RESUMEN
Activity of the glutathione antioxidant system has been studied in patients with drug-induced hepatitis treated with standart base therapy and combined with epifamin therapy. In blood serum of patients before treatment the decrease of reduced glutathione (GSH) level and the increase of glutathione peroxidase (GP) and glutathione reductase (GR) activities versus control were observed. Combined treatment with epifamin changed GSH level to the normal values. Treatment with epifamin was accompanied by pronounced increase in GP and GR activities compared with standard therapy. Activities of the NADPH-generated enzymes, glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase, which decreased at this pathology, also demonstrated a more significant increase than standart treatment.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Glutatión/sangre , Péptidos/uso terapéutico , Adulto , Anciano , Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Femenino , Glucosafosfato Deshidrogenasa/sangre , Glutatión/metabolismo , Glutatión Peroxidasa/sangre , Glutatión Reductasa/sangre , Humanos , Isocitrato Deshidrogenasa/sangre , Masculino , Persona de Mediana Edad , NADP/metabolismoRESUMEN
Activity of NADP-dependent isocitrate dehydrogenase (EC 1.1.1.42) increases and the catalytic characteristics of the enzyme isolated from the liver of rats are changed under conditions of apoptosis induction in comparison with these characteristics in health. Injection of melatonin induced a trend to normalization of kinetic parameters of catalytic activity and of some regulatory characteristics of the enzyme.
Asunto(s)
Isocitrato Deshidrogenasa/metabolismo , Hígado/enzimología , Melatonina/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Animales , Apoptosis/efectos de los fármacos , Catálisis , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Dactinomicina/administración & dosificación , Dactinomicina/farmacología , Electroforesis , Inyecciones Intraperitoneales , Isocitrato Deshidrogenasa/aislamiento & purificación , Cinética , Ratas , EspectrofotometríaRESUMEN
The work purpose was research of degree of free-radical processes intensity and catalase activity in blood serum of patients with a thyreotoxicosis syndrome at traditional treatment and the combined therapy with epifamin. Patients (n=25) have been divided into 2 groups: the first group of patients--12 persons who are on traditional treatment (antithyreoid drugs, beta-adrenoblockers); the second group--13 persons, are padding to basic therapy received epifamin on 1 tablet (10 mg) 3 times a day 10-15 minutes prior to meal within 7 days. Patients with thyreotoxicosis syndrome had an intensification of free-radical oxidation that was traced at measurement of biochemiluminescence parameters in blood serum. At the combined therapy with epifamin less expressed intensity of free-radical processes, and also increasing of the general antioxidant activity of an organism that did not descend at traditional treatment was observed. At carrying out of standard therapy of thyreotoxicosis syndrome, including application of antithyreoid drugs and beta-adrenoblockers, catalase activity decreased, that unfavorable affected antioxidant potential of an organism. At the combined therapy with epifamin level of catalase activity, on the contrary, increased, that could influence positively on antioxidant protection of an organism.
Asunto(s)
Antioxidantes/metabolismo , Péptidos/uso terapéutico , Tirotoxicosis/tratamiento farmacológico , Antagonistas Adrenérgicos beta/uso terapéutico , Adulto , Anciano , Antitiroideos/uso terapéutico , Catalasa/sangre , Quimioterapia Combinada , Radicales Libres/sangre , Humanos , Persona de Mediana Edad , Tirotoxicosis/metabolismoRESUMEN
Development of apoptosis is accompanied by a decrease in transcripts of NADP-isocitrate dehydrogenase (NADP-IDH, E.C. 1.1.1.42.), and also alterations of catalytic properties from the rat liver enzyme in comparison with control. Administration of thioctic acid is increased the level of expression towards normal values. Enzyme preparations NADP-IDH were obtained from rat liver at norm conditions, after introduction of tumor necrosis factor and thioctic acid action under apoptosis. Molecular weight of homogenous preparations of NADP-IDH purified from livers of control and experimental rats was 112 +/- 5.8 kDa, however Km values and pH-optimum changed in apoptosis. Regulation of NADP-IDH activity under effect of some intermediates of the tricarboxylic acid cycle also differed in these groups.
