English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Addition of t-butyl hydroperoxide to isolated perfused rat liver leads to a decreased flux through pyruvate dehydrogenase, shown by a decreased 14CO2 release from [1-14C]pyruvate. The effect is observed at rates of infusion of t-butyl hydroperoxide exceeding 0.7 mumol per min per g liver in normal livers and at significantly lower rates in glutathione-depleted livers. The effect is absent in livers from Se-deficient rats in which the hepatic Se-dependent glutathione peroxidase activity is very low, indicating that reduction of t-butyl hydroperoxide by glutathione peroxidase is a necessary prerequisite for the inhibition. With isolated mitochondria, decreased 14CO2 release from [1-14C]pyruvate during t-butyl hydroperoxide metabolism correlates with decreased GSH and increased GSSG contents, respectively. The addition of various disulfide compounds, including GSSG, inhibits activity of the enzyme in mitochondrial extracts. In both mitochondria and perfused liver, t-butyl hydroperoxide-mediated decrease of pyruvate dehydrogenase flux is relieved by thiol reductants. The active (dephospho)form of pyruvate dehydrogenase as measured in freeze-stopped liver samples is actually increased from 46% to 72% during t-butyl hydroperoxide metabolism. The tissue levels of ATP and ADP and perfusate beta-hydroxybutyrate/acetoacetate ratio are not markedly perturbed by addition of the hydroperoxide (10 min). It is concluded that the decreased flux through pyruvate dehydrogenase during t-butyl hydroperoxide metabolism results from oxidation of critical thiol group(s) of the enzyme complex consequential to a decrease in mitochondrial GSH/GSSG.

Decreased Flux through Pyruvate Dehydrogenase by Thiol Oxidation during t-Butyl Hydroperoxide Metabolism in Perfused Rat Liver