Protein-nitrogen metabolism in the liver of rats intraperitoneally administered carminomycin]

It was found in the experiments with rats that in response to carminomycin administration in a single LD50 and the therapeutic doses during the treatment course the intracellular fond of the amino acids in the liver tissue increased, the autolytic processes activated, the activity of the transamination enzymes, histidine and ammonia lyases increased. The level of the residual nitrogen increased mainly at the expense of increased ammonia production and urea levels. These changes were more pronounced when the antibiotic was administered in LD50. Independent of the administration multiplicity and the antibiotic dosage they were of reversible nature and mainly disappeared by the end of the observation.     

Effect of carminomycin on the immunological reactivity of the body]

The morpho-functional state of the muscle lymphoid tissue of mice treated with karmionmycin (LD50, 1.1 mg/kg) was studied experimentally. Development of a number of changes evident of the cell disorganization in the lymphoid tissue was shown. The cytological shifts in the thymus and spleen were reversible, while the destructive period in the strumous gland was more prolonged. The morpho-structural normalization of the spleen did not coincide with reduction of its immunological function. The studies on the karminomycin effect on the kinetics of the primary immune response showed dependence of the antibiotic effect on the temporal ratio between the antigenic stimulus and the drug administration. The antibiotic had no effect on the inductive phase of the primary immune response but significantly suppressed its productive phase. On reproduction of the secondary immune response, a decrease in the content of the antibody-forming cells in the spleen was observed, production of the circulating antibodies remaining unchanged.     

Effect of dehydroepiandrosterone treatment on liver metabolism in rats

1. Administration of the 17-ketosteroid, dehydroepiandrosterone (DHEA), to rats results in lowered body weight. 2. A number of changes are seen in livers of treated rats. 3. These include higher liver weights and DNA, RNA and/or protein content, but lowered lipid and glycogen levels. 4. Activities of a number of liver enzymes involved in lipid and carbohydrate metabolism are altered by treatment. 5. In addition, net mitochondrial respiration is elevated by DHEA treatment. 6. Some of these findings may explain DHEA's antiobesity effect.     

Experimental effect of bruneomycin on the energy metabolism of liver tissue]

The effect of an antitumor antibiotic bruneomycin on the energy metabolism in the liver tissue was studied. Four hours after the drug administration the consumption of glycogen and glucose in the liver tissue increased because of glycogenolysis activation, which was evident from increased activity of prosphorylase, phosphofructokinase, hexokinase and summation glycolytic activity. 24 and 48 hours after the antibiotic administration the balance of consumption and resynthesis of phosphate macroergs in the liver tissue impaired, which was evident from decreased levels of ATP, impairement of conjugation of the processes of oxidation due to impairement of permeability and structural integrity of the mitochondrial membranes. Further decrease in the glycogen liver levels was mainly due to suppressed resynthesis of glycogen because of destructive-necrotic processes. Simultaneously the processes of glycolytic splitting of glucose decreased which was evident from decreased activity of the enzymes and summation glycolytic activity.     

Effect of etimizol on energy metabolism in rat brain]

Intraperitoneal injection of ethimizol in a dose of 25 mg/kg caused in intensification of the oxidative phosphorylion, an increase in creatine phosphate and a reduction of inorganic phosphorus concentration in the tissue of the rat brain. It is supposed that stimulation of the energy metabolism by ethimizol was caused by its activating effect on adenyylcyclase.     

Effect of furfural on the energy metabolism of fodder yeasts]

The effect of furfurol on the rate of oxygen uptake and carbon dioxide production by Candida tropicalis cells was studied. Furfurol was shown to inhibit significantly the yeast respiration, inducing aerobic glycolysis. Enhanced carbon dioxide production in the presence of furfurol was followed by an intensive degradation of trehalose and ethanol accumulation in the medium.     

Effect of triiodothyronine on aldolase metabolism in the liver of irradiated rats

The influence of different triiodothyronine doses on aldolase metabolism in rat liver was studied after whole-body X-irradiation. The effect of the hormone on the rates of synthesis and degradation and on the time of functioning of the enzyme in the exposed body was shown to vary markedly in the irradiated and intact animals.     

Evaluation of energy metabolism on the myocardium analyzing of creatine kinase isoenzymes in rats]

The purpose of this study is to evaluate the efficiency of energy metabolism in the myocardium by means of the activities of creatine kinase (CK) and CK isoenzyme following age-related change in the heart and experimental heart failure. Wistar strain male rats aged from 3 weeks to 57 weeks after birth were used. The main experimental results obtained are as follows. (1) There were differences in the compositions of CK isoenzyme of the ventricular, atrial, and papillar muscles. No apparent variation, however, was noted among the basal portions of the left and right ventricular muscles, free wall of the left ventricle, and apex. (2) Compositions of CK isoenzyme analyzed from the ventricle and atrium were clearly different. The level of CK-B subunit activity of the ventricular muscle was highest level in the 5-week-old rat, and subsequently dropped significantly in the 24-week-old rat. Thereafter, the level gradually increased with aging. Dramatic change in the energy metabolism in the myocardium occurred in rats more than 3 weeks old. (3) Decrease in activity of m-CK but increase in activity of succinate dehydrogenase analyzed from the ventricular muscle of experimental heart failure induced by monocrotaline was recognized. From these results, the author assumed that the trend of the composition of CK isoenzyme is one of the indices in the determination of the regulation of energy metabolism of the myocardium.     

