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1.
Eur. j. anat ; 24(4): 257-261, jul. 2020.
Article in English | IBECS | ID: ibc-193956

ABSTRACT

The electromagnetic radiation from the mobile phone is a subject of recent study because of the enormous increase in mobile phone use through-out the world. The objective of this experiment was therefore to investigate the biochemical and histopathological effects of mobile phone radiation on male Swiss albino mice’s liver. Male mice were categorized into three groups in this research: control group (A), exposed group for 40 minutes (B) and exposed group for 60 minutes (C). Experimental groups were exposed to radiation per day for 60 days from 4G connected mobile phones. The control group received no radiation. At the end of the radiation exposure, biochemical (alanine transaminase (ALT) and aspartate transaminase (AST)) and histological tests were performed. The results indicated that there was significant (P < 0.05) increase in mean values of ALT and AST in both radiation-exposed groups of mice if com-pared to the control group. Histopathologically marked infiltration of mononuclear cellular aggregates were present surrounding the bile duct and hepatic artery in the liver of 60-minute-exposure group, whereas in 40-minute-exposure group con-gestion was observed in the portal vein and the central vein of the liver. The findings revealed and evidenced that mobile phone radiation has harmful effects on enzyme activity and liver tis


No disponible


Subject(s)
Animals , Male , Mice , Liver/radiation effects , Liver/pathology , Cell Phone , Electromagnetic Radiation , Radiation Exposure/adverse effects , Alanine Transaminase/radiation effects , Models, Animal , Alanine Transaminase/analysis , Aspartate Aminotransferases/radiation effects
2.
Res Vet Sci ; 125: 24-35, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31125819

ABSTRACT

It is well-known that gamma radiation initiates generation of free radicals which prompting serious cellular damages in biological systems. In the present study, we investigated the role of Ficus carica, a natural antioxidant substance, in modulating changes in liver and kidney functions, antioxidant enzyme's gene expression, and apoptosis, in male albino rats exposed to gamma radiation. A total of 40 rats were used in this experiment and divided equally into 4 groups: Group 1, rats administered distilled H2O (Control); Group 2, rats administered F. carica; Group 3, rats irradiated; and Group 4, rats treated with F. carica and irradiated. Groups 3 and 4 were exposed to whole-body gamma radiations at a dose level of 8 Gy and with a dose rate of 0.762 Gy/min. F. carica was administered to rats by gavage, for 3 consecutive weeks, before exposure to radiation. Five rats were sacrificed from each group at intervals of 24 and 72 h after cessation of treatment. The results revealed marked increases in alanine aminotransferase and aspartate aminotransferase levels in liver, a decrease in albumin level and increase in urea level in kidney. Irradiation resulted in cytotoxic effects as indicated by elevation in antioxidant enzyme's gene expression at 24 h, the opposite was observed at 72 h. Immunohistochemical analysis revealed that cytochrome c and p53 expressions significantly increased following exposure to radiation. Oral administration of F. carica pre-irradiation as a natural product plays a modulatory protective and anti-apoptotic role against cells damaged by free radicals induced by whole-body irradiation.


Subject(s)
Ficus , Gamma Rays/adverse effects , Kidney/radiation effects , Liver/radiation effects , Plant Extracts/therapeutic use , Alanine Transaminase/blood , Alanine Transaminase/drug effects , Alanine Transaminase/radiation effects , Animals , Antioxidants/pharmacology , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/drug effects , Aspartate Aminotransferases/radiation effects , Chemical and Drug Induced Liver Injury , Colorimetry/veterinary , Creatinine/blood , Creatinine/radiation effects , Immunohistochemistry/veterinary , Kidney/drug effects , Kidney/physiopathology , Liver/drug effects , Liver/physiopathology , Male , Plant Extracts/pharmacology , RNA/isolation & purification , Rats , Real-Time Polymerase Chain Reaction/veterinary , Serum Albumin/drug effects , Serum Albumin/radiation effects , Urea/blood
3.
Clin Chem Lab Med ; 41(7): 926-33, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12940520

