Role of sex dimorphism in the pharmacological action of etimizol

It has been shown that in female rats the level of ACTH, corticosterone in the blood, relative mass of adrenals, maintenance of T3, T4 in the serum and liver was significantly higher, but the activity of liver enzyme microsomes system was lower than in males; no sex differences were observed in myocardial creatine phosphokinase system. The influence of the etimizol on the female rats significantly speed up amidopyrine N-demethylation and biotransformation of hexobarbital. In males these systems react less on etimizol, but it reduces the speed of amidopyrine N-demethylation.     

Features of peroxidase oxidation of amidopyrine and its analogs]

Peroxidatic oxidation of N-alkyl and sulfalkyl-substituted 4-aminopyrazolones (amidopyrine and metapyrine) is mediated by oxyperoxidase, whereas the oxidation of non-substituted 4-aminoantipyrine occurs via the classical peroxidase cycle, without oxyperoxidase accumulation. The free radicals formed at the first step of the oxidation cycle show a tendency for disproportionation and exchange. During catalysis in heavy water the oxidation of substituted aminopyrazolones is accelerated by plant peroxidase. This effect is due to the activation of the second oxidative state of the enzyme. Complete peroxidatic oxidation of amidopyrine results in the formation of several reaction products. The main product is not identified as dioxypyramidone formed via nonenzymatic peroxidatic oxidation. The oxidation of the indicator (azopyram) which represents an amidopyrine-aniline mixture results first in the formation of amidopyrine radicals. The reaction product (dye) is formed via the binding of these radicals to aniline radicals. The latter are predominantly formed via a nonenzymatic route during the reduction of the amidopyrine radicals by aniline. Similar to the formation of azopyram and the full oxidation of amidopyrine, this reaction is accompanied by the displacement of the substituents from the 4-amino group.     

The effect of hypoxia and of subsequent baro-oxygenation on the function of the microsomal oxidation system in the rat liver]

The increase of cytochrome P-450 by 34% and its catalytic activity with substrate amidopyrine by 57% as compared with control has been shown under hypoxia (0.029 MPa, 1 h). Hyperoxia (0.2 MPa, 1 h) increases the metabolism of amidopyrine by 148%, benzo[a]pyrene by 158% and aniline by 114% and consecutive affection of hypoxia and hyperoxia--by 247, 45 and 138% correspondingly at fixed cytochrome P-450 amount in both series. The amount of diene conjugates and Schiff's bases under hypoxia increases by 40 and 69% correspondingly, the activity of SOD and catalase decreases by 25 and 23%. The activity of hyperoxia raises the diene conjugate content by 19% at all this SOD activity increases by 95%. Consecutive affection of hypoxia and hyperoxia increases the level of diene conjugates and Schiff's bases by 26 and 23% correspondingly, without changing SOD and catalase activity. The relative microsomal viscosity of lipid layer and zones of enzyme-lipid contacts decreased by 20 and 24% under hypoxia, but under hyperoxia and consecutive affection and hypoxia and hyperoxia it increases by 29-28% and 56-40% correspondingly.     

Liver cytochrome P-450 induction in rats by drug preparations and the body vitamin A allowance

The content of P-450 cytochrome and vitamin A was determined in the liver of mature male rats who received for a month daily parenteral administrations of phenobarbital solutions (Pb; 40 mg/kg), rheopyrine (a mixture of equal aliquots of amidopyrine and butadione; 200 mg/kg), amidopyrine (100 mg/kg) or water (control). The animals were kept on a semisynthetic diet, receiving once, every week 400 IU of retinol-palmitate per rat. Pb administration markedly (more than threefold) increased P-450 cytochrome content in the liver. Rheopyrine and amidopyrine also elevated its level, but to a lesser extent than Pb. Pb and rheopyrine also depressed vitamin A levels in the liver and caused either a trend towards its decrease (Pb) or a significant decrease (rheopyrine) of its overall content in the liver. The effect of amidopyrine on the concentration and storage of retinol in the liver was less pronounced. The data obtained suggest that the drugs inducing P-450 cytochrome are capable of disturbing vitamin A content in the body.     

