CURRENT CONTROVERSIES IN CARBOHYDRATE-METABOLISM - DOES EVEN ORAL GLUCOSE LOADING OF FASTED SUBJECTS (A) ABOLISH GLUCOSE-6-PHOSPHATE FLUX (NO) (B) INDUCE NET GLYCOLYSIS IN THE DOG LIVER (DOUBTFUL)

It is still being claimed that liver glucose-6-phosphatase flux is tot ally suppressed by glucose loading of fasted subjects. The evidence fo r this is weak. More rigorous approaches invlove following the appeara nce of label in plasma glucose upon infusion of gluconeogenic tracers. Such studies indicate continued active glucose-6-phosphatase flux upo n glucose loading. a second controversy is whether glucose loading to long term lasted dogs produces net liver glycolysis. Isotopic data spe aks against this, while analytical balance studies seem to favor this. The question is, however, how representative is the sampling in the l eft common hepatic vein.