[Effect of quercetin on some indicators of the proteinase-proteinase inhibitor system in rats upon administration of cobalt chloride to them]

The results of quercetin effect on some changes of proteinase--proteinase inhibitor system parameters in rats under cobalt chloride injection are shown. It was established that preliminary quercetin administration prevened neutral proteinase activation and alpha-2-macroglobulin activity decreasing after 2 h of cobalt chloride influence.

[Effect of pentoxyphylline on certain indicators of the proteinase-proteinase inhibitor system in rats upon administration of cycloheximide]

The pentoxifylline influence on neutral proteinase, alpha-2-macroglobulin, trypsin-alpha-1-proteinase inhibitor and elastaseinhibitory activity under cycloheximide injection has been investigated. Two hours after cycloheximide injection the activity of neutral proteinases increases in rats serum, lungs, heart, liver and kidneys. The preliminary injection of pentoxifylline prevents increase of neutral proteinases activity. Cycloheximide also decreases alpha-2-macroglobulin activity in serum and liver and trypsin-, elastaseinhibitory activity of alpha-1-proteinase inhibitor in all investigated organs. At using pentoxifylline the alpha-2-macroglobulin activity doesn't change in liver and increases in serum in comparison with only cycloheximide and there are no observed any alpha-1 inhibitor proteinase activity changes in rats serum and organs.

[Effect of actinomycin D and cycloheximide on lipoproteins in blood serum and liver cytosol of rats under oxidative stress]

The influence of protein synthesis inhibitors on rat lipoprotein content and composition under oxidative stress caused by cobalt chloride injection has been investigated in the present work. It has been concluded that apoprotein synthesis is very important process influencing on adaptive reactions under free-radical oxidation activation conditions. Co-administration of cobalt chloride and actinomycin D or cycloheximide (the inhibitors of the protein synthesis) has realy prevented hyperlipoproteinemia in many cases but hasn't influenced on lipoprotein oxidation. Pre-beta- and beta-lipoproteins were discussed to have mRNA pool in hepatocytes.

[Heme metabolism and oxidative stress]

The role of heme metabolism in oxidative stress development and defense reactions formation in mammals under different stress factors are discussed in the article. Heme metabolism is considered as the totality of synthesis, degradation, transport and exchange processes of exogenous heme and heme liberated from erythrocyte hemoglobin under erythrocyte aging and hemolysis. The literature data presented display normal heme metabolism including mammals heme-binding proteins and intracellular free heme pool and heme metabolism alterations under oxidative stress development. The main attention is focused to the prooxidant action of heme, the interaction of heme transport and lipid exchange, and to the heme metabolism key enzymes (delta-aminolevulinate synthase and heme oxygenase), serum heme-binding protein hemopexin and intracellular heme-binding proteins participating in metabolism adaptation under the action of factors, which cause oxidative stress.

Regulation of heme oxygenase activity in rat liver during oxidative stress induced by cobalt chloride and mercury chloride

Activities of heme oxygenase and tryptophan-2,3-dioxygenase and cytochrome P450 content in liver as well as absorption of the Soret band and optical density at 280 nm in serum were determined 2 and 24 h after administration of HgCl(2) and CoCl(2) and after co-administration of the metal salts with alpha-tocopherol. Administration of HgCl(2) and CoCl(2) increased the contents of hemolysis products in the serum, induced heme oxygenase, and decreased cytochrome P450 content in the liver. Injection of HgCl(2) increased the activity of tryptophan-2,3-dioxygenase holoenzyme and enzyme saturation with the heme, but administration of CoCl(2) decreased these parameters. Pretreatment with alpha-tocopherol completely blocked the changes induced by HgCl(2) after 24 h. Induction of heme oxygenase induced by CoCl(2) was not blocked by alpha-tocopherol, but this antioxidant normalized the increase in the level of hemolysis products in the serum and decrease in tryptophan-2,3-dioxygenase holoenzyme activity and cytochrome P450 content. Mechanisms of regulation of heme oxygenase by mercury and cobalt ions are discussed.

[Research of the academician I. N. Bulankin on problems of protein chemistry]

The article presents an information about scientific researches on the problem of chemical properties and structure of proteins, which were carried out intensively by the biochemists of Kharkiv State University in 30-50 years of XX cent., headed by I. N. Bulankin, academician of Ukrainian Academy of Sciences. This researches dealt with the processes of proteolysis and protein denaturation, the peculiarities of globular and fibrilliar proteins behavior in solution, the properties of complexes with proteins and nucleic acids, etc. The historic analysis of origin and development of this scientific problem at the biochemistry chair of the university and its gradual replacement by researches with other biochemical problems has been carried out. The data concerned with the general situation in the field protein structure of estimation at the world and home biochemistry are cited too. In connection with the above presented the authors give the grounded conclusions about the importance of the scientific researches carried out by I. N. Bulankin as well as about.

[Foundation and development of biochemistry at the Imperial Kharkov University]

The article summarizes the biochemical researches carried out at Kharkiv Imperial University from the middle of XIX century up to the cessation of its existence in 1920 as a result of transformation into the Kharkiv Institute of National Education. Scientific activity at the Chair of Medical Chemistry at Medical Department is described in details. Information on professors who led the chair and their researches are represented. Among them a great attention is spared to the Kharkiv works of such famous scientists as A. Danilevsky and V. Gulevich, who made a great contribution to the development of Russian and world biochemistry. There are also some resordes about researches of biological and physiological chemistry carried out at other chairs of Medical Department and Department of Physics and Mathematics of the Kharkiv University. In particular, the article presents the works of well-known plant physiologists and biochemists prof. V. Palladin and V. Zalessky, and the endocrinological researches led by prof. A. Reprev.

[Proteinase-proteinase inhibitor complex in rats under oxidative stress caused by administration of cobalt chloride]

Mechanisms of proteinase-inhibitor proteinase system response was estimated following of cobalt chloride injection. The increase proteinase activity, which led to significant decrease of alpha-2-macroglobulin (alpha-2-MG) level was established that indicated to the removal of the proteinase in complex with alpha-2-MG from the organism. Increase of alpha-1-proteinase inhibitor (alpha-1-PI) trypsin-inhibitory activity in the kidneys testify about removal of oxidative alpha-1-PI.

[Metabolism of heme and hemoproteins in rat liver upon administration of mercuric chloride]

Rat liver delta-aminolevulinate synthase (delta-ALAS) activity in the early period after mercury chloride administration (0.7 mg per 100 g body weight) was found to be followed by free heme level increase, which was registered by the increase of heme saturation of the heme-binding protein tryptophan-2,3-dioxygenase (T-2,3-DO). delta-ALAS and heme oxygenase activity increase was observed 24 h after action. Microsomal cytochromes P450 and b5 levels decrease. Heme saturation of the T-2,3-DO returned to control level. Heme oxygenase and T-2,3-DO induction promoted hepatocytes free heme level normalization. Heme oxygenase and delta-ALAS induction role in the liver cells defense from the oxidative damage is discussed.

Regulation of delta-aminolevulinate synthase activity during the development of oxidative stress

Activities of rat liver delta-aminolevulinate synthetase (delta-ALAS), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH), GSH content in the liver, and the absorption spectrum of blood serum were investigated after CoCl2, HgCl2, or beta-adrenoblocker (propranolol) injection and after CoCl2 and propranolol co-administration. Inhibition of the activity of the key heme biosynthesis enzyme delta-ALAS was most pronounced and prolonged during the first hours after CoCl2 and CoCl2 plus propranolol injections; this was associated with accumulation of Co2+--protoporphyrin-containing products of hemolysis. Inhibition of delta-ALAS after propranolol injection is not mediated by hemolysis. A decrease in GSH content precedes the induction of heme biosynthesis only in the case of HgCl2 administration, and this was associated with inhibition of GR and G6PDH. The decreased GSH content during the first hours after injection of propranolol and co-administration of CoCl2 and propranolol was not followed by increase in delta-ALAS activity 24 h after the injection. The mechanisms of the increase in the free heme content in the liver during the early stages of oxidative stress and the regulation of the key heme biosynthesis enzyme are discussed.

[Content and composition of lipoproteins of rat blood and liver and various parameters of oxidative stress during administration of cobalt chloride]

Cobalt chloride effect on rat liver and serum blood lipoproteins content and composition and on some characteristics of lipid peroxidation and oxidative stress was investigated. The activation of free-radical oxidation and oxidative stress development were judged from the dynamics of lipid peroxidation products accumulation, from cathepsin D unsedimental activity and from the alteration of microsomal cytochrome P-450 content and from activity of a number antioxidative enzymes. In order to evaluate the state of glutathione-defence system the activities of glutathione peroxidase, glutathione S-transferase, glutathione reductase and some NADPH-generating enzymes and reduced glutathione level alteration were studied in liver. The data obtained show that the cobalt chloride injection leads to the development of the oxidative stress and to activation of some antioxidant defence system, namely, glutathione-depending enzymes, and of microsomal cytochrome P-450 catabolism. The system blood lipoproteins (liver lipoproteins was found to participate in metabolism adaptation under oxidative stress and in maintenance of biological membranes structure and functioning.

