Glucose, lactate, and ketone body utilization by human mammary carcinomas in vivo.

The glucose uptake rate of human mammary carcinomas transplanted into nude rats is comparable to values obtained in isotransplanted rodent tumors. The glucose uptake decreases with increasing tumor wet weight and is linearly related to the glucose availability. Most tumors release lactate, the rate being linearly related to the glucose uptake rate. Tumors use acetoacetate and beta- hydroxybutyrate as substrates. Additionally, human mammary carcinomas may have the ability for ketogenesis probably depending on the metabolic state. Using the epigastric pouching technique, human mammary carcinoma xenografts in nude rats seem to be a valid model for systematic investigations of the energy supply of human tumors.