On the mechanism of oligomycin inhibition of Ca(2+)-induced mitochondrial respiration.
The addition of oligomycin in the presence of Ca2+ increased the ADP pool in mitochondrial suspension. It is suggested that oligomycin inhibition of Ca(2+)-induced mitochondrial respiratory activation is the function of the increased endogenous ADP pool. Low ADP concentrations (5-20 microM) produce the same inhibitory effect as oligomycin. The increase of ADP levels in the presence of glucose plus hexokinase resulted in the inhibition of Ca(2+)-induced respiration, while the addition of phosphoenol pyruvate plus pyruvate kinase followed by a reduction in ADP levels, reversed the oligomycin inhibitory effect. One of the essential stages of ADP accumulation in mitochondrial suspensions in the presence of oligomycin and Ca2+ is proposed to be the formation of ADP from AMP and ATP, effected by adenylate kinase.
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, USSR.
I P
IP
Krasinskaya
I A
IA
Kudryashova
L S
LS
Yaguzhinsky
D000227:Adenine Nucleotides / Q000378:metabolism*; D000263:Adenylate Kinase / Q000378:metabolism; D000818:Animals; D001278:Atractyloside / Q000031:analogs & derivatives / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism; D009840:Oligomycins / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats
D000227:Adenine Nucleotides; D009840:Oligomycins; D001278:Atractyloside; D000226:Mitochondrial ADP, ATP Translocases; D000263:Adenylate Kinase; C003853:carboxyatractyloside; D002118:Calcium