Arachidonic acid causes cytochrome c release from heart mitochondria.
Arachidonic acid interaction with heart mitochondria is known to cause uncoupling as well as inhibition of pyruvate + malate and succinate-supported respiration. Here we present experiments showing that arachidonic acid causes cytochrome c release from Ca(2+)-loaded heart mitochondria. We have also measured mitochondrial matrix swelling and found a fairly good correlation between the two processes, as revealed by the same arachidonic acid concentration dependence and by the same susceptibility toward different free fatty acid species. The effects produced by arachidonic acid are not related to its protonophoric activity since, under the experimental conditions used, saturating concentrations of FCCP did not cause any effect.
Di Paola
M
M
Department of Medical Biochemistry and Biology, University of Bari, Bari, Italy.
Cocco
T
T
Lorusso
M
M
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D019069:Cell Respiration / Q000187:drug effects; D003574:Cytochrome c Group / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011522:Protons; D051381:Rats; D017208:Rats, Wistar; D013053:Spectrophotometry
D003574:Cytochrome c Group; D011522:Protons; D016718:Arachidonic Acid; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D002118:Calcium