ABSTRACT

The formation of superoxide partially accounts for the well-known oxygen enhancement of radiation-induced biochemical changes and cell damage. Radioprotective effects of copper (II), manganese (IV) or vanadium (IV) complexes, of superoxide dismutase-mimetic activity, on body weight, survival rate and some biochemical parameters in pre-treated irradiated, untreated irradiated and treated non-irradiated female albino rats have been studied 24 h after whole body gamma-irradiation at a dose level of 6 Gy. Survival time, body weight, red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin (Hb) concentration, percentage of hematocrit (Hct%), reduced glutathione (GSH), serum total protein, albumin, globulin (G), blood urea, creatinine and cholesterol were estimated, as well as the activities of blood superoxide dismutase (SOD), glutamate-oxaloacetic (GOT) and glutamate-pyruvic (GPT) transaminases, and alkaline phosphatase were assessed. A significant decline was shown in body weight, survival rate, the mean values of RBC and WBC counts, Hb and Hct percentages, and GSH concentration, as well as blood SOD activity, in whole body gamma-irradiated rats compared with the control non-irradiated rat group. The mean activity values of alkaline phosphatase, GOT and GPT, as well as the average values of blood urea, creatinine, total cholesterol, total protein and globulin were significantly elevated, while the average values of albumin and the albumin/globulin ratio were decreased in gamma-irradiated rats compared with the corresponding values of the normal control rat group. Pretreatment of rats with either manganese or vanadium complexes resulted in a significant increase in survival rate and body weight over that of the non-treated irradiated rat group. Pretreatment of rats with copper (II), manganese (IV) or vanadium (IV) complexes caused a significant increase in RBC and WBC counts, Hb concentration, HCt (%), GSH content and SOD activity in blood when compared to the irradiated rat group without treatment. The administration of copper (II), manganese (IV) or vanadium (IV) complexes prior to irradiation exposure resulted in a significant decrease in GOT and GPT activities in addition to blood urea, creatinine, cholesterol, globulin and total protein contents, while each complex exhibited a significant increase in plasma alkaline phosphatase, albumin, and the albumin/globulin ratio compared to the untreated irradiated rat group. Administration of vanadium (IV), manganese (IV) or copper (II) complexes in non-irradiated rats caused a significant increase in SOD activity without changing other biochemical parameters compared with the corresponding values of the normal control rat group. We conclude that these metallo-elements, particularly manganese (IV) and vanadium (IV) complexes of 2-methylaminopyridine, have radiation protection and radiation recovery. Furthermore, these metal complexes offer a new approach to overcome the pathological effects of ionizing radiation and suggest their use as a physiological approach to preventing or perhaps predominantly facilitating recovery from radiation injury.


Subject(s)
Gamma Rays , Metals/metabolism , Alanine Transaminase/blood , Alanine Transaminase/radiation effects , Alkaline Phosphatase/blood , Alkaline Phosphatase/radiation effects , Animals , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/radiation effects , Blood Proteins/radiation effects , Body Weight/radiation effects , Erythrocyte Count , Glutathione/blood , Hemoglobins/metabolism , Hemoglobins/radiation effects , Leukocyte Count , Rats , Superoxide Dismutase/blood , Superoxide Dismutase/radiation effects
4.
Radiats Biol Radioecol ; 41(1): 59-61, 2001.
Article in Russian | MEDLINE | ID: mdl-11253702

ABSTRACT

Pulse-modulated microwaves (frequency 2375 MHz, intensity: 2 microW/cm2 and 8 microW/cm2, pulse modulation from 50 to 390 Hz with step of 20 Hz; exposure time 5 min) changed the activity of aspartataminotranspherase of the donor blood. Aspartataminotranspherase activity was strongly dependent both on modulation frequency and microwave intensity. Maximum activity was found at 390 Hz and 8 microW/cm2. Maximum observed activity was about six times greater than control level of activity.


Subject(s)
Aspartate Aminotransferases/blood , Aspartate Aminotransferases/radiation effects , Microwaves , Humans
5.
Pharmacol Res ; 43(2): 185-91, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11243721

ABSTRACT

Pharmacological and cytogenetic evaluations of the protective effects of polyethoxylated castor oil cremophor-EL (cremophor) against hepato, renal and bone marrow toxicity induced by gamma irradiation in normal rats were carried out. A single dose of irradiation (6 Gy) caused hepatic and renal damage manifested biochemically as an elevation in levels of serum alanine and aspartate aminotransferase as well as an increase in blood urea. Cremophor administration at a dose level of 50 microl kg-1 intravenously 1 day before exposure to irradiation (6 Gy) protected the liver and kidney as indicated by the recovery of levels of hepatic aminotransferase, urea and lipid profiles to normal values. Gamma irradiation of male rats caused a decrease in reduced glutathione and an increase in the oxidized form in rat-liver homogenate. A highly significant increase in the incidence of micronucleated normochromatic erythrocytes and micronucleated polychromatic erythrocytes was observed after irradiation exposure. The induced genotoxicity in the bone marrow cells was corrected by pretreatment with cremophor. The findings of this study suggest that cremophor pretreatment can potentially be used clinically to prevent irradiation-induced hepato, renal and bone marrow toxicity without interference with its cytotoxic activity.


