100 



1. MALONATE 



injection of 12 millimoles/kg of malonate (Fig. 1-11). Maximal concentra- 

 tions of malonate are reached in most tissues 1-2 hr after the injection and 

 the time course of the succinate levels is well correlated with that of malo- 

 nate. The tissue succinate concentration is linearly related to the malonate 

 concentration, except in the Flexner-Jobling tumor (Busch and Potter, 



Fig. 1-11. Tissue levels of malonate and succinate 

 in rats injected with sodium malonate (12 milli- 

 moles/kg). (From Potter et al., 1952). 



1952 a) (Fig. 1-12). The slopes of the lines give some measure of the degree 

 of malonate effect in the particular tissue, but several factors are involved 

 so that they are not quantitative indications of succinate oxidase inhibition. 

 The urinary excretion of malonate, succinate, and citrate is shown in Fig. 

 1-13. The malonate and succinate levels in several normal tissues and tu- 

 mors following 24 millimoles/kg malonate subcutaneously are given in 

 Table 1-18. If the figures in the table are multiplied by approximately 

 0.7, one will obtain the millimolar concentrations in the cell water, except 

 for kidney and blood, the former tissue having extracellular fluid high in 

 succinate and malonate. 



The ratios of (succinate)/(malonate) in the tissues give essentially the 

 slopes of the lines in plots such as Fig. 1-12, except for tumors where a 



