Hepatocytes, isolated from fasted rats, were incubated with graded concentrations of lactate and pyruvate, at a mean constant ratio of 10-13:1, to alter systematically the concentrations of gluconeogenic intermediate metabolites and rates of glucose production. By analyzing glucose production rates as a function of corresponding concentrations of extracellular pyruvate, cytosolic oxalacetate, a...

1. Metabolism of pyruvate and malate by isolated fat-cell mitochondria incubated in the presence of ADP and phosphate has been studied by measuring rates of pyruvate uptake, malate utilization or production, citrate production and oxygen consumption. From these measurements calculations of the flow rates through pyruvate carboxylase, pyruvate dehydrogenase and citrate cycle have been made under...

Synechococcus sp. PCC 7002 is a unicellular cyanobacterium capable of fast growth and tolerance to high light intensity salinity. These attributes along with genetic tractability make an attractive candidate for industrial scale production specialty commodity chemicals. LS (Davies et al., Front Bioeng Biotechnol, 2014, 2, 21–11) produces limonene, energy dense diesel jet fuel drop-in additive, ...

Emissions of acetaldehyde from tree leaves were investigated by proton-transfer-reaction mass spectrometry (PTR-MS), a technique that allows simultaneous monitoring of different leaf volatiles, and confirmed by derivatization and high-performance liquid chromatography analysis. Bursts of acetaldehyde were released by sycamore, aspen, cottonwood and maple leaves following light–dark transitions;...

The proliferation of in vitro grown Ehrlich ascites tumor cells is inhibited by pyruvate concentrations greater than 2 mM. In the presence of 4-5 mM pyruvate the growth is reduced to about 50%, in the presence of 20 mM to about 5-10%. Viability of the cells is not severely affected. Increase of DNA corresponds to the cell growth. On recultivation in pyruvate free standard medium, growth is near...

The relative rate of pyruvate kinase synthesis in alloxan-diabetic rats was Y3 of that observed in controls and increased 3to 4-fold upon treatment with insulin for 3 days. Similar changes in the catalytic activity were observed: 120 + 40, 650 + 100, and 230 ± 79 units of pyruvate kinase/liver in diabetic rats, diabetic rats maintained on insulin for 3 days, and controls, respectively. Thus, ch...

Pyruvate carboxylation in the isolated perfused rat heart was studied under steady-state conditions. A biotin deficiency resulting in a 90% decrease in myocardial pyruvate carboxylase left the pyruvate carboxylation rate unchanged. Pyruvate carboxylation in heart muscle must therefore take place by means of an enzyme which does not contain biotin. The kinetic properties and mass-action ratio of...

In the heart, detection of hyperpolarized [(13)C]bicarbonate and (13)CO(2) by magnetic resonance (MR) after administration of hyperpolarized [1-(13)C]pyruvate is caused exclusively by oxidative decarboxylation of pyruvate via the pyruvate dehydrogenase complex (PDH). However, liver mitochondria possess alternative anabolic pathways accessible by [1-(13)C]pyruvate, which may allow a wider diagno...

1. The role of pyruvate carboxylation in the net synthesis of tricarboxylic acid-cycle intermediates during acetate metabolism was studied in isolated rat hearts perfused with [1-14C]pyruvate. 2. The incorporation of the 14C label from [1-14C]pyruvate into the tricarboxylic acid-cycle intermediates points to a carbon input from pyruvate via enzymes in addition to pyruvate dehydrogenase and citr...