Maturation of potassium-stimulated respiration in rat cerebral cortical slices

Maximal dinitrophenol-stimulated respiration and K+-stimulated respiration were measured polarographically in cerebral cortical slices taken from rats aged 2-60 days. Increasing K+ concentrations produced an increase in respiration in slices from animals aged 15 days and older, but not in slices from animals aged 10 days and younger. Dinitrophenol-stimulated respiration, or the maximal respiratory capacity of the tissue, showed a similar increase between 10 and 15 days of age. At each age the maximal respiratory capacity was 6-8 ng at 0/mg protein min greater than the maximal K+-stimulated respiration.