Subject(s)
Gamma Rays , Glycerol/pharmacology , Hyperlipidemias/blood , Kidney/drug effects , Liver/drug effects , Surface-Active Agents/pharmacology , Alanine Transaminase/blood , Alanine Transaminase/drug effects , Alanine Transaminase/radiation effects , Animals , Aspartate Aminotransferases/blood , Aspartate Aminotransferases/drug effects , Aspartate Aminotransferases/radiation effects , Bone Marrow Cells/drug effects , Bone Marrow Cells/radiation effects , Cholesterol/blood , Cholesterol/radiation effects , Creatinine/blood , Creatinine/radiation effects , Gamma Rays/adverse effects , Glutathione/drug effects , Glutathione/metabolism , Glutathione/radiation effects , Glycerol/analogs & derivatives , Glycerol/therapeutic use , Hyperlipidemias/drug therapy , Kidney/metabolism , Kidney/radiation effects , Liver/metabolism , Liver/radiation effects , Male , Mice , Micronuclei, Chromosome-Defective/drug effects , Micronuclei, Chromosome-Defective/metabolism , Micronuclei, Chromosome-Defective/radiation effects , Rats , Rats, Wistar , Surface-Active Agents/therapeutic use , Triglycerides/blood , Triglycerides/radiation effects , Tumor Cells, Cultured , Urea/blood , Urea/radiation effects
6.
Radiats Biol Radioecol ; 38(3): 405-10, 1998.
Article in Russian | MEDLINE | ID: mdl-9682735

ABSTRACT

The activity of aspartate aminotransferase, glutamate dehydrogenase in the liver of rats in 1, 7 and 15 days after gamma irradiation effect of the dose of 0.5 Gy on the background of consumption by animals of sodium nitrate, sodium nitrite and nitrosodiethylamine was studied. The combined influence of chemical agents and gamma irradiation modified the effects of nitro compounds-xenobiotics on processes of the synthesis and dissociation of the glutamic acid as well as the intensity of transamination of the reamination by aspartate aminotransferase.


Subject(s)
Aspartate Aminotransferases/drug effects , Aspartate Aminotransferases/radiation effects , Glutamate Dehydrogenase/drug effects , Glutamate Dehydrogenase/radiation effects , Glutamic Acid/metabolism , Glutamic Acid/radiation effects , Nitro Compounds/pharmacology , Amination/drug effects , Amination/radiation effects , Analysis of Variance , Animals , Aspartate Aminotransferases/metabolism , Deamination/drug effects , Deamination/radiation effects , Gamma Rays , Glutamate Dehydrogenase/metabolism , Liver/drug effects , Liver/enzymology , Liver/radiation effects , Male , Rats , Time Factors
7.
Ukr Biokhim Zh (1978) ; 66(1): 54-61, 1994.
Article in Russian | MEDLINE | ID: mdl-7974839

ABSTRACT

Wistar rats were exposed to 10, 20 and 40 sGy of gamma-irradiation. Maximal activity of 2-oxoglutarate- and succinate dehydrogenases, as well as of aspartate-2-oxoglutarate and pyruvate-2-oxoglutarate in the brain tissue was measured within 30 days after the exposure. Dehydrogenase activity was measured in the brain cortex, limbic system and in the cerebellum; transaminase activity was determined in the brain cortex, diencephalic zone and in the hypophysis. It was found that small doses of irradiation resulted in an oscillating increase of dehydrogenase activity with a decrease of the amplitude by the 30th day of the experiment. As the dose of irradiation increases, the periods of normal activity change into phases of inhibition of dehydrogenase action, the period of oscillations diminishes. Transaminase activity, as a rule, changes in a phase in a reversible manner as compared with dehydrogenase activity. These observations are discussed from the point of view of structural relations between these two systems in the intramitochondrial supramolecular structures, the so-called metabolons.


