Acute increases in the concentration of malonyl-CoA play a pivotal role in mediating the decrease in fatty acid oxidation that occurs in many tissues during refeeding after a fast. In this study, we assess whether such increases in malonyl-CoA in liver could be mediated by malonyl-CoA decarboxylase (MCD), as well as acetyl-CoA carboxylase (ACC). In addition, we examine how changes in the activi...

The alterations of enzymatic activities involved in lipid degradation in cancer cachexia have not been fully elucidated. One of the two subclones of colon 26 adenocarcinoma, clone 20, with a potent ability to induce cachexia, or clone 5, without such an activity, was transplanted in to CDF-1 male mice. Murine livers were extirpated for analyses on the 14th day after tumor inoculation. The body ...

We reported previously that a substantial fraction of the acetyl groups used to synthesize malonyl-CoA in rat heart is derived from peroxisomal beta-oxidation of long-chain and very-long-chain fatty acids. This conclusion was based on the interpretation of the 13C-labelling ratio (malonyl-CoA)/(acetyl moiety of citrate) measured in the presence of substrates that label acetyl-CoA in mitochondri...

Inhibition of mitochondrial carnitine palmitoyltransferase I (CPT I) by malonyl-CoA, the product of the acetyl-CoA carboxylase reaction, was first recognized in 1977 during the course of studies on hepatic ketogenesis and its regulation [ l ] . What emerged from that work was that with carbohydrate feeding (high insulin/low glucagon) the liver is actively engaged in fatty acid biosynthesis, the...

A yeast system differs only in that the major product is stearylCo.4 (5, 6) rather than the free fatty acid, palmitate, as in the other systems. The fatty acid synthetase reaction appears to be a multistage reaction catalyzed by a particulate enzyme complex estimated to have a molecular weight of 2,000,OOO in yeast (6) and to be readily sedimentable by ultracentrifugation in adipose tissue (4) ...

In this issue of the JCI, Rasmussen et al. (1) describe the functional regulation of fatty acid oxidation by hyperglycemia and hyperinsulinemia in human skeletal muscle. The authors report inhibition of long-chain fatty acid (LCFA) oxidation, but not medium-chain fatty acid (MCFA) oxidation, in association with increased intramyocellular malonyl-CoA concentrations. Normally, a glucose infusion ...

A yeast system differs only in that the major product is stearylCo.4 (5, 6) rather than the free fatty acid, palmitate, as in the other systems. The fatty acid synthetase reaction appears to be a multistage reaction catalyzed by a particulate enzyme complex estimated to have a molecular weight of 2,000,OOO in yeast (6) and to be readily sedimentable by ultracentrifugation in adipose tissue (4) ...

As theophylline is known to stimulate lipolysis and lipid mobilisation, plasma concentrations of malonyl dialdehyde were studied in asthmatic patients being treated with sustained release theophylline. Malonyl dialdehyde was assessed as malonyl dialdehyde like material (MDA-LM) by the thiobarbituric acid assay. In a kinetic study (eight patients) plasma MDA-LM concentrations were found to be si...

The American diet, especially that of adolescents, contains highly palatable foods of high-energy content and large amounts of high-fructose sweeteners. These factors are believed to contribute to the obesity epidemic and insulin resistance. Previous investigations revealed that the central metabolism of glucose suppresses food intake mediated by the hypothalamic AMP-kinase/malonyl-CoA signalin...