Depolarization-induced changes in cellular energy production.
Addition of high concentrations of KC1 to preparations of rat brain synaptosomes incubated with either glucose or pyruvate caused a transient stimulation of oxygen uptake. This increased respiration was insensitive to 1 mM ouabain and 10 microM ruthenium red but was dependent upon the presence of calcium. With 40 mM KCl in the incubation medium, the levels of high-energy phosphate compounds in the synaptosomes were unaltered, whereas pyridine nucleotides underwent a rapid, albeit small and temporary, oxidation. It is postulated that there is a calcium-dependent mechanism in synaptosomes through which the function of the mitochondrial respiratory chain or of oxidative phosphorylation is stimulated directly without the involvement of either adenine nucleotides or mitochondrial dehydrogenases.
Erecińska
M
M
Department of Pharmacology, University of Pennsylvania, School of Medicine, Philadelphia 19104-6084.
Nelson
D
D
Chance
B
B
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000502:physiology*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D003401:Creatine / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects*; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects*; D010725:Phosphocreatine / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012430:Ruthenium Red / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
D010725:Phosphocreatine; D012430:Ruthenium Red; D010042:Ouabain; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D003847:Deoxyglucose; D003401:Creatine; D002118:Calcium