[Mechanism of the toxic action of the mycotoxin of Fusarium sporotrichiella].
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Animal Feed↗
Biomedical subjects
L V Kravchenko
Publications and source records attributed to L V Kravchenko.
[Use of an electrophoretic esterase fractionating method for a study of their compartmentalization].
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Animals↗
[Determination of lysosome membrane stability].
Effect of different concentration of non-ionic detergents (Triton X-100, Triton X-305, BRIJ-35 and Triton WR-1339) on total and non-sedimentable activity of 8 rat liver lysosome enzymes (acid phosphatase, acid DNase, acid RNase, arylsulphatases A and B, beta-glucuronidase, beta-galactosidase, beta-glucosidase and beta-acetylglucosaminidase) was studied. Only Triton X-100 at the concentration of 0.1% (and higher) was found to release completely lysosome enzymes. Low concentrations of Triton X-100 (0.025-0.05%) were used to characterize the strength of enzyme binding: the level of releasing acid DNase, beta-galactosidase, beta-glucuronidase and acid phsophatase being considerably higher than that of other lysosome enzymes studied. On the basis of the data obtained a method is worked out, which is suitable for series studies of the stability of lysosome membranes under different physiological and pathological conditions. The essence of the method is the treatment of membrane particles with increasing concentrations of Triton X-100 (0.025; 0.05 AND 0.1%) AND THE SUCCESSIVE ESTIMATION OF NON-Sedimentable activity of marker enzymes. The method detected troubles in the stability of rat liver lysosome membranes under starvation, protein deficiency and aging.
Animals↗
[Effect of ethanol on stability of cell membranes in experiments using isolated liver].
Effect of ethanol on functional activity of isolated perfused rat liver was studied (rate of O2 utilization, absorption of bromosulpholeine from perfusate, bile formation); total activity and activity in supernatant of nine marker enzymes were also determined (malate dehydrogenase, beta-glucuronidase, arylsulphatases A and B, beta-galactosidase, beta-glucosidase, acetylesterase, glucoso-6-phosphatase, alanine aminotransferase and aspartate aminotransferase). Activity of the enzymes was simultaneously studied in perfusate. Ethanol (0.5%) caused distinct impairement in functional activity of isolated liver; rate of bile formation and absorption of bromosulpholeine from perfusate were primarily altered. Degree of impairements in functional activity of liver tissue correlated with the concentration of ethanol in perfusate. In analysis of correlation between the total activity of the enzymes in liver tissue and their activity in supernatants and perfusate it was shown that the concentration (1%) of ethanol used did not produce damaye effect on plasma membranes and membranes of subcellular structures of hepatocytes, but, within certain limits, it displayed a stabilizing effect.
Animals↗
[Isolation and phenotypic characteristics of growth-stimulating rhizobacteria (PGPR), with high root-colonizing and phytopathogenic fungi inhibiting abilities].
Some bacterial strains isolated from the plant rhizosphere showed high root-colonizing ability and antiphytopathogenic activity against 6 fungal species. The antifungal activity was species-specific, which could be accounted for by the fact that the isolates differed in the ability to produce lytic enzymes (chitinases, proteases, and lipases) and to secrete cyanide. The possibility of using there rhizobacteria to control phytopathogens is discussed.
Fungi↗
[Tomato root exudates and their effect on the growth and antifungal activity of Pseudomonas strains].
The study of the effect of the root exometabolites of tomato plants on the growth and antifungal activity of the plant growth-promoting Pseudomonas strains showed that the antifungal activity of plant growth-promoting rhizobacteria in the plant rhizosphere may depend on the sugar and organic acid composition of root exudates.
Carboxylic Acids↗
[Xenobiotic-metabolizing enzymes in rat liver and small intestinal mucosa with varying combinations of polyunsaturated omega-6 and omega-3 fatty acids in the diet].
Male Wistar rats were fed for 30 days semi-synthetic diets containing lard, corn oil or fish oil (ichthynic oil from herring muscles), differing in total content of saturated and polyunsaturated fatty acids (PUFA), in the ratio omega 6/omega 3 PUFA and in content of vitamin E. The activity of xenobiotic metabolizing enzymes was similar in liver of rats fed diets with lard or corn oil, while activities of epoxide hydrolase and UDP-glucuronosyltransferase were significantly higher if fish oil was used. The type of fat affected also the benzyl-produced induction of the enzymes. Differences in the enzyme activities observed did not depend on content of vitamin E in dietary fats. Unlike liver tissue, activities of microsomal enzymes were not considerably altered in rat small intestine in various experimental groups. The microsomal lipids of liver tissue and small intestine mucosal membrane were similar in the total content of saturated and unsaturated fatty acids in various animal groups but the level of omega 6 and omega 3 PUFA in the tissues depended on the ratio omega 6/omega 3 PUFA in diets.