Asunto(s)
Isocitrato Deshidrogenasa/metabolismo , Hígado/efectos de los fármacos , Ácido Tióctico/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Animales , Apoptosis , Hígado/enzimología , Hígado/patología , Masculino , RatasRESUMEN
Electrophoretically homogeneous glutathione peroxidase (EC 1.11.1.9) preparation from rat liver with a specific activity of 1.46 U/mg of protein and a yield of 7.2% was obtained using the purification procedure developed. The K(M) values for reduced glutathione and hydrogen peroxide were 0.033 and 0.208 mM, respectively. The enzymatic reaction had the following characteristics: the temperature optimum, 32 degrees C; the pH optimum, 7.4; and the activation energy, 29.1 kJ/mol. The molecular weight of the enzyme was 88 kDa.
Asunto(s)
Glutatión Peroxidasa/química , Glutatión Peroxidasa/aislamiento & purificación , Glutatión/química , Peróxido de Hidrógeno/química , Hígado/enzimología , Animales , Catálisis , Calor , Concentración de Iones de Hidrógeno , Masculino , RatasRESUMEN
Experimental thyrotoxicosis in rats is accompanied by the increase of serum alanine aminotransferase (AlA), aspartate aminotransferase (AsA), creatine kinase-MB (CK-MB) activities and content of primary products of lipid peroxidation--conjugated dienes--in liver, heart and blood. This suggests impairments in these organs accompanying free radical processes intensification. Administration of melatonin decreased AlA, AsA and CK-MB activities and CD level decreased. Thyrotoxicosis increased catalase activity in liver, heart and blood. Exogenous melatonin decreased specific activity ofcatalase in blood and in heart in comparison with animals subjected to hyperthyroidism. However, some increase of catalase specific activity (approximately 15%) was observed in liver. alpha-Tocopherol content, raising in rat tissues in thyrotoxicosis development conditions, decreased after melatonin treatment. Thus, exogenous melatonin is capable to reduce lipid peroxidation intensity at thyrotoxicosis and to act as an adoptogen, regulating free radical homeostasis.
Asunto(s)
Antioxidantes/farmacología , Radicales Libres/sangre , Homeostasis/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Melatonina/farmacología , Tirotoxicosis/sangre , Animales , Catalasa/sangre , Hipertiroidismo/sangre , Hipertiroidismo/enzimología , Hígado/enzimología , Masculino , Miocardio/enzimología , Ratas , Tirotoxicosis/tratamiento farmacológico , Tirotoxicosis/enzimología , Tocoferoles/metabolismo , Transferasas/sangreRESUMEN
Biochemiluminiscense parameters (light sum and maximum flash) show that free radical oxidation intensity (increased in serum blood of rats with toxic hepatitis) is decreased upon the treatment with melatonin. At the same time, the tg a2 value (reflecting the total antioxidant activity) changes toward the normal level, which indicated a decrease in the degree of antioxidant system mobilization. Superoxide dismutase and catalase activities (increased in the liver and blood serum of rats with toxic hepatitis) also showed the tendency to decrease upon the melatonin administration. Evidently, melatonin can act as a factor correcting the oxidative stress caused by the toxic damage of liver.
Asunto(s)
Antioxidantes/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Hígado/efectos de los fármacos , Melatonina/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Catalasa/antagonistas & inhibidores , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Radicales Libres/antagonistas & inhibidores , Hígado/enzimología , Masculino , Oxidación-Reducción/efectos de los fármacos , Ratas , Ratas Endogámicas , Superóxido Dismutasa/antagonistas & inhibidoresRESUMEN
Biochemiluminescence increased, while aconitate hydratase activity and citrate accumulation in tissues of the liver and heart and blood decreased in rats with experimental hyperthyroidism. These changes reflect activation of free radical oxidation, damage to enzyme molecules with reactive oxygen species, and impaired utilization of citrate under pathological conditions. Melatonin treatment during hyperthyroidism normalized aconitate hydratase activity and citrate concentration. Biochemiluminescence study showed that the effect of melatonin is related to antioxidant activity of this hormone, inhibition of free radical oxidation, and suppression of reactive oxygen species generation.
Asunto(s)
Ácido Cítrico/metabolismo , Hipertiroidismo/tratamiento farmacológico , Hipertiroidismo/metabolismo , Melatonina/farmacología , Aconitato Hidratasa/metabolismo , Animales , Antioxidantes/farmacología , Ácido Cítrico/sangre , Hipertiroidismo/sangre , Hígado/metabolismo , Luminiscencia , Masculino , Miocardio/metabolismo , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , RatasRESUMEN
Intracellular distribution of aspartate aminotransferase (AAT) in Spirodela polyrhiza (Lemnaceae), strain SJ, has been studied by differential centrifugation. The bulk of the enzyme (73% of total cellular content) was localized in the cytoplasm and 24% activity was localized in chloroplasts. Purified cytoplasmic and chloroplastic isozymes differed by their affinity for substrates. The reaction balance was shifted towards direct and reverse transamination in the cytoplasm and chloroplast, respectively. Competitive inhibition of AAT by excessive substrates and enzyme affinity modulation by certain intermediates of the tricarboxylic acid cycle (isocitrate, succinate, and citrate) were observed. Possible involvement of AAT isozymes in the coordination of carbon and nitrogen metabolism through the regulation of 2-oxoglutarate synthesis and utilization in different cellular compartments is discussed.
Asunto(s)
Araceae/enzimología , Aspartato Aminotransferasas/metabolismo , Aspartato Aminotransferasas/química , Aspartato Aminotransferasas/aislamiento & purificación , Catálisis , Cloroplastos/enzimología , Ácido Cítrico/química , Citoplasma/enzimología , Isocitratos/química , Isoenzimas/química , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismo , Especificidad por Sustrato , Ácido Succínico/química , UltracentrifugaciónRESUMEN
Parameters of hepatic free radical oxidation and catalytic properties of NADP-isocitrate dehydrogenase (EC 1.1.1.42; NADP-IDH) have been investigated in normal rats and under conditions of toxic hepatitis. Development of hepatitis was accompanied by the increase of conjugated dienes, malondialdehyde and some chemiluminescence parameters. Toxic hepatitis was also accompanied by the increase of liver NADP-IDH. Homogenous preparations of liver NADP-IDH from normal and toxic rats exhibited different sensitivity to effectors studied (Fe2+, Ca2+, H2O2, reduced glutatione).
Asunto(s)
Intoxicación por Tetracloruro de Carbono/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Isocitrato Deshidrogenasa/metabolismo , Hígado/metabolismo , Animales , Intoxicación por Tetracloruro de Carbono/enzimología , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Activación Enzimática , Radicales Libres , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Cinética , Hígado/enzimología , Masculino , Oxidación-Reducción , RatasRESUMEN
Kinetic and regulatory properties of NADP-isocitrate dehydrogenase (NADP-IDH) and aspartate aminotransferase (AsAT) responsible for 2-oxoglutarate metabolism in the cytoplasm and mitochondria of rat liver were studied. Based on the subcellular location of these enzymes and their kinetic parameters (Km, Ksi) obtained with highly purified enzyme preparations, it is suggested that synthesis of 2-oxoglutarate should be mainly determined by cytoplasmic NADP-IDH (86% of the total activity in the cell), whereas its utilization should depend on cytoplasmic AsAT (78% of the total activity). AsAT from the rat liver was specified by substrate inhibition and also by changes in the enzyme affinity for the substrates under the influence of some intermediates of the tricarboxylic acid cycle: isocitrate, succinate, fumarate, and citrate. Key intermediates of nitrogen metabolism (glutamate, glutamine, and aspartate) are involved in the regulation of NADP-IDH and AsAT. These enzymes are regulated oppositely, and the catalytic activity of one enzyme can be stimulated concurrently with a decrease in the activity of the other. Obviously, carbon and nitrogen metabolism in the rat liver can be controlled through redistribution of 2-oxoglutarate between different metabolic processes via regulatory mechanisms influencing differently located forms of NADP-IDH and AsAT.
Asunto(s)
Aspartato Aminotransferasas/química , Isocitrato Deshidrogenasa/química , Ácidos Cetoglutáricos/metabolismo , Hígado/enzimología , Animales , Aspartato Aminotransferasas/metabolismo , Citoplasma/enzimología , Isocitrato Deshidrogenasa/metabolismo , Isoenzimas/química , Isoenzimas/metabolismo , Cinética , Hígado/metabolismo , Masculino , Mitocondrias Hepáticas/enzimología , RatasRESUMEN
Melatonin administered to intact animals increased glutathione concentration and activities of glutathione peroxidase, glutathione reductase, NADP-isocitrate dehydrogenase, and glucose-6-phosphate dehydrogenase in the liver. In animals with toxic hepatitis melatonin treatment decreased glutathione concentration and enzyme activities, which was probably associated with inhibition of free radical oxidation under the influence of this hormone.