acetoacetate level is markedly raised it does not contribute to any increase in the third spot. The absence of any detectable acetoacetate spot is probably due to decarboxylation, both during the extraction process and during the run on the paper, and it was noticed that an acetone 2:4-dinitrophenylhydrazone spot was regularly seen on the chromatograms from the alloxan-treated animals. In view ...

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...

Cortisol markedly suppressed in vitro utilization of uridine-3 H by corticoid-sensitive mouse lymphoma P1798 cells. Corticoid-resistant cells were not affected. Inhibition did not depend on reduced uptake of exogenous carbohydrate precursors since similar effects were obtained in glucose-free, pyruvate-free medium. Omission of glucose and pyruvate per se did not influence uridine-3H uptake and ...

Pyruvate kinase activity in serum from presumably healthy individuals is labile, but can be maintained for a week when samples are stored frozen. Contrary to published data our electrophoretic and isoelectrofocusing studies with fresh sera show the presence of both K and M isoenzymes; the latter predominates. In freezer-stored serum the putative M isoenzyme showed a progressive decrease in pl v...

The influence of pH on the type and concentration of metabolites produced from pyruvate by Lactobacillus plantarum ATCC 8014 was examined in pH-controlled fermentors at pH values of 4.5 to 6.5. Specific growth rates, cell dry weights, and diacetyl concentrations were highest at pH 5.5, with values of 0.78 h, 190 mg/liter, and 1.2 mM, respectively. While the conversion efficiency (millimoles of ...

Levels of glycogen, lactate, pyruvate, total proteins, free amino acids andenzymes (LDH & SDH) have been recorded in brain, heart, kidney and liver of rats in response to treatment with crude drug combination. The study indicates increase in the levels of glycogen, pyruvate, total proteins, LDH and SDH and decrease in levels of lactate and free amino acids.

Microbial extracellular heteropolysaccharides are mainly linear molecules to which side chains of varying length and complexity are attached at regular intervals. Examination of 'families' of microbial exopolysacchaiide with closely related structures enables us to determine the effect of minor (or major) changes to structure on the physical properties of these macromolecules. Changes may also ...