Effect of cobalt chloride on content of lipids and lipoproteins in serum and liver of rats

Lipids and the composition of lipoproteins in blood serum and liver cytosol, total lipid, and phospholipid contents in liver subcellular fractions and the spectrum of microsomal liver lipids were studied in male Wistar rats after a single injection of cobalt chloride. Virtually all lipid and lipoprotein fractions in blood and liver were increased and lipoprotein composition was changes. The lipid composition of liver microsomes did not change under these conditions. Thus, microsomal membranes are stable under developing oxidative stress.

[Some characteristics of metabolism in osteoarticular, cardiovascular, and liver tissues in "experimental osteochondrosis"]

Considerable changes of collagen, glycosaminoglycans and calcium were observed both in vertebral tissues, bone, and in the heart, vessels, liver during development of "experimental osteochondrosis". The results have shown, that desintegration of biochemical processes in different tissues may be one of the factors affecting several diseases in one organism.

[Effect of adrenal stress on activity of proteinase and alpha-1-proteinase inhibitor in rats]

The effect of adrenal stress on the proteinase and alpha-1-proteinase inhibitor activities in blood serum and cytosols of the rat organs were investigated. The reliable change was marked only in the alpha-1-PI level research of lung tissue cytosol. The proteolysis suppression was revealed in the heart and kidney tissue, while the proteolysis activation was revealed in serum and less in the lung tissue cytosol. Changes in proteinase level in the myocardium and kidney tissue play the primary role in respect to those of the other research liquids under study.

[Dynamics of RNA synthesis and transport into the intact and regenerating rat liver in the presence of sublethal doses of actinomycin D]

The time-dependent characteristic of RNA synthesis has been studied against the effect of sublethal doses of actinomycine D in cells with different proliferative activity, connection of synthesized RNA with RNP-particles of nuclei and its transport into the ribosomes and cytoplasmic postribosomal fraction. Against a background of actinomycine D sublethal doses (150 and 300 micrograms per 100 g body weight) from 0.5 to 4% of RNA is synthesized in comparison with the original level. The level of specific radioactivity of RNA depends on the original functional state of the liver. The newly synthesized RNA is found in the nuclei RNP-particles and transported into the cytoplasm. It is localized in ribosomes (2-3% in intact and about 6% in regenerating liver from the original level) and in the postribosomal fraction (8-10% and 16-18% in intact and regenerating liver, respectively. It is supposed that RNA synthesized against the effect of sublethal doses of actinomycine D takes part in conservation and restoration of realization of genetic information system activity, that is observed 12 hours after the antibiotic injection.

[Activity of cytoplasmic NADP-dependent dehydrogenase in rat liver during induction of cytochrome P-450 by phenobarbital]

Activity of oxidation enzymes of the pentosephosphate way (glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44), cytoplasmic malate dehydrogenase (decarboxylating oxaloacetate) (NADP+) (EC 1.1.1.40) and isocitrate dehydrogenase (NADP+) (EC 1.1.1.42) as well as the content of microsomal cytochromes b5 and P-450 in the rat liver have been studied 24 hours after 1, 2, 3, 4 and 5 intraperitoneal administrations of phenobarbital (4 mg per 100 g of the body weight). It is shown that the cytochrome P-450 content increases after a single administration of phenobarbital and then it gradually grows reaching its maximum after 4 administrations and falls after 5 administrations (though it remains high as compared to the control animals). The content of cytochrome b5 increases only after 4 administrations of phenobarbital and after 5th one it returns to the initial level. The content of microsomal gangliosides calculated per 1 mg of microsomal protein decreases after a single administration of phenobarbital and 5 days later it returns to the initial level. Activity of glucose-6-phosphate dehydrogenase increases after a single administration of phenobarbital, that of malate dehydrogenase--after 3 administrations, 6--phosphogluconate-dehydrogenase--after 4 administrations of the preparation. The 5 administrations of phenobarbital makes activity of all the mentioned dehydrogenases return to the initial level. Activity of isocitrate dehydrogenase under given conditions of the experiment does not change.

