Hormonal and metabolic response to physical exercise, fasting and cold exposure in the XXXX . Effects on ketogenesis in isolated hepatocytes.

@entity35 @entity1718 @entity6178 @entity2922
Four groups of @entity35 were subjected to the following conditions: (1) 48 h fasting, (2) 48 h of 4 degrees C cold exposure, (3) 5 h treadmill running, (4) 48 h fasting with 4 degrees C cold exposure. The groups were compared to fed control @entity35 in order to study hormonal and metabolic responses in blood and tissue samples. Isolated hepatocytes were used to evaluate the rate of ketogenesis. Decreases in liver glycogen and increases in blood free @entity1718 (FFA) confirmed that glycogenolysis and lipolysis occur in these situations of metabolic stress. Increases in the glucagon/insulin plasma ratio were also noted. Plasma @entity2922 levels were only enhanced after running and after cold exposure. Production of blood @entity6178 bodies was stimulated more by running and by fasting than by cold exposure. The low @entity6178 body production observed after cold exposure seems to be linked to increases liver glycogen levels and decreased FFA availability. Liver cells isolated after cold exposure exhibited higher ketogenesis than these isolated after running. This difference in ketogenic capacity could result both from the longer hormonal stimulation by high glucagon/insulin plasma ratios and from the metabolic state of the liver.
