Oxidative phosphorilation

Ultrastructure, tissue respiration and oxidative phosphorilation were studies in the myocardium of animals after chronic natural irradiation by 137Cs in quantities that can in reality threaten population of radionuclide-polluted regions. Decline in the respiratory activity of the myocardium and ultrastructural disorders can be attributed to the effects of ions of radioactive Cs which is also a potassium antagonist. A hypothesis has been put forward according to which cesium blocks potassium channels in mitochondria and thus changes the volume and configuration of internal mitochondrial membranes, and impacts the respiratory processes...

The influence of L-arginine (600 mg/kg) and NO-synthase blocator N omega-nitro-L-arginine L-NNA (35 mg/kg) on processes of ADP-stimulated respiration (under using 0.35 mM succinate, 1 mM alpha-ketoglutarate, 2 mM pyruvate, 2 mM glutamate, 2 Mm malate and succinate dehydrohenase blocator--2 mM malonate as substrates of oxidation), lipid peroxidation (concentration of DK and MDA), activities of succinate dehydrohenase and aminotransferases in rats tissues with different resistance to hypoxia under stress conditions have been investigated...

The glutathione-reductase and glutathione-S-transferase activities in the cortex and brain stem tissues of rabbits with post-traumatic epileptic reality (1 year after the light brain injury) was defined. An increase of glutathione-reductase activity in the cortex microsomal and stem mitochondrial fractions, and increase of glutathione-S-transferase activity in cortex and stem mitochondrial fractions was obtained. The conclusion is made that the activation of the anti-oxidant glutathione fermentative system is a long-term metabolic CNS adaptation in the case while mitochondrial oxidation and oxidative phosphorilation are disturbed...

Changes in the energetic metabolism in the cortex were examined in bemegride-kindled rabbits. A reliable decrease in the ATP and an increase in the AMP contents in the cortical tissues as well as low ATP/AMP and energetic charge coefficients have been found after kindling the rabbits for 14 and 30-days as compared to the control groups of animals. Considerable disorders in the oxidative phosphorilation in the mitochondria of the cortical tissues have been determined after the succinate and glutamate oxidation: a decrease in the oxygen utilization rate at V3 active metabolic state, lowering the respiratory control coefficient and the disscciation between phosphorilation and oxidation...

Postradiation DNA breaks activate the repair enzyme, Adenosine diphosphoribosil transferase, which consumes NAD as a substrate and causes neuronal NAD and then ATP pool depletion; here this is considered to be the crucial links of the cerebral radiation syndrome (CRS) mechanism. Two ways of its metabolic correction were examined: (a) prevention of postradiation NAD depletion by administration of the enzyme inhibitor and (b) shunting NAD-dependent oxidative phosphorilation path of ATP resynthesis by administration of substrate of NAD-independent oxidation...

Mitochondria are cellular organelles that have the function of the oxidative phosphorilation and the formation of ATP. In humans, the mtDNA is a double-stranded, circular, covalent closed molecule of 16.5 kb. The mtDNA is inherited as a haploid from the mother and heteroplasmy has been found rarely. From a populational perspective, it could be considered as a system of small, sexually isolated demes, or clonal lineages, with an evolutionary rate 5 to 10 times faster than the nuclear genome. All these characteristics make this molecule ideal for evolutionary studies...

The influence of a new surgical absorbable material Biofil on the energetical metabolism processes, contents and ratio of the nucleic acids in the operated kidney tissue was studied in experiment. The oxidizing phosphorylation inhibition, the RNA content and RNA/DNA coefficient lowering were noted on the 14th day after the catgut thread application in a sutured tissues. The phosphorilizing respiration activation, the respiration control and RNA synthesis rising were promoted by biofil application. It had a significance for stimulation of regeneration processes in kidneys and for more early restoration of their function...

1. When added to the Na(+)-containing solution bathing the isolated toad skin, dinitrophenol (DNP, an uncoupler of oxidative phosphorilation) caused decreases in the baseline values of short circuit current (SCC) and transepithelial conductance (G). 2. DNP also inhibited the increases in SCC and G caused by theophylline, whether added prior to the xanthine, or after the effect of the latter was fully developed. 3. In skins exposed to theophylline and bathed in Cl(-)-free (sulfate Ringer's) solution, the changes in SCC and G had a similar time course (t1/2 > 15 min)...

The favourable effect of gentamicin and its combination with furosemid was shown in treatment of rats with experimental pyelonephritis. However, alongside the favourable effect, a danger of the gentamicin nephrotoxic effect, especially in combination with furosemid was noted. The nephrotoxic effect was evident from foci of distrophic and necrobiotic changes in the epithelium of the convoluted tubules, impairment of the cortical hemodynamics and development of the cortical hypoxia of the kidneys resulting in severe renal insufficiency...