The effect of inhibitors of transcription and translation on basal and haem-induced tryptophan-2,3-dioxygenase activity in the rat liver

The effect of actinomycin D and cycloheximide on basal tryptophan-2,3-dioxygenase (EC 1.13.11.11) activity in Wistar rat liver and on the enzyme activity induced by pretreatment with haemin was studied. Inhibition of either transcription or translation was accompanied by a reduction in tryptophan oxygenase activity, and this occurred more rapidly in the case of inhibition of translation. A 40% and 45% reduction in holoenzyme activity was found 2.5 and 6.5 h after introduction of cycloheximide and actinomycin D, respectively. Pretreatment with the antibiotics did not impair saturation of the apoenzyme by exogenous haem but haem induced tryptophan oxygenase activity was affected in various ways. Introduction of cycloheximide after haemin was accompanied by a rapid fall in the activity of both forms of the enzyme, but when transcription was inhibited under these conditions there was a subsequent increase in both holoenzyme activity and overall tryptophan oxygenase activity. The results support the concept that a regulatory pool of haem exists in hepatocytes and that haem is involved in both the activation and the degradation of tryptophan oxygenase.

[The role of heme in the regulation of tryptophan-2,3-dioxygenase activity and content of cytochrome P-450 in rat liver]

The effects of exogenous heme on the activity of delta-aminolevulinate synthase, heme oxygenase, tryptophan-2.3-dioxygenase and microsomal cytochrome content in rat liver were studied. It was shown that hemin chloride diminishes the delta-aminolevulinate synthase activity and provokes heme oxygenase induction. This is paralleled with the induction of the tryptophan 2.3-dioxygenase apoenzyme and an increase in the saturation of the enzyme with heme. The cytochrome b5 content does not change thereby, whereas that of cytochrome P-450 shows a decrease. Upon combined administration of actinomycin D and hemin the cytochrome P-450 level is markedly increased. Actinomycin D by itself has no effect on the hemoprotein concentration. It is concluded that the increase in the cytochrome P-450 level results from the activation of heme-induced mRNA translation.

[Activity of key enzymes of heme metabolism and the content of several hemoproteins in the liver of rats of various ages]

The activity of key enzymes of heme metabolism (delta-aminolevulinate synthase, EC 2.3.1.37, and heme oxygenase, EC 1.14.99.3) and the content of some hemoproteins were examined in the liver of male Wistar rats aged 1, 3 and 24 months. It is established that the activity of delta-aminolevulinate synthase decreases when rats reach the age of 3 months and remains at the same level in rats aged 24 months. The content of microsomal cytochrome P450 and the activity of tryptophan-2,3-dioxygenase holoenzyme increase when rats reach the age of 3 months. The total tryptophan-2,3 dioxygenase activity is higher in animals aged 24 months as compared to those aged 1 month. The heme oxygenase activity and the content of microsomal cytochrome b5 do not change with age.

[Effect of cobalt chloride on the activity of key enzymes of heme metabolism in the rat liver]

The effects of actinomycin D and cycloheximide on the original and CoCl2-induced delta-aminolevulinate-synthase and heme-oxygenase activities in rat liver were investigated. It was shown that 1.5 hours after CoCl2 administration the delta-aminolevulinate-synthase activity diminishes, then increases up to the original level within the subsequent 4.5 hours, showing a further increase thereafter. The heme-oxygenase activity does not change within 1,5 hours and is then increased. Actinomycin D and cycloheximide suppress the increase in the CoCl2-induced heme-oxygenase activity, whereas that of the delta-aminolevulinate-synthase activity is blocked only by cycloheximide. Hence, the increase in the CoCl2-induced delta-aminolevulinate-synthase activity in the liver is a result of activation of translation. The degree of tryptophan pyrrolase saturation with heme decreases already by the 6th hour, whereas the level of heme in liver mitochondria and microsomes decreases only by the 15th hour following CoCl2 injection. The heme content in the liver shows a further decrease irrespective of the increase in the delta-aminolevulinate synthase activity induced by CoCl2. It may be concluded that under the given experimental conditions this enzyme is not a rate-limiting step in the terminal reaction of heme biosynthesis.

