title: Calcium accumulating ability of mitochondria from bovine coronary artery. Comparison with aortic mitochondria.
abstract: The calcium accumulating ability of mitochondria isolated both from bovine coronary artery and aorta was investigated. Coronary artery and aorta were pretreated with 0.1% collagenase. Cytochrome c oxidase activities of mitochondria isolated from coronary artery and aorta showed 25-fold and 19-fold increases, respectively, as compared with those of each homogenate, whereas NADPH-cytochrome c reductase, potassium-phosphatase and Na+-K+ ATPase activities increased less than 2-fold. This suggests that the isolation procedure is capable of obtaining a subcellular fraction highly enriched with mitochondria. Mitochondrial calcium uptake activity of the coronary artery was approximately 250 nmoles Ca2+/mg protein/10 min, and was markedly depressed with metabolic inhibitors such as NaN3, ruthenium red and 2,4-dinitrophenol. Calcium uptake activity of bovine aortic mitochondria showed similar activity and a similar trend in sensitivity to metabolic inhibitors. By contrast, the onset of the calcium binding reaction of the aortic mitochondria was slower and the azide-sensitivity of the mitochondria to magnesium ATPase activity was lower than those for coronary artery mitochondria. The present study has provided a method for isolation of mitochondria with a high capacity of calcium uptake activity, which may prove meaningful for future physiological and pharmacological evaluation of mitochondrial calcium accumulation in vascular smooth muscle.
authors.forename: S
authors.initials: S
authors.lastname: Takeo
authors.forename: M
authors.initials: M
authors.lastname: Sakanashi
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000648:ultrastructure*; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D003331:Coronary Vessels / Q000648:ultrastructure*; D003470:Culture Media; D003576:Electron Transport Complex IV / Q000378:metabolism; D066298:In Vitro Techniques; D003012:Microbial Collagenase / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D003470:Culture Media; D003576:Electron Transport Complex IV; D000469:Alkaline Phosphatase; D003012:Microbial Collagenase; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium