Age-related changes phospholipids of sterlet in liver and dorsal muscles.

Study of phospholipids changes peculiarities in the liver and dorsal muscles of sterlet (Acipenser ruthenus Linnaeus) may be important to determine the etiology and pathogenesis of fatty liver. We established that the content of total phospholipids in tissues of the liver and dorsal muscles of three-year-old sterlet was less than for two-year-old fish by 15% and 20% (P ≤ 0.01), respectively. The amount of phosphatidylcholine (P ≤ 0.05), phosphatidylethanolamine, phosphatidylserine (P ≤ 0.01), phosphatidylinositol (P ≤ 0.01) and cardiolipin in the liver of 3-year-old sterlet was lower than for the 2-year-old fish, while quantitative indices for lysophosphatidylcholine and sphingomyelin were slightly increased. Similarly, in the cells of the dorsal muscles, the amount of phospholipid components (except lysophosphatidylcholine) was decreased with age. A decrease in the amount of phosphatidylethanolamine and phosphatidylserine in the dorsal muscles of 3-year-old sterlet was significant. The major phospholipids respective distribution was stable, except for phosphatidylethanolamine and particularly sphingomyelin.

[The regulation of fatty acid metabolism and other lipid compounds in ruminant animals].

The review deals with peculiarities of molecular mechanisms of metabolism regulation of fatty acids and other lipid components in preruminant and ruminant animals (i.e. before and after formation of the functioning of the mixed microbial population in the rumen). A characteristic of possible biosynthesis regulation processes, transformation, transport, utilization and catabolism of fatty acids with different molecular masses and peculiarities and of triacylglycerols and other lipid substances in the liver compartments, skeletal and heart muscle cells has been shown. Peculiarities of intracellular changes in metabolism of fatty acids and apolipoprotein B in the liver of neonatal calves under development of alimentary enteropathology have been considered. Main factors in the mechanism of regulation of intracellular metabolism of fatty acids and lipid substances have been defined.

[Inhibition of carbohydrate metabilsm enzymes by pentachlorophenol in cells of pectinolytic bacteria from gastrointestinal tract of animals and effect of clinoptilolite adsorbents on this process].

Changes in functional activity of specific enzyme reactions in the cells of pectinolytic bacteria from the gastrointestinal tract of animals in vitro cultivated in the medium containing pectin or glucose were studied against a background of the low dose effect of the wide spread biocide pentachlorophenol alone as well as in combination with the natural sorbents clinoptilolites. Regardless of the absence of transketolase reaction in the cells of all studied strains, they metabolized highly the above substrates that are dissimilar in chemical structure and produced different products of their degradation. It has been shown that the high metabolic level in the cells is provided by the function of the unique enzymatic reaction catalyzed by 2-keto-3-desoxy-6-phosphogluconate aldolase (EC 4.1.2.14) that permits to use effectively the metabolic pathway of Entner-Doudoroff. Cells could also utilize the same substrates via the Embden-Meyerhof-Parnas pathway, therefore they possess the other key reaction that is catalyzed by fructosobiphosphate aldolase (EC 4.1.2.13). Even a low dose of PCP (20 microM) decreased sharply activity of the mentioned key enzymes and intermediates' production in the cells of the studied strains with the use of both substrates. However, presence of clinoptilolites in the medium reduced significantly the biocide inhibition effect. Furthermore, in the medium with glucose, protection of intracellular metabolism with the help of sorbents was registered more clearly than with pectin. This can evidence for more mobile and simpler possibilities of accelerated production of necessary intermediates from glucose that are capable to induce activation of the key enzymatic reactions in cells utilizing selectively the substrates (which are different in accessibility and other characteristics) under the toxic agent effect.

[Metabolism of rumen microbial populations formed on biosubstrates with different assimilation under the effect of pentachlorophenol]. / Metabolizm mikrobnykh populiatsii rubtsia, sformovanykh na biosubstratakh riznoï dostupnosti, za diï pentakhlorfenolu.

It has been established that metabolism of mixed microbial population formed on easy assimilated sources of energy and nitrogen (concentrate diet) progressed on higher level. There is increase of amilolytic activity, formation of lactate, ammonia, low molecular carbonic acids with predomination of propionate molar fraction. The increased resistance to effect of pentachlorophenol (PCP) is characteristic nature of the latter. The role of the most resistant synthrophic bacteria to PCP increases. The pure strains of Streptococcus bovis and Megasphaera elsdenii do not stop metabolism at 100 microM of PCP. Mixed population of microorganisms formed on hard accessible biosubstrates (cellulose) and Butyrivibrio fibrisolvens have the increased cellulosolytic activity and while the high sensibility even to low doses of PCP (10-40 microM) is observed. It has been supposed that mechanism of PCP effect is ambiguous for various species of microbial complex of rumen. It's effect strength on all main chains of metabolism (membrane transport, energetic exchange, protein biosynthesis, etc.) significantly depends on capacity of pool of metabolic intermediates formed as a result of definite program of biotechnology of nurture, but significantly decreases the harmful effect of biocides.

[Features of glutamate dehydrogenase in fetal and adult rumen tissue]. / Osoblyvosti hlutamatdehidrohenazy slyzovoï rubtsia ploda ta dorosloï zhuinoï tvaryny.

Glutamate dehydrogenase (GDH) from rumen mucosa of cow fetus, liver and two forms from mucosa (bacterial and tissue) of the adult animal were partly purified and characterized. The activity of the bacterial glutamate dehydrogenase was shown to depend on qualities of a biomass of microbes, adhered on surface of rumen mucosa. All enzymes from tissues (GDHTRF, TRC, TLC), revealed the hypersensibility to increase in the concentration medium of Zn2+, guanosine triphosphate (GTP), acting here in a role of negative modulators, and also adenosine monophosphate (AMP) and leucine, which acted as activators. However, in the same concentrations these effectors do not influence the activity of the bacterial glutamate dehydrogenase. And if all tissues enzymes are highly specific to coenzyme NADH, the bacterial ones almost in 3 times is more active at NADPH use.

[Tyrosine tRNA(Q*psiA) from bovine liver. Identification of its sites of interaction with homologous aminoacyl-trna synthetase using chemical modification]. / Tirozynov tRNK(Q*psiA) pechinky byka. Vyznachennia dilianok ïï vzaémodiï z homolohichnoiu aminoatsyl-trnk-syntetazoiu metodom khimichnoï modyfikatsiï.

Interaction of the bovine liver tyrosine tRNA Q*psi A having short variable loop, with the homologous aminoacyl-tRNA synthetase has been studied by alkylation with ethylnitrosourea. It is shown that tyrosyl-tRNA synthetase (form M.r. 2x39000) protects 3'-phosphates of nucleotides 21 in D-loop, 31 and 44 in anticodon stem and 59-64 T psi C-stem of tRNA Tyr from alkylation. An anticodon of tRNA Tyr did not interact with this proteolytically modified form of tyrosyl-tRNA synthetase (M.r. 2x39000).

[Rumen bacterial metabolism as affected by extracellular redox potential]. / Metabolizm bakterii rubtsia za diï zovnishn'oklitynnoho redoks-potentsialu.

The redox potential (Eh) in the digestive tract of ruminants varies mostly within the ranges from -300 to +200 mV, in the rumen medium: from -130 to -200 mV. Eh and pH changes are of a linear character. Enhanced fermentation moves Eh towards negative values and improves growth of microorganisms. Eh values become even more negative as affected by Na2S, NaOH, cysteine and NaHSO3. Addition of picrate, sodium nitrate, hydrochloric acid, copper sulphate, gaseous oxygen and particularly heavy metals (silver and mercury) promotes positive Eh values and inhibits metabolism. Optimum Eh values for Megasphaera elsdenii are more negative, than those for Streptococcus bovis. In the process of S. bovis growth, the production of lactate, VFA, CH2O2 and NH3 increases, Eh and pH values decrease. More positive Eh values inhibit metabolism and growth rates of Selenomonas ruminantium, Bacteroides amylophilus, Bacteroides succinogenes and Streptococcus bovis to different degrees.

[Tissue metabolism in ruminants as affected by ionophores]. / Tkanynnyi metabolizm u zhyinykh za ionofornoï diï.

Remarkably influencing the VFA formation processes and their ratio in the rumen, ionophore action involves the range of free amino acids and individual enzymatic reactions of subcellular fractions of the rumen mucosa, heart muscle and longissimus muscle, kidneys and liver. The discovered reverse relationship between changes of levels of aminoacylation of tRNA and the amount of the respective free amino acids possibly is one of the crucial links in the common regulatory mechanism aimed at the maintenance of the specific stability of tissue and organ metabolism (including protein biosynthesis) in ruminants. It seems to be responsible for different effects of the ionophore on the investigated processes in different tissues and organs.

[Glutamine metabolism by rumen microorganisms: effect of monensin]. / Metabolizm hliutaminu mikroorhanizmami rubtsia: vplyv monenzynu.

Transformation of glutamine of mixed population of microorganisms-symbionts is demonstrated. Protection of glutamine and its intermediates (glutamate and pyroglutamate) under the influence of ionophore (monensin) is found. It is accompanied by the reduced (by 30-70 per cent and more) levels of ammonia formation, total VFA, acetate, butyrate, pH, alpha-ketoglutarate dehydrogenase and glutamine synthetase at parallel increase of L-aspartate and L-alanine: 2-oxoglutarate, aminotransferase activity, redox potential of stability of protein content. It is suggested that the rapid change of Eh level on the 24th hour of incubation reflects the main stage of pyroglutamate formation being one of the final products of glutamine degradation when monensin is used. Ionophore affects first of all the inhibition of metabolic processes in gram-positive rumen microorganisms.