Studies of copper ion-induced mitochondrial swelling in vitro.
1. A study of the mode and mechanism of Cu(2+)-induced mitochondrial swelling was carried out. 2. Mitochondrial swelling curves (E(520) turbidity changes) were obtained as a function of [Cu(2+)], pH, temperature and mitochondrial protein concentration. ED(50) was approx. 70mmumoles of Cu(2+). Calculation of the activation energy from the Arrhenius equation gave a value of 22900cal./mole per degree with Q(10) 4.02. 3. No lipid peroxides were formed during swelling. 4. Changes in oxygen consumption (Clark-type electrode) were dependent on the substrate used, but revealed no increased uptake in presence of Cu(2+). 5. Cu(2+)-induced swelling was inhibited by EDTA, 8-hydroxyquinoline, cyanide, citrate, bovine serum albumin, ATP, glutamate, GSH, dithiothreitol and sucrose. Azide, Amytal, antimycin A and oligomycin had no significant effect. Potentiation of swelling was seen with ascorbate, 2,4-dinitrophenol and succinate. 6. The occurrence of different types of mitochondrial swelling and the suggestion that Cu(2+)-induced swelling is mediated through a stoicheiometric interaction with a thiol-containing membrane receptor are discussed.
D000255:Adenosine Triphosphate; D000818:Animals; D001205:Ascorbic Acid; D002614:Chelating Agents; D003300:Copper / Q000494:pharmacology*; D005971:Glutamates; D005977:Glutarates; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008055:Lipids; D008670:Metals; D008930:Mitochondria, Liver / Q000187:drug effects*; D010100:Oxygen / Q000494:pharmacology; D010101:Oxygen Consumption; D010545:Peroxides; D051381:Rats; D013053:Spectrophotometry; D013386:Succinates; D013696:Temperature; D013997:Time Factors
D002614:Chelating Agents; D005971:Glutamates; D005977:Glutarates; D008055:Lipids; D008670:Metals; D010545:Peroxides; D013386:Succinates; D003300:Copper; D000255:Adenosine Triphosphate; D001205:Ascorbic Acid; D010100:Oxygen