The activity of pyruvate dehydrogenase kinase in extracts of mitochondria from rat hepatocytes cultured for 21 h in medium 199 was increased 2.5-fold by the presence of 55 nM-glucagon and 1 mM-sodium n-octanoate in the culture medium. The change was comparable with that induced in vivo by 48 h starvation. The potential contribution of branched-chain complex to estimates of PDH-complex activity ...

Initial rate measurements of the stoichiometric relationships between H+ ejection, K+ and Ca2+ uptake, and electron transport were carried out on mitochondria from Ehrlich ascites tumor cells grown in mice. With succinate as substrate and N-ethylmaleimide to prevent interfering H+ reuptake via the phosphate carrier, close to 8 H+ were ejected per oxygen atom reduced (H+/O ejection ratio = 8.0);...

The turnover rates of the protein components of rat liver, kidney, and brain mitochondria were determined. In liver mitochondria, all protein components had an identical halflife of 8.5 days. In kidney mitochondria, the water-soluble proteins had a half-life of 5.9 days which was significantly shorter than that of the whole mitochondria, 8.6 days. The other protein components of kidney mitochon...

Alterations in liver mitochondria as consequence of rat poisoning with carbon tetrachloride (CCl4) have been reported over many years, but the mechanisms responsible for causing such damage are still largely unknown. Isolated rat liver mitochondria incubated under hypoxic conditions with succinate and ADP were found able to activate CCl4 to a free-radical species identified as trichloromethyl f...

The phosphate transport protein was purified from rat liver mitochondria by extraction in an 8% (v/v) Triton X-100 buffer followed by adsorption chromatography on hydroxyapatite and Celite. SDS/polyacrylamide-gel electrophoresis (10%, w/v) demonstrated that the purified polypeptide was apparently homogeneous when stained with Coomassie Blue and had a subunit Mr of 34000. However, lectin overlay...

Previously, we demonstrated that the endogenous glutamate receptor antagonist kynurenic acid dose-dependently and significantly affected rat heart mitochondria. Now we have investigated the effects of L-tryptophan, L-kynurenine, 3-hydroxykynurenine and kynurenic, anthranilic, 3-hydroxyanthranilic, xanthurenic and quinolinic acids on respiratory parameters (ie, state 2, state 3), respiratory con...

A novel endonuclease of 55-kDa was found in rat liver mitochondria by a zymographic assay, in addition to the 29 kDa enzyme that is well-known as endonuclease G (Endo G). Subcellular localization of these enzymes in rat liver cells was examined by biochemical fractionation. Endo G was located in both nuclei and mitochondria as has been previously reported, while the 55-kDa enzyme was only detec...

Besides the conventional isomerase-mediated pathway, unsaturated fatty acids with old-numbered double bonds are also metabolized by reduction pathways with NADPH as cofactor. The relative contributions of these pathways were measured in intact rat-liver and rat-heart mitochondria with a novel stable isotope tracer technique. A mixture of equal amounts of unlabelled cis-5-enoyl-CoA and 13C4-labe...

Azarashvili T, Krestinina O, Galvita A, Grachev D, Baburina Y, Stricker R, Evtodienko Y, Reiser G. Ca -dependent permeability transition regulation in rat brain mitochondria by 2 ,3 -cyclic nucleotides and 2 ,3 -cyclic nucleotide 3 -phosphodiesterase. Am J Physiol Cell Physiol 296: C1428–C1439, 2009. First published April 8, 2009; doi:10.1152/ajpcell.00006.2009.—Recent evidence indicates that 2...