The respiration of rat brain mitochondria purified by phase partition. Effects of K+, Mg2+ and Ca2+.
Highly purified brain mitochondria have been prepared by Na+, NH4+ or K+-containing two-phase systems. K+ stimulated the basal rate of respiration in the three mitochondrial preparations. However, K+ only stimulated the maximal oxidation rate (state 3 respiration rates) in those mitochondria prepared by K+-free (Na+ or NH4+-containing) two-phase systems. The increase in the basal rates of respiration induced by exogenous K+ correlates with the mitochondrial swelling rates. The stimulatory effect of K+ on maximal oxidation rates seems to reflect the K+ depletion of brain mitochondria when prepared by K+-free procedures.
D000641:Ammonia / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D008928:Mitochondria / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats
D000641:Ammonia; D011188:Potassium; D002118:Calcium