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L V Kravchenko

Publications and source records attributed to L V Kravchenko.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Effects of the degree of fish oil oxidation on the state of xenobiotic metabolism enzymes].

Wistar male rats received polysynthetic diets incorporating lard or fish of different oxidation degree as the sourse of fat. The feeding lasted 4 weeks. In the liver of rats on fish oil diet the activity of the enzymes of xenobiotic metabolism phase I (monooxigenase system, epoxide hydrolase, carboxyl esterase) and phase II (native and activated UDP-glucuronosyl transferase, glutathione transferase) located both in microsoma membranes and in cytozole was higher than in the animals on lard diet. The enzyme activity was much more enhanced in the use of oxidated fish oil. No effect of fish oil on serum and lysosome enzyme activity and rat hepatic structure was found.

Animals↗
PubMed1994

[Grain contamination by deoxynivalenol in Russia].

Deoxynivalenol (DON) contamination of fresh harvested grain (570 samples of wheat and barley harvested in 1990-1992) and food grain crops (468 samples of wheat, rye, barley from different regions of the Russian Federation) was examined for frequency and degree. DON was detected in 70% of the fresh harvested wheat, exceeding MPC in 26% of the samples and in 67% of the stored barley samples, exceeding MTL in 14%. In 1992 100% of the harvested wheat from fusariosis natural habitat were contaminated exceeding MPC in 92%. Out of 314 samples of food wheat, 29% contained DON in quantities exceeding MTL in 14%. 11% of food barley and 8% of food rye samples contained DON within MTL. Maximum quantities of contaminated wheat were produced in the North-Caucasian regions (66% of the contaminated samples) or were imported (21%). Contaminated wheat was used most frequently in the North-Caucasian region and Central regions (56% and 30% of the contaminated samples, respectively).

Edible Grain↗
PubMed1989

[Determination of epoxide hydrolase activity by high performance liquid chromatography].

A new highly sensitive method of microsomal epoxide hydrolase activity has been worked out. The product of styrene oxide enzyme hydrolysis--phenylethyleneglycol (PEG) was extracted by n-butanol, and its aliquot was analysed by high-performance liquid-chromatography on Silica Gel using hexane-isopropanol-water (80:28:2) mobile phase. PEG was detected at 210 nm. The detection limit of PEG was 5 pmol per injection. The coefficient of variation of the method was 3.7%.

Animals↗
PubMed1986

Biochemical changes in subacute mycotoxicosis induced by T-2 toxin in rats.

The intragastric administration to male Wistar rats of T-2 toxin at 1-1.3 mg/kg body weight for 7 days caused a sharp decrease in the liver activity of lysosomal enzymes: beta-galactosidase, beta-N-acetylglucosaminidase, alpha-mannosidase, cathepsins A, B, C and D and in the activity of enzymes of the 1st phase of metabolism of xenobiotics--aniline hydroxylase and carboxylesterase, as well as in the cytochrome P-450 level. At the same time, the subacute toxic effect of T-2 toxin was manifested in a significant increase in the activity of epoxide hydrolase and an enzyme of the 2nd phase of metabolism of xenobiotics--UDP-glucuronosyltransferase. A possible mechanism of the observed enzymological changes is discussed.

Animals↗
PubMed1986

[The enzymes of the metabolism of exogenous compounds in the comparative assessment of the toxicity of trichothecene mycotoxins].

Moderate clinical, biochemical and hematologic signs of intoxication were observed in mice after single administration of HT-2 toxin (deacetylated derivative of T-2 toxin) in LD50 of 12.75 mg/kg or in 1/5 of LD50 for 7 days. The toxin produced no toxic effect when 1/10 and 1/50 of LD50 were administered for 14 days. With the dose exceeding 1/50 of LD50 a reduction in cytochrome P-450 content, carboxylesterase activity and increased activity of UDP-glucuronosyltransferase and glutathione transferase were recorded. T-2 toxin produced a more pronounced toxic effect, inhibited UDP-glucuronosyltransferase and insignificantly stimulated glutathione transferase activity. Lower HT-2 toxin toxicity is believed to depend on its ability to activate conjugation reactions to a greater extent than T-2 toxin.

Animals↗
PubMed1986

[Hepatocyte ultrastructure in mice with chronic T-2 mycotoxicosis].

Trichothecene mycotoxin (T-2 toxin) was administered by gastric intubation to CBAXC57BL/6 mice at a dose of 0.33-0.45 mg/kg for 6 months. No symptoms of intoxication were observed, however, electron microscopic studies revealed a severe damage of hepatocyte structure, especially of smooth and rough endoplasmic reticulum. Besides the destruction of hepatocytes an increase in the number of primary and secondary lysosomes was observed. Regenerating foci were found in the majority of liver cells. In chronic T-2 mycotoxicosis there is a strong correlation between the damage of hepatocyte ultrastructure and the changes in organella-specific enzymatic activity in the liver, that was described previously.

Animals↗
PubMed1984

[Effect of vitamin A excess and T-2 toxin on the enzyme system activities of the second phase of xenobiotic metabolism in the rat liver].

Oral administration of retinyl palmitate to young Wistar rats during 7 days (70,000 IU of vitamin A per 100 g of body weight daily) caused a decrease in the liver UDP-glucuronosyl transferase and glutathione transferase activities and a significant decrease in the liver glutathione-SH content. A single administration of T-2 toxin (3 mg per kg of body weight) to rats after the treatment with high doses of vitamin A was accompanied by an increase in T-2 toxicity. The rat mortality was doubled and the decrease in UDP-glucuronosyl transferase and glutathione transferase activities was more distinct as compared with the rats treated with T-2 toxin only. Vitamin A excess appears to decrease the phase II drug-metabolizing enzyme activities and glutathione-SH content in rat liver tissue. Excess of vitamin A may be responsible for an increase of T-2 toxicity in rats.

Animals↗
PubMed1983

[Effect of T-2 toxin on organ ultrastructure and organelle-specific enzyme activity in rats].

The time-course of the ultrastructural changes and activities of 6 marker enzymes of subcellular particles (succinate dehydrogenase, beta-glucosidase, beta-N-acetylglucosaminidase, acid RNAse, glucose-6-phosphatase and 5'-nucleotidase) has been studied in the liver, spleen and thymus in rats administered T-2 toxin (mycotoxin produced by some Fusarium species). A pronounced difference in the effect of T-2 toxin on the organs has been found. In the liver, the toxin induced a destruction of rough endoplasmic reticulum membranes, reduced ribosome number and progressively decreased activities of most enzymes. In the spleen, early and significant ultrastructural disturbances of all the cell membrane components and simultaneous lysosomal activation were observed. The changes in the thymus were characterized by a fast development of cell hydratation, organelle swelling and necrosis of some thymocytes with parallel increase in repair processes, infiltration by phagocytes and a selective activation of lysosomal hydrolases in the end of experimental time (72 h.). The results obtained emphasize an importance of cellular and subcellular membrane alterations in the mechanism of T-2 toxin action.

Acute Disease↗