Spectral changes in the respiratory chain of cerebral cortex slices. Correlation with the energy status of the tissue.

Elevation of the media potassium concentration results in an immediate, but transient increase in the rate of respiration in cerebral cortex slices of the rat. As the respiratory burst decrease in intensity, a transient oxidation of the tissue respiratory intermediates is followed by a net reduction. The burst of respiration is accompanied by a large decrease in tissue ATP and phosphocreatine concentrations. ATP and phosphocreatine concentrations are essentially fully recovered within 5-6 min. The apparent increase in ATP hydrolysis during the peak of the respiratory response was not, however, accompanied by increases in the tissue content of ADP and 5'-AMP. Increased deamination of the adenine nucleotides is discussed as a possible mechanism in the large contraction of the total adenine pool observed during the course of the metabolic response to elevated potassium concentrations.