[Fructose-2,6-bisphosphate system and experimental states].

The molecular mechanisms of the inhibitory action of fructose- 2,6-bisphosphate (F-2,6-P2) on fructose-1,6-biphosphatase (FB-Pase-1), the key enzyme of gluconeogenesis, and the those of the activating action of F-2,6-P2 on phosphofructo-1-kinase (PFK-1), the key enzyme of glycolysis, NMR spectroscopy first provided direct evidence for the fact that F-2,6-P2 was involved in the regulation of the sedoheptulose cycle of a nonoxidative stage of the pentosephosphate pathway. Procedures were developed in measuring the levels of F-2,6-P2 in the cell of experimental animal tissues and human blood lymphocytes. Naturally different emergencies substantially affected the F-2,6-P2 system by triggering these or those mechanisms controlling the activity of enzymes of this system. Vanadium-containing compounds were demonstrated to have a positive action on carbohydrate metabolism in diabetic (streptozotocin-induced) rat hepatocytes.