Role of the Ca2+ cycle in uncoupling of oxidative phosphorylation in liver mitochondria of cold-acclimated rats.
Cold acclimation of Wistar rats for 2-4 weeks at about 3 degrees C resulted in an increased respiration rate and a reduced ADP/O ratio in liver mitochondria. With increasing duration of acclimation up to 10-12 weeks, these parameters returned to a normal level. The increase in the respiration rate and the decline of the mitochondrial ADP/O ratio were associated with a significant activation of the electroneutral release of Ca2+. When the animals were acclimated for 10-12 weeks the rate of Ca2+ release reduced to control values. The addition of 1 microM ruthenium red resulted in a decrease in the rates of mitochondrial respiration in control and cold-acclimated rats to approximately equal values and in a partial restoration of the ADP/O ratio in liver mitochondria of rats kept in the cold for 2-4 weeks. The respiratory activity of mitochondria isolated in the presence of 1 mM EGTA unaffected by ruthenium red.
Brustovetsky
N N
NN
Maevsky
E I
EI
Kolaeva
S G
SG
Danilova
L S
LS
Solomonov
N G
NG
D000064:Acclimatization; D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003080:Cold Temperature; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D012430:Ruthenium Red / Q000494:pharmacology; D014475:Uncoupling Agents
D014475:Uncoupling Agents; D012430:Ruthenium Red; D000244:Adenosine Diphosphate; D002118:Calcium