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Biomedical subjects

V V Lemeshko

Publications and source records attributed to V V Lemeshko.

11 recordsLinked to original sources
PubMed1992

Decrease of phosphorylating oxidation and increase of heat producing NADH oxidation in rat liver mitochondria during life-span prolongation of rats by calorie-restricted diet.

The influence of calorie-restricted diet, initiated at weaning, on some of the oxidative processes in liver homogenates and isolated mitochondria of 2-, 3-, 4-, 24-, 35- and 45-month-old male Wistar rats was studied in comparison with control ad libitum-fed 1-2 day-old rats and 0.5-, 1-, 2-, 3-, 4- and 24-month-old rats. It was shown that a calorie-restricted diet (at 37% of the ad libitum calorific level) did not change the rate of succinate oxidation coupled with oxidative phosphorylation in homogenates, but resulted in a decrease of succinate, glutamate plus malate and beta-hydroxybutyrate oxidation and cytochrome c-oxidase activity in isolated mitochondria without any uncoupling of oxidative phosphorylation or change in cytochrome content in the mitochondria. On the other hand, a significant increase in mitochondrial rotenone-insensitive NADH oxidation and a higher liver mass/body mass ratio in rats under the calorie-restricted diet was established. It may be considered that the activation of a heat-producing mechanism is a very important physiological function in such a condition.

Aging↗
PubMed1991

[Age-related differences in the effect of osmotic pressure on liver mitochondrial respiration in rats].

The subject under investigation is the influence of osmotic pressure of incubation medium (25-500 mM of sucrose) upon the respiration and the respiration control (RC) of mitochondria of the liver of rats aged 1, 3, 12 and 24 months when oxidizing succinate. In a medium with 0.3 M of sucrose the respiration rate under condition 3 (V3) and RC increased from the age of 1 to 12 months and decreased by 24 months. In a medium with 0.15 M of sucrose the age differences have not been observed. In a uncoupling state the osmotic dependence of the respiration of mitochondria of 1- and 12-month-old rats did not vary. It is assumed that with age there is a change in the rate of structural coupling of the carrier of adenine nucleotides with H(+)-ATP synthetase complex and (or) the viscosity of the matrix.

Aging↗
PubMed1978

[Cryoresistance of rat liver endoplasmic reticulum membranes].

The effects of freezing of microsomes in liquid nitrogen and those of storage of microsomal suspensions at 2-4 degrees C and -3 - -5 degrees C for 24 hrs, on the enzymatic activities and hydrophobicity of membranes were studied. The hydrophobicity was determined by fluorescence of bound 1,8-anilino-naphthalene sulfonate. Rapid freezing of the microsomal suspension in liquid nitrogen followed by rapid warming did not change the hydrophobicity of the membranes, the rate of enzymatic lipid peroxidation, the level of cytochrome P-450 and the activity of NADH- and NADPH-cytochrome c reductase. A considerable decrease in the rate of enzymatic lipid peroxidation and membrane hydrophobicity was observed in the microsomes stored for 24 hrs at 2-4 degrees C. The 24-hr storage at -3 - -5 degrees C with subsequent thawing resulted in a rapid aggregation of the microsomes.

Adaptation, Physiological↗
PubMed1976

[Halidor, 1-benzyl-1-(3'-dimethylaminopropoxy)-cyclohep tane fumarate as an uncoupler and inhibitor of the respiratory chain].

Halidor 1-benzyl-1-(3'-dimethylaminopropoxy)-cycloheptane fumarate, activates succinate oxidation in mitochondria and inhibits reverse electron transport from succinate to NAD+ in submitochondrial partides preparations at doses of 2-10(-5)--10(-3) M. At a dose of 5--7-10(-4) M halidor cause a swelling of mitochondria incubated in 0.1 M NH4NO3. At higher concentrations (10(-3)--10(-2) M) halidor practically completely inhibits NADH and succinate oxidase activity of mitochondria and submitochondrial particles. It is suggested that vasodilating effect of halidor is due to the uncoupling of oxidative phosphorylation, thus causing a deficiency of ATP for contracting function of blood vessel muscles.