Subject(s)
Alanine Transaminase/radiation effects , Aspartate Aminotransferases/radiation effects , Brain/radiation effects , Ketoglutarate Dehydrogenase Complex/radiation effects , Succinate Dehydrogenase/radiation effects , Animals , Brain/enzymology , Citric Acid Cycle/radiation effects , Dose-Response Relationship, Radiation , Gamma Rays , Male , Rats , Rats, Wistar
8.
Acta cir. bras ; 8(2): 80-2, abr.-jun. 1993. tab
Article in English | LILACS | ID: lil-127431

ABSTRACT

O objetivo do presente estudo foi determinar as alteraçöes enzimáticas em ratos submetidos a hepatectomia parcial (HP) mais radiaçäo hélio laser. Ratos Wistar machos foram estudados 24, 48 e 72 horas após HP. Os animais foram divididos em 3 grupos: animais submetidos a 70// de HP; animais submetidos a 70// de HP mais aplicaçäo de hélio laser; animais submetidos a cirurgia simulada (CS). Alanina aminotransferase (ALT) e aspartato aminotransferase (AST) estavam aumentadas somente 24 horas após 70// da HP mais radiaçöes laser quando comparados com os de 70// HP e CS. Logo, a radiaçäo hélio laser acelera a regeneraçäo hepatocitária em grandes alteraçöes da funçäo hepática com base dos níveis séricos de ALT e AST


Subject(s)
Animals , Male , Rats , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Hepatectomy , Lasers , Alanine Transaminase/radiation effects , Aspartate Aminotransferases/radiation effects , Helium , Rats, Wistar , Liver Regeneration/radiation effects , Dose-Response Relationship, Radiation
10.
Mol Chem Neuropathol ; 15(2): 185-91, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1776992

ABSTRACT

In order to gain insight into the metabolic modifications induced in rat brain tissues by helium-neon (He-Ne) laser irradiation, in the research described here, we investigated the variations in the activity of the enzymes aspartate transferase (AST, EC 2.6.1.4), both cytosolic and mitochondrial, glutamate dehydrogenase (GIDH, EC 1.4.1.3), and total superoxide dismutase (SOD, EC 1.15.1.1), in the brain of rats treated with a very small dose (1.08 J) of He-Ne laser radiation. The rats were sacrificed 4 h after the treatment. The enzymes were evaluated spectrophotometrically in brain extracts of irradiated animals and also in untreated rats (controls) and rats that underwent simulated treatment (stressed). The data obtained from 5-10 animals assayed individually showed that, in the in toto brain tissues of the irradiated rats compared to the stressed rats, there was a marked increase of total SOD, together with an appreciable decrease of cytosolic AST, and insignificant variations in mitochondrial AST and GIDH. Stress alone caused a considerable decrease of total SOD and small but statistically significant increases of s-AST, m-AST, and GIDH.


Subject(s)
Aspartate Aminotransferases/radiation effects , Brain/radiation effects , Glutamate Dehydrogenase/radiation effects , Lasers , Superoxide Dismutase/radiation effects , Animals , Aspartate Aminotransferases/metabolism , Brain/enzymology , Cytosol/enzymology , Glutamate Dehydrogenase/metabolism , Helium , Mitochondria/enzymology , Neon , Rats , Rats, Inbred Strains , Reference Values , Superoxide Dismutase/metabolism
11.
Cell Mol Biol ; 37(4): 385-90, 1991.
Article in English | MEDLINE | ID: mdl-1934013

ABSTRACT

Effect of ultraviolet and gamma radiations on the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LD) in Biomphalaria alexandrina snails, the specific intermediate host of schistosomiasis, was investigated. Changes in the electrophoretic pattern of LD in the species under study were also taken as a measured parameter and the effect of gamma-irradiation on the glutathione content in the haemolymph of the snails have been included.


