The glycolytic flow in the skeletal muscle was considerably depressed during hibernation of Jaculus orientalis. 2. Although the ATP content was not modified, the ATP/AMP ratio was twice as large than under homeothermic conditions. 3. Furthermore, the hexose phosphates were markedly depressed. 4. The total activities of the key enzymes, hexokinase, phosphofructokinase and pyruvate kinase, which are regulated through the adenylates, decreased. 5. Under in vivo conditions, taking into account the small amount of fructose-6-phosphate and the ATP/AMP ratio, it is likely that phosphofructokinase was totally inhibited, explaining the undetectable amount of fructose 1.6 bisphosphate.
Purification and properties of glyceraldehyde-3-phosphate dehydrogenase from the skeletal muscle of the hibernating ground squirrel, Ictidomys tridecemlineatus.