: Mitochondria: isolation, structure and function.
abstract: Mitochondria are complex organelles constantly undergoing processes of fusion and fission, processes that not only modulate their morphology, but also their function. Yet the assessment of mitochondrial function in skeletal muscle often involves mechanical isolation of the mitochondria, a process which disrupts their normally heterogeneous branching structure and yields relatively homogeneous spherical organelles. Alternatively, methods have been used where the sarcolemma is permeabilized and mitochondrial morphology is preserved, but both methods face the downside that they remove potential influences of the intracellular milieu on mitochondrial function. Importantly, recent evidence shows that the fragmented mitochondrial morphology resulting from routine mitochondrial isolation procedures used with skeletal muscle alters key indices of function in a manner qualitatively similar to mitochondria undergoing fission in vivo. Although these results warrant caution when interpreting data obtained with mitochondria isolated from skeletal muscle, they also suggest that isolated mitochondrial preparations might present a useful way of interrogating the stress resistance of mitochondria. More importantly, these new findings underscore the empirical value of studying mitochondrial function in minimally disruptive experimental preparations. In this review, we briefly discuss several considerations and hypotheses emerging from this work.
authors.affiliation: Department of Kinesiology and Physical Education, McGill University, Montreal, Qc, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Picard
authors.forename: Tanja
authors.initials: T
authors.lastname: Taivassalo
authors.forename: Gilles
authors.initials: G
authors.lastname: Gouspillou
authors.forename: Russell T
authors.initials: RT
authors.lastname: Hepple
mesh_terms: D000818:Animals; D002458:Cell Fractionation / Q000379:methods*; D019069:Cell Respiration / Q000502:physiology; D006801:Humans; D008931:Mitochondria, Muscle / Q000502:physiology* / Q000648:ultrastructure*; D033681:Mitochondrial Membrane Transport Proteins / Q000502:physiology; D051336:Mitochondrial Membranes / Q000502:physiology; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species