Subject(s)
Alanine Transaminase/radiation effects , Aspartate Aminotransferases/radiation effects , Biomphalaria/radiation effects , L-Lactate Dehydrogenase/radiation effects , Alanine Transaminase/metabolism , Animals , Aspartate Aminotransferases/metabolism , Biomphalaria/enzymology , Electrophoresis , Gamma Rays , Glutathione/analysis , Hemolymph/chemistry , Hemolymph/enzymology , Isoenzymes , L-Lactate Dehydrogenase/metabolism , Ultraviolet Rays
13.
Med Pr ; 39(1): 8-14, 1988.
Article in Polish | MEDLINE | ID: mdl-3405087

ABSTRACT

The 50 Hz frequency electric field was applied to guinea pigs at different times of the day. The electric field effects upon the alanine and asparagine aminotransferase in supernatant, mitochondrial and nuclear fractions of guinea pig liver were observed. The highest increase in alanine aminotransferase activity was observed in the mitochondrial fraction, whereas asparagine transferase exhibited the highest activity increase in the supernatant fraction. Those changes may be indicative of adverse effects of electric field upon the liver cell metabolism.


Subject(s)
Alanine Transaminase/metabolism , Aspartate Aminotransferases/metabolism , Cell Nucleus/enzymology , Electromagnetic Fields , Electromagnetic Phenomena , Liver/enzymology , Alanine Transaminase/radiation effects , Animals , Aspartate Aminotransferases/radiation effects , Cell Nucleus/radiation effects , Enzyme Activation/radiation effects , Guinea Pigs , Mitochondria, Liver/enzymology , Mitochondria, Liver/radiation effects
15.
J Natl Cancer Inst ; 72(6): 1261-9, 1984 Jun.
Article in English | MEDLINE | ID: mdl-6587147

ABSTRACT

Clone A human colon adenocarcinoma cells were grown in three-dimensional artificial capillary culture (ACC) to determine responses of capillaries treated 3 weeks after tumor cell inoculation with a specific, easily quantifiable cytotoxic agent, ionizing radiation. The high-density growth of tumor cells in ACC can be considered to be an in vitro analogue of a solid tumor. Changes in extracapillary space (ECS) fluid concentrations of lactate dehydrogenase (LDH) and aspartate aminotransferase (GOT) and the utilization of glucose in circulating medium were monitored after a supralethal radiation dose (90 Gy) of X-rays. Immediately after irradiation, increased levels of LDH and GOT were found that reached maximum levels about four to five times those found in nonirradiated control capillaries at 10-13 days post irradiation and then declined. Patterns of enzyme production appeared to correlate with the numbers of nonviable tumor cells collected from the ECS of the artificial capillaries. In contrast, glucose utilization showed little correlation with either enzyme concentration or dead cell production. It was determined that, while capillaries grown and treated in this manner appear to respond in a dose-dependent manner to ionizing radiation (as indicated by changes in LDH and GOT levels), these particular end points are relatively insensitive and are not suitable for studies in which therapeutic levels of X-radiation might be given. In other studies, tumor cells were removed from unirradiated capillaries by trypsinization and used to obtain complete survival curves after graded doses of X-radiation. The dose-response curves obtained indicate that clone A colon tumor cells grown in ACC show a marked decrease in their ability to accumulate sublethal radiation injury as compared to responses of these cells growing exponentially in asynchronous monolayer cultures, to synchronized mid-G1 tumor cells, or to tumor cells in stationary growth phase. These data suggest that ACC is a potentially useful model to study the effects of cytotoxic agents on human tumor cells.


Subject(s)
Adenocarcinoma/radiotherapy , Colonic Neoplasms/radiotherapy , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Aspartate Aminotransferases/radiation effects , Cell Line , Cell Survival/radiation effects , Clone Cells/metabolism , Clone Cells/pathology , Clone Cells/radiation effects , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Culture Techniques/methods , DNA, Neoplasm/radiation effects , Dose-Response Relationship, Radiation , Glucose/radiation effects , Humans , L-Lactate Dehydrogenase/radiation effects
16.
Radiat Res ; 96(1): 152-9, 1983 Oct.
Article in English | MEDLINE | ID: mdl-6622647

ABSTRACT

Heat stable serum enzymes were studied in rats exposed to microwaves (2.45 GHz, 120 Hz amplitude modulated) 24 hr after a single 4-hr exposure or immediately after 3 and 10 exposures to 0.1 to 55 mW/cm2. In addition, stable colonic temperature at 41.5 degrees C for 30 min was maintained by microwave exposure in a group of five rats under barbiturate anesthesia. Alkaline phosphatase and lactic dehydrogenase did not increase as a result of microwave exposure. Increased serum glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) were noted in the 41.5 degrees C group 24 hr after exposure. A threshold body temperature for acute cellular injury after microwave exposure was demonstrated. The acute cellular injury could be in the liver. These mild elevations in the serum enzyme levels (mean +/- SE, GOT = 167 +/- 40 U/liter: GPT = 74 +/- 26 U/liter) indicated that the injuries were not accompanied by any significant sequelae in the rat. From this threshold and colonic temperature (41.5 degrees C for 30 min) in barbiturate-anesthetized, microwave-exposed rats, we derived a tentative threshold for the whole-body average absorption rate at 14 W/kg (70 mW/cm2 at 2.45 GHz for adult rats) for 4 hr. This tentative threshold is subject to changes by duration of exposure and by compounding variables influencing maintenance of body temperature.