Effect of corticosterone treatment on energy metabolism in rat liver mitochondria.

1. Effect of in vivo treatment (40 mg/kg body wt) with corticosterone on energy metabolism in rat liver mitochondria was examined under acute and chronic conditions in 20-, 35- and 60-day-old rats. 2. Acute treatment did not affect body or liver weight. However, chronic treatment caused increased liver weight in the former two age groups; in the 60-day-old animals the liver weight decreased. 3. Acute treatment resulted in a generalized decrease in state 3 respiration rates and state 4 respiration rates without having any significant effect on ADP/O ratios with glutamate, succinate and ascorbate + TMPD as substrates. However, rates of ATP synthesis decreased significantly. The effect was age-dependent, older animals showed increased resistance. 4. Chronic treatment resulted in uncoupling of oxidative phosphorylation without having significant effects on respiration rates. Once again, the effects were age-dependent. Consequently, the ATP synthesis rates were significantly lowered. However, it was apparent that the underlying mechanisms were entirely different. 5. With succinate as the substrate the state 3 respiration rates increased with age to reach adult values by day 60. The coupling efficiency was also exhibited via maturational changes.     

Effect of exercise on energy substrates metabolism in tissues of adrenalectomized rats

Effect of adrenalectomy and exercise on skeletal muscle, heart and liver glycogen and triglycerides, blood glucose and plasma free fatty acid level has been studied in the rat. It has been found that exercise-induced mobilization of glycogen in vastus deepest and soleus was diminished whereas utilization of liver glycogen was accelerated in adrenalectomized rats as compared to sham-operated controls. Triglyceride content in vastus deepest was reduced and in the liver increased in control rats but remained stable during exercise in adrenalectomized rats. In the latter group hypoglycemia occurred earlier and was more pronounced, whereas plasma free fatty acid level was markedly lower than in the control group.     

Effect of thyroid hormones and diacylglycerols on sphingomyelin metabolism in liver cell nuclei in rats of various ages]

Sphingomyelin metabolism in liver cell nuclei of rats of various age has been studied. It was found that the level of sphingomyelin hydrolysis in cell nuclei is the highest in young animals, showing a decrease in 24-month-old animals. The age-specific fluctuations in the activity of phospholipase C may be one of possible reasons for sphingomyelinase activity changes in liver nuclei during ontogenesis. It has been shown that thyroid hormones and diacylglycerols control the sphingomyelinase activity in rat liver cells.     

Regulation of energy metabolism in liver

Energy metabolism in liver has to cope with the special tasks of this organ in intermediary metabolism. Main ATP-generating processes in the liver cell are the respiratory chain and glycolysis, whereas main ATP-consuming processes are gluconeogenesis, urea synthesis, protein synthesis, ATPases and mitochondrial proton leak. Mitochondrial respiratory chain in the intact liver cell is subject to control mainly by substrate (hydrogen donors, ADP, oxygen) transport and supply and proton leak/slip. Whereas hormonal control is mainly on substrate supply to mitochondria, proton leak/slip is supposed to play an important role in the modulation of the efficiency of oxidative phosphorylation.     

Effect of hind limb muscle unloading on liver metabolism of rats

In response to decreased use, skeletal muscle undergoes an adaptive reductive remodeling. There is a shift in fiber types from slow twitch to fast twitch fiber types. Associated with muscle unloading is an increased reliance on carbohydrate metabolism for energy. The hind limb suspended (HLS) rat model was used as the experimental model to determine whether skeletal muscle unloading had any impact on the liver. We used a combination of actual enzyme assays and microarray mRNA expression to address this question. The GenMAPP program was used to identify altered metabolic pathways. We found that the major changes in the liver with HLS were increases in the expression of genes involved in the generation of energy fuels for export, specifically gluconeogenesis and lipogenesis. The expression of mRNA was increased (P<0.05) for three of the four enzymes involved in the regulation of gluconeogenesis pathway (pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G-6-Pase). Actual assay of enzymatic activity, in micromol . min(-1) . mg protein(-1) showed G-6-Pase (0.14+0.01 vs 0.17+0.01 P<0.05), fructose 1,6, bisphophosphatase (0.048+0.002 vs 0.054+0.002, P<0.07), and PEPCK (0.031+0.002 vs 0.038+0.012 (P<0.05) to be increased. We conclude that 1) atrophied muscle is not the only tissue to be affected by HLS, as there is also a response by the liver; and 2) the major changes in liver substrate metabolism induced by HLS appear to be limited to glucose and triglyceride production. The increase in glycolytic capacity in disused muscle is paralleled by an increase in glucogenic capacity by the liver.     

Effect of aeration conditions on the biosynthesis of carminomycin by an actinomadura carminata culture]

The effect of the aeration rate on biosynthesis of carminomycin by Actinomadura carminata and biochemical changes in the fermentation broth on the use of 3 complex media of different composition was studied. The carminomycin-producing organism can grow and produce the antibiotic within the ranges of the aeration changes from 0.98 to 18.56 mgO2/1-min. A decrease in the maximum rate of oxygen dissolution up to 0.98 mgO2/1-min resulted in some decrease in the activity level. Intensive aeration, i.e. 18.56 mgO2/1-min induced suppression of the antibiotic production by 25 per cent.