title: Small scale preparation of skeletal muscle mitochondria, criteria of integrity, and assays with reference to tissue function.
abstract: Mitochondria prepared in small scale from skeletal muscle were studied with respiration measurements and low temperature spectroscopy. The method of preparation was developed for 25-100 mg tissue with pigeon breast muscle as model organ. The yield was 40%. Data collected during the developmental work were used to evaluate criteria of mitochondrial quality. The cytochrome c conservation, i.e. cytochrome c per mitochondrial quantity in the preparation relative to that in the tissue, is a most useful test parameter. It is bounded between 0-100%. Proportionality between the state 3 rate and the cytochrome c conservation was not rejected by statistical tests. The respiratory control ratio (RCR) was also highly correlated to the cytochrome c conservation. These correlations might be extrapolated to 100% conservation to give hypothetical tissue values. The cause for the correlations is discussed. The P/O ratio showed only weak dependence on the cytochrome c conservation and the state 4 rate showed no dependence. Other, rather insensitive test parameters are also discussed. The pigeon breast muscle mitochondria isolated by the final method showed cytochrome c conservation of 73 +/- 9% (n = 16). They are compared with pig biceps femoris mitochondria prepared by the same method. The two types of mitochondria show many similarities. Some differences may be explained by a different amount of inner mitochondrial membrane relative to mitochondrial protein. The pig tissue contains ten times less mitochondrial protein than the pigeon tissue does.
authors.affiliation: Department of Biochemistry, August Krogh Institute, University of Copenhagen, Denmark.
authors.forename: H N
authors.initials: HN
authors.lastname: Rasmussen
authors.forename: U F
authors.initials: UF
authors.lastname: Rasmussen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D010856:Columbidae; D003574:Cytochrome c Group / Q000032:analysis*; D004579:Electron Transport; D008931:Mitochondria, Muscle / Q000378:metabolism* / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D003574:Cytochrome c Group; D000255:Adenosine Triphosphate