The metabolic response of brain slices to agents affecting the sodium pump

Abstract

Slices of brain cortex from rabbits were incubated in Ringer solution and in Ringer modified by the removal of Ca and Na, and the additionof ouabain, oligomycin or extra K. The K content of the tissue, the oxygen consumption and the lactate production from glucose were measured and found to be interrelated. Incubation in high-K Ringer caused an increase in oxygen consumption that was prevented by ouabain, oligomycin and deprivation of sodium. Lactate production was also raised, but this increase was unaffected by ouabain and raised further by oligomycin. Ca omission raised metabolism; the tissue K content was unaffected. Oligomycin always decreased oxygen consumption and raised lactate production further. The metabolic responses to Ca, K, ouabain and oligomycin depended on Na. After anerobic incubation, the tissue potassium concentration was still 5 times higher than that in Ringer. It was unaffected by oligomycin but lowered markedly by ouabain. The synergistic effects of Na with K, oligomycin, Ca, and Ca plus ouabain suggest that the metabolic responses of brain cortex slices to a high-K Ringer depend on the operation of the Na pump.