Influence of Dietary 1,3-Butanediol on Metabolites and Enzymes Involved in Gluconeogenesis and Lipogenesis in Rats

Abstract
The activities of malic and phosphoenolpyruvate carboxykinase (PEPcK) enzymes of 105,000 × g (1 hour) supernatants of liver and epididymal fat from rats fed 1,3-butanediol (BD) were examined. In animals fed a BD diet the liver PEPcK activity was increased. Malic enzyme activity in both liver and adipose tissue was the same with and without BD. Mitochondrial synthesis of precursors for gluconeogenesis from pyruvate and bicarbonate by liver pyruvate carboxylase was slightly increased in animals fed BD. All other metabolites remained unchanged. The concentrations of metabolites in liver and kidney were measured in animals fed a BD diet. There was an increase in 3-carbon phosphorylated intermediates in kidney but not liver. In both liver and kidney the lactate levels were lower in animals fed BD. The decrease in blood glucose levels in rats fed BD diets is attributed to the block of gluconeogenesis in kidney at the conversion of 3-phosphoglycerate to glyceraldehyde-3-phosphate. It is also suggested from malic enzyme activity that BD does not interfere with lipogenesis in liver and adipose tissues.