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Biomedical subjects

E Carafoli

Publications and source records attributed to E Carafoli.

At least 325 records · Page 18Linked to original sources
PubMed1969

The oxidation of exogenous and endogenous cytochromeC in mitochondria. A biochemical and ultrastructural study.

The effect of the nonionic detergent Lubrol on the oxidation of endogenous and exogenous cytochrome c by cytochrome oxidase in intact and fragmented mitochondria was studied. Mitochondria and mitochondrial fragments from liver, kidney, heart, and skeletal muscle have been used. Negatively stained preparations of intact mitochondria showed the particles of Fernández-Morán on the matrix side of their inner membrane system: under these conditions, the oxidation rate of externally added cytochrome c was very high, and it was stimulated very poorly by Lubrol. Mechanical fragmentation of liver mitochondria yielded vesicles with a smooth external profile: also under these conditions, the oxidation of externally added cytochrome c was very high, and poorly stimulated by Lubrol. The oxidation of endogenous cytochrome c was also unaffected by Lubrol. On the other hand, fragmentation of heart and skeletal muscle mitochondria yielded vesicles having numerous particles of Fernández-Morán on their external profiles. Under these conditions, the oxidation of exogenous cytochrome c was low and was markedly stimulated by Lubrol. On the contrary, no activation of the oxidation of endogenous cytochrome c was induced by the detergent. The results indicate a difference in the permeability properties of the two faces of the inner mitochondrial membrane: a permeability barrier for cytochrome c is suggested to exist at the inner face.

Amides↗
PubMed1967

In vivo effect of uncoupling agents on the incorporation of calcium and strontium into mitochondria and other subcellular fractions of rat liver.

After injection of (45)Ca(++) or (89)Sr(++) into rats, the largest part of the radioactivity in the liver cell is associated with the subcellular structures, only negligible amounts of it being found in the soluble hyaloplasm. 50 % or more of the (45)Ca(++) and (89)Sr(++) in the liver cell is recovered in the mitochondrial fraction. The specific activity of Ca(++) after injection of (45)Ca(++) is far greater in mitochondria than in microsomes. Pretreatment of the rats with uncouplers of oxidative phosphorylation markedly decreases the amount of radioactivity associated with the mitochondrial fraction. The amount of radioactivity recovered in the microsomes and in the final supernatant on the contrary increases. These effects are present only when mitochondrial oxidative phosphorylation is completely uncoupled. The Ca(++) content of mitochondria from the livers of rats pretreated with uncouplers is sharply decreased with respect to the controls. It is concluded that in the liver cells of the intact animal energy-linked movements of Ca(++) and Sr(++) take place in mitochondria.

Animals↗