Cells in culture are exposed to marked oxidative stress, H2O2 being one of the predominant agents. Pyruvate and other alpha-ketoacids reacted rapidly, stoichiometrically, and nonenzymatically with H2O2, and they protected cells from its cytolytic effects. All five human and murine cell types studied, both malignant and nonmalignant, released pyruvate at an initial rate of 35-60 microM/h/2.5 X 1...

Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support for infants and children with postoperative cardiopulmonary failure. Nutritional support is mandatory during ECMO although specific actions for substrates on the heart have not been delineated. Prior work shows that enhancing pyruvate oxidation promotes successful weaning from ECMO. Accordingly, we tested the hyp...

A method is described to measure the intracellular content of pyruvate and lactate in epididymal adipose tissue of the rat. The intracellular pyruvate concentration was approx. 330M. Intracellular pyruvate contents and the rates of pyruvate output were increased when NNN'N'-tetramethyl-p-phenylenediamine was added, and decreased in the presence of alanine. Insulin addition caused an increase in...

1. In isolated pancreatic islets, pyruvate causes a shift to the left of the sigmoidal curve relating the rate of insulin release to the ambient glucose concentration. The magnitude of this effect is related to the concentration of pyruvate (5--90 mM) and, at a 30 mM concentration, is equivalent to that evoked by 2 mM-glucose. Pyruvate also enhances insulin release in the presence of fructose, ...

protonation of the reactive intermediates generated in the raction between dalkyl acetylenedicarboxylates and triphenylphosphine by isonitrosoacetophenone leads to vinyltriphenylphosphonium salts, which undergo intramolecular wittig reaction to produce dalkyl 4-phenyl-n-hydroxypyrrole-2,3-dicarboxylates in moderate yields.

background: our purpose was to investigate propolis and its component caffeic acid phenethyl ester (cape) for their antioxidant effects on the brain tissue of rats exposed to ionizing radiation (ir). materials and methods: fifty-four male albino sprague-dawley rats, divided into six groups, were designed as normal control group, cranial irradiation of 5 gray alone, irradiation plus cape, irradi...

essential oils (eos) extracted from aerial parts of aster indamellus grierson, calamintha umbrosa benth. and erigeron annuus (l.) pres.were analyzed by gc, gc/ms. the major acetylenic constituent (cis-lachnophyllum ester) of e. annuus was isolated and characterized by 1h and 13c-nmr spectra. their toxicity and repellent effect against lipaphiserysimi was tested. oils of e. annuus and c. umbrosa...

Pyruvate has been shown to both stimulate and inhibit kidney pyruvate dehydrogenase, (PDH,) kinase activity. The present study investigates the inhibitory effect of pyruvate under conditions in which the stimulatory effect is invariant. Inhibition of PDH, kinase activity by dichloroacetate, a pyruvate analog, is also characterized. Both pyruvate and dichloroacetate are uncompetitive, hyperbolic...