Subject(s)
Alanine Transaminase/radiation effects , Alkaline Phosphatase/radiation effects , Aspartate Aminotransferases/radiation effects , L-Lactate Dehydrogenase/radiation effects , Microwaves/adverse effects , Alanine Transaminase/blood , Alkaline Phosphatase/blood , Animals , Aspartate Aminotransferases/blood , Body Temperature , Colon , Dose-Response Relationship, Radiation , L-Lactate Dehydrogenase/blood , Male , Rats , Rats, Inbred Strains , Time Factors
17.
Vopr Med Khim ; 27(4): 523-7, 1981.
Article in Russian | MEDLINE | ID: mdl-7293085

ABSTRACT

Liver of X-ray irradiated rats /a dose of 18.06.10(-2) Ci per kg of body mass/, deprived of the body homeostatic influences, exhibited increased functional activity within the first day after irradiation: intensity of transamination was increased in mitochondria and supernatant as well as output of glucose and urea was elevated. Sensitivity to substrate stimulation of transamination and gluconeogenesis reactions was decreased in the liver within 3 days after irradiation.


Subject(s)
Liver/radiation effects , Alanine Transaminase/radiation effects , Animals , Aspartate Aminotransferases/radiation effects , Gluconeogenesis/radiation effects , Liver/metabolism , Male , Mitochondria, Liver/radiation effects , Perfusion , Rats , Time Factors , Urea/radiation effects
18.
Ukr Biokhim Zh (1978) ; 51(1): 14-7, 1979.
Article in Russian | MEDLINE | ID: mdl-425131

ABSTRACT

The influence of electromagnetic waves of metrical and centimetrical range on the transaminoferases activity was studied in the liver and small intestine of 69 rats. The experiment shows that the activity of aspartate and alanine aminotransferases is dependent on the power and duration of the action. It is established that the action of both the short-wave 160 mA diathermy and 30 MW/cm2 microwaves for 20 min is accompanied by inhibition of the liver and small intestine aminotransferases activity. The 20 min action of 12 MW/cm2 microwaves induces an increase in the aminotransferases activity of the liver, small intestine and serum.


Subject(s)
Alanine Transaminase/radiation effects , Aspartate Aminotransferases/radiation effects , Intestine, Small/radiation effects , Liver/radiation effects , Microwaves , Animals , Diathermy , Dose-Response Relationship, Radiation , Electromagnetic Fields , Intestine, Small/enzymology , Liver/enzymology , Male , Rats
19.
Biokhimiia ; 43(10): 1929-32, 1978 Oct.
Article in Russian | MEDLINE | ID: mdl-568950

ABSTRACT

Photooxidation of a histidine residue in aspartate transaminase leads to proportionate loss of the enzyme activity in reactions with L-aspartate and L-phenylalanine. Modification of two arginine residues by 1,2-cyclohexanedione strongly inhibits transamination of aspartate but, in contrast, slightly increases the rate of phenylalanine transamination. A stimulatory effect of a number of aromatic and aliphatic monocarboxylate anions on the rate of alanine transamination in the active site was observed. Indolylbutyrate was the most effective compound among those tested. Indolylbutyrate and indolylacetate act as competitive inhibitors in the case of transamination of phenylalanine or aspartate. The results were interpreted as indicating the presence in the active center of transaminase of a hydrophobic subsite participating in the binding of aromatic aminoacids.


Subject(s)
Alanine/metabolism , Aspartate Aminotransferases/metabolism , Phenylalanine/metabolism , Animals , Aspartate Aminotransferases/radiation effects , Binding Sites , Carboxylic Acids , Chemical Phenomena , Chemistry , Chickens , Cyclohexanones , Kinetics , Light , Substrate Specificity
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