[Age-dependent characteristics of the regulation of cytoplasmic NADP+-dehydrogenases in the liver of rats on different diets]

It is established that the activity of malate dehydrogenase and glucose-6-phosphate dehydrogenase in rats aged 1,3 and 12 months lowers under fasting and on high-fatty diet and in old animals (24 months) on a high-fatty diet only the glucose-6-phosphate dehydrogenase activity decreases. When rats after fasting are put on high-carbohydrate diet the activity value of the mentioned enzymes has already returned to the initial level after 12 hours in rats aged 1 and 12 months and in rats aged 3 months it exceeds that activity in intact rats. The rise in the activity of the determined enzymes is completely blocked by the preliminary administration of actinomycin D. The isocitrate dehydrogenase activity remains unchanged under conditions of maintaining animals on different diets.

[Activity of nuclear RNA polymerases in the liver of rats of different ages after phenobarbital administration]

DNA-dependent RNA-polymerases of nuclei isolated from the liver of rats aged 3- and 24 months were studied in different periods after phenobarbital administration. It is shown that 4h after single intraperitoneal injection of the preparation (80 mg per 1 kg of the body mass) to young animals the activity of the RNA-polymerase I rises, it remains higher, the following 12-20 h and then returns to the initial level. The activity of RNA-polymerases II and III under these conditions 16 h later remains higher the following 8 h and 24 h later the activity of the first enzyme returns to the initial value and that of the second one becomes still more. In old rats (24 months) the activity of all three classes of RNA-polymerases is lower than in young ones and increases only 48 h later. Under long-term administration of phenobarbital (40 mg per 1 kg of the body mass daily, 4 days) the activity of RNA-polymerase I was the same as in the intact animals of the corresponding ages and the activity of RNA-polymerases II and III increased both in young and old rats. Single administration of the preparation increases the liver mass in the young animals 24 h later and in the old ones--48 h later. Long-term administration of the preparation enhances its mass both in young and old animals, but its relative increase is more expressed in rats at the age of 3 months.

[Enzymes of the antioxidant system of rat liver during aging]

It is shown that ageing induces in rats intensification of a GSH-dependent antioxidant effect of the liver cytozole, growth of glutathione-S-transferase activity of cytozole, microsomes and mitochondria, a decrease of the NADPH generation rate in cytozole with malate and glucose-6-phosphate oxidation (the rate remaining at high level with isocytrate oxidation). It is supposed that under definite physiological conditions a lowered rate of NADPH generation in the malate dehydrogenase and glucose-6-phosphate dehydrogenase reactions in old animals may limit the efficiency of the NADPH-GSH-dependent antioxidant system of the liver cells. The peroxidase activity of cytochrome P-450 of microsomes and the glutathione reductase activity (EC 1.6.4.2) of cytozole rise in the liver of rats up to their 12 months and fall considerably with ageing. Cytochrome P-450 in the membranes of endoplasmic reticulum plays the role of an antioxidant.

[Age variations in ethylmorphine demethylase and benzopyrene hydroxylase activities in rat liver microsomes]

The ethylmorphine demethylase activity of the rat liver microsomes was higher in three-month animals (as compared to one-month), remained at a high level in the 12-month and decreased in old rats. The benzopyrene hydrolase activity increased in three-month animals, decreased in 12-month rats and remained the same with subsequent ageing of the organism. Asynchronicity of variations in the oxidation rate of different xenobiotics with ageing is considered as a result of changes in substrate specificity of the monooxygenase system due to metabolic peculiarities which reflect the age development of the organism and extinction of the reproduction function.

[Interaction of the protein-synthesizing systems of the cytoplasm and mitochondria during hormonal induction of oligomycin-sensitive ATPase in the liver of rats of various ages]

The paper deals with the effect of thyroxine and insulin on the oligomycin-sensitive ATPase activity, the content of DNA and RNA in the liver mitochondria of uneven-aged rats as well as with the effect of actinomycin D and selective inhibitors of cytoplasmic and mitochondrial translation on the ATPase induction. The both hormones rise the mitochondria ATPase activity (whose increase is blocked by actinomycin D) and also the content of RNA in all mitochondrial fractions of young animals. In old animals insulin induces ATPase without changing the RNA level and thyroxine increases ATPase and RNA only in heavy mitochondria. The DNA content grows under the effect of thyroxine in heavy mitochondria of young animals and is not changed after the insulin administration. Under the effect of thyroxine both the cytoplasmic and the mitochondrial protein-synthesizing systems and mitochondria division are activated. Insulin affects ATPase mainly via cytoplasmic translation and to a lesser extent via mitochondria.