Micromolar calcium prevents isolated rat liver mitochondria from anoxia-reoxygenation injury.
Rat liver mitochondria were exposed to extramitochondrial free calcium between 0 and 5 microM and/or 5 minutes of anoxia followed by 10 minutes of reoxygenation. At concentrations higher than 4 microM, the membrane potential collapsed indicating the permeability transition of the mitochondrial membrane. Anoxia-reoxygenation shifted this transition to lower calcium concentrations. Anoxia-reoxygenation alone resulted in the decrease of ADP stimulated respiration down to about 40% of its initial value. Between 1 and 2 microM, a protective effect in terms of respiration and oxidative protein modification was found. It is concluded that calcium may suppress the formation of reactive oxygen species during anoxia-reoxygenation before permeability transition occurs.
Schild
L
L
Department of Pathobiochemistry, Otto-von-Guericke-University, Medical Faculty, Magdeburg, Germany.
Plumeyer
F
F
Reinheckel
T
T
Augustin
W
W
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010100:Oxygen / Q000502:physiology*; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism
D017382:Reactive Oxygen Species; D010100:Oxygen; D002118:Calcium