The effect of glucagon on the carbon flux from palmitate into glucose, lactate and ketone bodies, studied with isolated hepatocytes.
Glucagon induced a rapid (within 3 min) increase in glucose radioactivity and a decrease in the labeling of ketone bodies when isolated hepatocytes were incubated in the presence of [1-14C]palmitate. Simultaneously, the hormone induced a decrease in the levels of pyruvate and Krebs cycle intermediates and an increase in the level of phosphoenolpyruvate (PEP). The glucagon-induced increase in glucose radioactivity was much larger than the simultaneous decrease in lactate labeling. A comparison of the incorporation of labeled carbon from [1-14C]palmitate and [U-14C]palmitate into glucose and CO2 indicates a selective stimulatory action of glucagon on the flux through the phosphoenolpyruvate carboxykinase (PEPCK) reaction.
D000818:Animals; D002250:Carbon Radioisotopes; D002952:Citric Acid Cycle / Q000187:drug effects; D005934:Glucagon / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D066298:In Vitro Techniques; D007657:Ketone Bodies / Q000378:metabolism*; D007700:Kinetics; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism*; D051381:Rats
D002250:Carbon Radioisotopes; D007657:Ketone Bodies; D007773:Lactates; D010169:Palmitic Acids; D019308:Palmitic Acid; D019344:Lactic Acid; D005934:Glucagon; D005947:Glucose