Stimulation of Oxygen Consumption by Oxaloacetate and Malate In the early 1930s, Albert Szent-Gyrgyi reported the interesting observation that the addition of small amounts of oxaloacetate or malate to suspensions of minced pigeon breast muscle stimulated the oxygen consumption of the prepara- tion. Surprisingly, the amount of oxygen consumed was about seven times more than the amount necessary for complete oxidation (to CO and HO) of the added oxaloacetate or malate. Why did the ad- dition of oxaloacetate or malate stimulate oxygen consumption? Why was the amount of oxygen consumed so much greater than the amount necessary to completely oxidize the added oxaloacetate or malate?