7-Alkoxycoumarin O-Dealkylase↗
[The production of antifungal metabolites by Pseudomonas chlororaphis grown on different nutrient sources].
It was found that the antifungal activity of Pseudomonas chlororaphis SPB1217 is due to phenazine-1-carboxylic acid, phenazine-1-carboxamide, and two unidentified exometabolites. The carbon source used for the growth of this bacterial strain and iron ions present in the medium considerably influenced the proportion between the antifungal metabolites. The maximum production of phenazines was observed in the media enriched in amino acids and iron ions. The absence of correlation between the production of phenazines and antifungal activity indicates that phenazines are not the only antifungal metabolites of the strain. Organic acids as nutrient sources provide for more intense production of exometabolites and for a higher level of antifungal activity than do sugars.
Amino Acids↗
[The effect of tryptophan of plant root metabolites on the phyto stimulating activity of rhizobacteria ].
Aseptic tomato and radish roots were found to exude 2.8-5.3 and 290-390 ng tryptophan per seedling per day. The inoculation of radish plants with rhizosphere pseudomonads increased the root biomass by 1.4 times. The inoculation of tomato plants with the same pseudomonads was ineffective. The beneficial effect of bacterial inoculation on the radish plants can be explained by the fact that the introduced rhizobacteria produce the plant growth-stimulating hormone indole-3-acetic acid. In pot experiments, the addition of this phytohormone to the soil increased the mass of radish roots by 36%. The phytohormonal action of the rhizosphere microflora was found to be efficient provided that the concentration of tryptophan in the rhizosphere is sufficiently high.
Indoleacetic Acids↗
[Mathematic modeling of the dynamics of the interacting population of the rhizosphere microorganisms].
A quantitative model is proposed to describe the population dynamics of associative nitrogen-fixing microorganisms in the plant rhizosphere as dependent on the rate of carbon substrate exudation by plant roots. By changing the values of the basic model parameters, the effect of various factors on the behavior of two competing populations of rhizospheric microorganism can be studied.
Bacteria↗
[Dynamics of abundance of antifungal strains of Pseudomonas in the rhizosphere of hydroponic cucumbers grown on greenhouse mineral substrate].
Data were obtained on the dynamics of the abundance of the biocontrol strains of Pseudomonas chlororaphis SPB1217 and Pseudomonas fluorescens SPB2137 with antifungal activity. These strains are able to develop in the rhizosphere of cucumbers grown on mineral substrate under hydroponic conditions in industrial greenhouses. After four weeks of vegetation of plants, the abundance of the inoculated strains was 19-28% of the total bacterial numbers determined by inoculation onto solid medium. The investigated strains spread together with the young, actively growing and exudating roots; they reached a stable level of abundance in deep layers of the greenhouse substrate. A significant difference in the abundance of fungi in the tested variants was observed after 20 days of vegetation: the abundance of fungi in the control was two times higher than in the variant inoculated with strain SPB2137.
Antibiosis↗
[The effect of selenium on enzymes metabolizing xenobiotics in rat liver].
Activity of enzymes involved in metabolism of xenobiotics was not altered in liver tissue of rats kept on a ration enriched with selenium at a dose of 2.5 mg/kg. Both organic form of selenium (yeast meal, selenomethionine) and inorganic derivatives (sodium selenite) at a dose of 5 mg/kg of ration caused distinct activation of epoxide hydrolase, UDP-glucuronosyl transferase and glutathione transferase within 6 weeks after the experiment beginning, while content of cytochrome P-450, glutathione-SH and glutathione peroxidase activity were not significantly altered. Within 9 weeks the enzymatic activity remained at the higher rate only in rats kept on the ration with sodium selenite. Relationship between toxic effects of selenium high doses and alterations in activity of enzymes involved in metabolism of xenobiotics is discussed.
Animals↗
[Comparative study of the effectiveness of the classical and modified Cooper protocol for breast cancer chemotherapy].
Efficiency of routine and modified Cuper procedures was studied after evaluation in saliva and urine of women with mammary gland tumor of the following parametres: alterations in dynamics of acrolein excretion with saliva, dynamics of alterations in calculated therapeutic doses of cyclophosphane administered using these procedures, dynamics of the ratio between non-metabolized cyclophosphane and its initial level in urine of the patients. Analysis of the data obtained suggest that the liver tissue enzymatic systems, involving in biotransformation of cyclophosphane, were distinctly less impaired during the modified Cuper procedure as compared with the routine course, thus corroborating advantages of the modified procedure used in chemotherapy of patients with mammary gland tumor.
Antineoplastic Combined Chemotherapy Protocols↗
The effect of aspartame on the activity of rat liver xenobiotic-metabolizing enzymes.