The author examined the influence of the preparation stenopryl on the processes of oxidative prosphorilation in the liver and cerebral mitochondria of a rat in view of clarifying some aspects of its pharmacobiochemical mechanism. The results from the experiments in vitro revealed that stenopryl inhibited the processes of oxidative phosphorilation in comparatively high concentrations. The lower concentrations of the preparation did not induce changes. Stenopryl used in vitro, raised ATP-ase activity in liver mitochondria...

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Morphology, urinary enzyme excretion and mitochondrial function was studied in rats fed over a period of 30 days with 20 and 40 mg CsA/kg body weight. Already on day 8 vacuolisation and augmentation of autophagic vacuoles, lipid droplets and a loss in microvilli can be observed in the S-3 segment of the proximal nephron using the lower CsA dose. These effects are enhanced during the treatment period. The overall effect, however, is a subtle one. The dose of 40 mg/kg produces more pronounced cellular alterations, a more severe vacuolisation, but also focal prenecrotic damage of proximal tubular S-2 and S-3 cells...

Succinic dehydrogenase (SDH) activity of the isolated mitochondria myocardial cells in chronic cardiac insufficiency was studied experimentally. The highest SDH values were found in the mitochondria of condensed type. The activity of the enzyme was low in the ordinary (orthodox) mitochondria. The medium SDH activity was registered in the intermediary type of mitochondria. The ordinary and the intermediary types of mitochondria prevailed in the fraction under study reflecting a fall of the SDH activity in the myocardial tissue...

Experiments on isolated functioning hearts of rats established that under equal filling pressure the hearts of the animals who are adapted to the periodic effect of hypoxy develop a higher force and rate of contractions; ultimately, the contractile function of such hearts, as calculated per unit of myocardial mass and unit of time, appears to be increased by 1/3. Oxygen consumption by the hearts of adapted animals does not much differ from the control values, and consequently, the efficiency of oxygen utilization increases approximately by 1/3...

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Neomycin (paromomycin) phosphotransferase was isolated from the mycelium and fermentation broth filtrates of Act. fradiae. The substance was partially purified by means of fractionation with ammonium sulphate followed by gel-filtration through Sefadex G-100. The extracellular and intracellular forms of the enzyme had the same substrate specificity and used only neomycin and paromomycin as substrates. The other aminoglycosides, including kanamycins A and B, lividomycin and ribostamycin were not used. The both forms had the same thermolability...

The effect of PEBG on respiration and oxidative phosphorilation (succinate as substrate) has been studied in liver mitochondria of rat treated with glucagon. The results obtained indicate that, while glucagon, as reported by others, induce a significant increase of respiration rate in state 3 (+ ADP), PEBG, at pharmachological dose, antagonizes this effect. The conclusion is that PEBG exertes its hypoglycemic activity by inhibiting the gluconeogenic reactions promoted by glucagon. This is strongly evident in diabetic or starwed conditions...

Specific proteins and phosphopeptides of nervous tissue soluble in acidified organic solvents have been shown to have an active participation in the metabolism of ammonia. Nitrogen phosphopeptides (amides) bound to phosphate residues which are non stable in acids. It was shown that acid-labil nitrogen (amide group) of phosphopeptides, bound to phosphate risidue, participates in the metabolism of ammonia formed during the oxidative deamination of amino acids. The data obtained indicate that 3'--5'-AMP dependent proteinkinase participates in the phosphorilation of phosphopeptides...

Electron microscopic observation was made on the outer fasciculata cells in the adrenal cortex of hypophysectomized rats receiving 10 mg of FAD and/or 0.3 mg of ACTH intraperitoneally once a day for 5 consecutive days from 24 hours after hypophysectomy. The simultaneous administration of FAD and ACTH to the hypophysectomized rat was more effective for preventing adrenocortical atrophy induced than the administration of ACTH alone. This effect appeared as clear cells with low electron density. While the characteristics induced by hypophysectomy were the decrease in number of smooth-surfaced endoplasmic reticulum (SER) and mitochondria and also crista of mitochondria being tubular...

The influence of central cholinolytic cyclosil on the oxidative phosphorilation, ATPase activity and ultrastructure of hepatic mitochondria has been studied. The increased effectivity of mitochondrial macroergic compounds formation in the presence of cyclosil (0.04 mg/ml) was noticed. The oxygen consumption rate of these particles did not change. These findings and the electron microscopic observations on mitochondrial swelling in the presence of the cholinolytic agent suggest that cyclosil enchances the degree of mitochondrial energization...