Adenosine Triphosphate↗
PubMedDate not supplied

[Effects of different regimes of freezing and thawing on chemiluminescence of rat liver mitochondria].

The rate of Fe2+ activated lipid peroxidation was studied as affected by the different freezing-thawing regime. The level of peroxidation was judged by kinetics and superfeeble luminiscence intensity of mitochondria. It was shown that freezing up to -196 degrees C and subsequent thawing of the mitochondria suspended in a salty medium (KCl) results in an increase in the rate of lipid peroxidation. A more distinct response to the introduction of peroxidation activator (Fe2SO4) is observed in mitochondria, especially in the first 1-2 minutes after ion introduction - in the phase of "slow flash". Besides, there is an increase in the level of stationary luminescence (2-10, 12-22 min) of the frozen-thawed mitochondria in comparison with the control. Slow thawing of quickly or slowly frozen mitochondria results in a more considerable increase in the luminescence light sum, than in the case of rapid thawing. The least-luminescence intensity after freezing and thawing of mitochondria suspension was observed after the rapid freezing and rapid thawing. In case of slow thawing the rate of mitochondria freezing does not considerably affect the degree of chemiluminescence.

Animals↗
PubMedDate not supplied

[The effect of osmotic pressure on oligomycin-sensitive ATPase activity and the liberation of Mg2+ from liver mitochondria of rats of various ages].

The influence of osmotic pressure of the incubating medium (25-500 mM sucrose) on oligomycin--sensitive, 2,4-dinitrophenyl-stimulated ATP-ase-activity, Mg2+ release and swelling of the liver mitochondria in 1-, 3-, 12-, 24-months Wistar rats is, investigated to determine age changes of structurally functional state of mitochondria. An increase in the sucrose concentration in the medium from 150 to 500 mM causes almost equal and practically absolute inhibition of ATP-ase-activity in different-age groups of rats, regardless of the presence or absence of Mg2+ ions in the medium A fall of the sucrose concentration to 150-25 mM induces a decrease in mitochondria ATP-ase-activity in Mg2+ free medium in 12- and 24-months rats (to 30 and 22%, respectively). No changes are observed in 1- and 3-months animals. Differences in rates of exogenous NADH oxidation by mitochondria of 1- and 12-months rats as a reflection of inner membrane damage degree are not observed under these conditions. Relative changes in ATP-ase-activity in a Mg2+ free medium with sucrose concentration of 25 mM (compared with 150 mM) correlate (r = 0.82) with those of optical density of mitochondria, measured at light wave length of 520 nm. It is obvious that the liver mitochondria of young and old rats sufficiently differ in spontaneous swelling rate in the media with different osmotic pressure: mitochondria of 1-month rats swell much faster than those of old rats. Considerable age differences of osmotic dependence of Mg2+ output from mitochondria are observed. They depend also on peculiarities of spontaneous organelle swelling dynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

2,4-Dinitrophenol↗
PubMedDate not supplied

[Electrical activity of the hearts of Hypophthalmichtus molitrix fish during cooling and warming].

In cold-unadapted H. molitrix, studies have been made on the electrical activity of the heart during cooling from 28 to 0 degrees. Cooling of the fish results in the increase of the duration of all ECG components and the decrease in their amplitude. The spontaneous activity gradually disappears, first in sino-atrium zone, then in atrium-ventricular one. Sinus rhythm disappeared at the abdominal temperature 3 degrees. The decrease in the heart rate was followed by its complete block without any extrasystoles and fibrillation. Warming of the fish up to the initial temperature (28 degrees) resulted in the recovery of cardiac activity, first in the atrium-ventricular zone, then in sino-atrium one.

Animals↗