Male, Wistar rats were administered aspartame (40 or 4000 mg/kg body weight) in their diet for 90 days. By 45 days, the activities of three microsomal enzymes, epoxide hydrolase, carboxylesterase, and p-nitrophenyl-UDP-glucuronosyltransferase, were significantly increased in rats consuming 4000 mg/kg of aspartame. By 90 days, however, the activity of the xenobiotic-metabolizing enzymes of the rats given aspartame did not differ significantly from the activity of control animals. From these results, we conclude that the consumption of aspartame does not substantially alter the function of the hepatic microsomal enzymes which protect the organism from foreign compounds found in its environment and food.
Animals↗
[Dietary protein as a modulator of the activity of enzymes metabolizing xenobiotics. UDP glucuronosyltransferase and glutathione transferase].
Activity of microsomal UDP-glucuronosyl transferase and cytosol glutathione transferase was studied in the liver and small intestine mucosa of rats which received rations with 5.18 and 33% of protein, during 2 months. Activity of UDP-glucuronosyl transferase GT1-isoform both in native and in detergent-activated microsomes of the liver increased with protein deficiency in the ration, while GT2-isoform activity and that of three glutathione transferase forms decreased. Excess of protein in the ration led to a growth of conjugation enzyme activity in the liver. The food protein level influenced the degree of GT1 and GT2 induction by benzyl but it did not change the capacity for induction of glutathione transferase. Activity of conjugation enzymes in the small intestine mucosa of rats to a lesser degree depended on the protein level in the ration.
Animals↗
[The effect of the trichothecene mycotoxin deoxynivalenol (vomitoxin) on calcium homeostasis, vitamin D metabolism and receptors in rats].
Metabolism of calcium and vitamin D was studied in young rats administered with trichothecene-related mycotoxin deoxynivalenol (vomitoxin) at a daily dose of 10 mg/kg perorally within 7 days. The vomitoxin treatment caused a moderate hypocalcemia, a decreased absorption of calcium in small intestine as well as led to decrease of alkaline phosphatase activity in blood and small intestine mucosal membrane. Density and saturation of bone tissue with minerals were not altered. Concentration of 25-OHD in blood and activity of vitamin D3(25)-hydroxylase in liver tissue were decreased by 40% and 30%, respectively. Development of 1,25(OH)2D3 and 24,25(OH)2D3 as well as concentration of total and free 1,25(OH)2D3 receptors were not altered in kidney. At the same time, these impairments of calcium and vitamin D metabolism were prevented by providing high content of vitamin D in the ration--0.25 mg/kg of food. Impairments in calcium metabolism caused by vomitoxin may be partially related to development of a secondary deficiency in vitamin D.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
[Protective effect of selenium in acute T-2 mycotoxicosis].
Male Wistar rats were fed diets supplemented with selenium (0.5 and 2.5 mg/kg) for 6 weeks. When T-2 toxin was administered at 3.8 mg/kg body weight; sings of intoxication were less distinct in rats fed selenium-supplemented diets. Mortality caused by T-2 toxin was two times lower if selenium content amounted to 2.5 mg/kg. The level of cytochrome P-450 and the rate of deethylation of 7-ethoxycoumarin were considerably decreased in the liver of rats that received T-2 toxin and fed a diet with high selenium content. At the same time the activity of epoxide hydrolase and UDP-glucuronosyltransferase was significantly higher (1.6 and 1.7 times more) as compared with unsupplemented group. The results obtained allow to assume that there is a relationship between the decrease of T-2 toxin toxicity and the change in its metabolism in rats fed selenium-supplemented diets.
Animals↗
[Calcium and vitamin D metabolism and enzymes of xenobiotic metabolism during chronic action of mycotoxins].
Experimental rats received T-2 toxin (0.063 mg/kg), deoxynivalenol (1.6 mg/kg) and aflatoxin B1 (0.008 mg/kg) during 6 months. Moderately manifest changes were detected in metabolic enzyme activity of foreign substances in the liver and small intestine mucosa. All mycotoxins induced weak hypocalcemia, while ionized calcium concentration in the blood serum decreased only after T-2 toxin administration that was attended by an increase of PTH level. Alkaline phosphatase activity and calcium transport in the small intestine were not significantly changed. Concentration of 25-OHD in the blood serum and 25-hydroxylase D3 activity in the liver decreased in rats given T-2 toxin. Formation of 1,25(OH)2D3 and 24,25(OH)2D3 in the kidneys was not significantly changed, while T-2 toxin inhibited regulatory changes in 1-hydroxylase 25-OHD3 activity in response to the action of PTH and adenylate cyclase activator forskolin. The results of the investigation have evidenced that calcium metabolism disorders during chronic action of mycotoxins could be partially associated with secondary vitamin D deficiency.
Animals↗