Abstract
The Krebs cycle in glomeruli of rat kidney was studied under normal conditions and in compensatory hypertrophy after unilateral nephrectomy. By using substrates of the cycle and measuring with the Cartesian diver technique the increase in oxygen uptake, it was established that the entire enzyme system is present, including succinic dehydrogenase. The latter could not be demonstrated by other authors who used older histochemical staining techniques. In compensatory hypertrophy it was thought sufficient to study activites of two enzymes only, isocitric dehydrogenase and succinic dehydrogenase. No change in the activity of either dehydrogenase was found. The conclusion was drawn that in hypertrophy, the glomeruli simply swell and serve as ultrafilters; the Krebs cycle is present, but produces ATP only for the maintenance of normal cell functions and thus does not undergo an increase in activity.