The metabolism of lactic and pyruvic acids in normal and tumour tissues

In the first two papers of this series [Elliott & Schroeder, 1934; Elliott et al. 1935], it was shown that, with slices of rabbit and rat kidney cortex, the disappearance of added lactic and pyruvic acids, and substances derived from them in the cycle of reactions involved in their oxidative breakdown, was more rapid than could be accounted for by oxidation. Some non-acid substance was apparently produced and it seemed likely that synthesis of carbohydrate took place. The previous work showed that kidney slices produced no glycogen from the sub- strates studied, but the work reported in this paper shows that definite increases in total carbohydrate occur when kidney tissue is incubated aerobically with lactate and pyruvate under conditions similar to those of the manometric experi- ments. Carbohydrate synthesis also occurs in kidney tissue from succinate, fumarate and malate; this is to be expected since the previous work had shown that these substances are converted into pyruvate by oxidation.