The response of key gluconeogenic enzymes in bovine liver to various dietary and hormonal regimes

Abstract

SUMMARYThe effects of starvation, glucocorticoid administration, and the feeding of an all-concentrate diet, on the 14CO2-fixing activities of pyruvate carboxylase (EC. 6.4.1.1), phosphopyruvate carboxylase (EC. 4.1.1.32) and propiony1-CoA carboxylase (EC. 6.4.1.3) were measured in liver from lactating cows. Starvation caused a 26% decrease in propiony1-CoA carboxylase activity, glucocorticoid administration a 35% decrease in phosphopyruvate carboxylase activity, and the all-concentrate diet 24 and 41% increases in the activities of phosphopyruvate carboxylase and propiony1-CoA carboxylase respectively.