Activity of NADPH-dependent monooxygenase hydroxylating system of rat liver under the effect of tetramethylthiuramdisulfide

Changes in the activity of a NADPH-dependent monooxygenase system of the rat liver are studied under the effect of tetramethylthiuramdisulphide. Under these conditions aniline hydroxylation is shown to be inhibited to a higher extent than amidopyrine demethylation. Besides a decrease in the level of cytochrome P-450, the central component of the microsomal system of hydroxylation, there appears cytochrome P-420--an inactivated form of cytochrome P-450.     

Peroxidase activity of mitochondrial cytochrome <Emphasis Type="Italic">c</Emphasis> oxidase

Mitochondrial cytochrome c oxidase is able to oxidize various aromatic compounds like o-dianisidine, benzidine and its derivatives (diaminobenzidine, etc.), p-phenylenediamine, as well as amidopyrine, melatonin, and some other pharmacologically and physiologically active substances via the peroxidase, but not the oxidase mechanism. Although specific peroxidase activity of cytochrome c oxidase is low compared with classical peroxidases, its activity may be of physiological or pathophysiological significance due to the presence of rather high concentrations of this enzyme in all tissues, as well as specific localization of the enzyme in the mitochondrial membrane favoring accumulation of hydrophobic aromatic substances.     

Effect of diet overloaded by fats on the enzyme systems of metabolism in rats

The feeding of rats with high-fat diet (a part of fats was 50% of energy value of ration against 20% in control) during 4 weeks increased the level of cytochrome P-450 in the liver and enhanced aniline- and p-nitrophenol hydroxylase activity of CYP2E1 as well as erythromycin N-demethylase activity of CYP3A; the activity of aldehyde dehydrogenase class 3, UDP-glucuronosyl transferase, glutathione-S-transferase and N-acetyl transferase. At the same time, the moderate decrease of indomethacin-O-demethylase of CYP2C both phenolsulfotransferase activity were fixed. The changes of enzymatic activity correlated with activating of processes of gluconeogenesis, glycogenolysis and, especially, ketogenesis. A high-fat diet enhanced reactions of biotransformation of amidopyrine, acetanilide, toluene, sulfadimezine, were catalyzed with CYP2E1, CYP3A and enzymes of conjugation, simultaneously it increased the hepatotoxicity of paracetamol.     

Modifying action of drug preparations on the effect of promutagen compounds

The Ames test has shown that the action of nitrosomorpholine and cyclophosphane promutagens on bacteria of Salmonella typhimurium TA 1950 increases while using S-9 liver fraction of rats treated with pharmaceuticals of amidopyrine, reserpine and pyrazidol and decreases while using those treated with phenazepam.     

The cytochrome P-450 content and catalytic activity in rat liver microsomes during hyperbaric oxygenation]

The effect of different conditions of hyperbaric oxygenation (HBO) on content and catalytic activity of cytochrome P-450 in rat liver cytochrome has been studied. The intensity of lipid peroxidation in microsomal membranes has been determined by the content of dien conjugates and Schiff's bases. The rate of amidopyrine demethylation has been shown not to change, but the rate of aniline hydroxylation decreases on 34, 57 and 64% under increase of oxygen pressure up to 0.3, 0.5 and 0.7 MPa correspondingly. The level of dien conjugates increase on 66-87% under all studied conditions of HBO. Cytochrome P-450 content decreases on 45% under the action of 0.7 MPa, but content of Schiff's bases increases on 210% as compared with control.     

Histochemical and cytologic changes in the liver in experimental poisoning and subsequent pregnancy]

In 275 white rats chronic intoxication was produced by injection of amidopyrine acetaldehyde and chloraldehyde derivatives for 4 months. Histochemical and electron microscopic investigations of the liver under the experimental conditions and subsequent pregnancy revealed certain changes in nucleic metabolism, glycogenolisis, in the content of sulfhydryl, disulfide, carboxylic groups of protein molecules. Decrease in activity of enzymes of Krebs cycle and pentosophosphate cycle proved the deep changes in hepatocytes at the level of oxidation-reduction processes and protein synthesis. Ultramicroscopic changes in the nucleus, in cytoplasmic network, mitochondria and local degenerative alterations determined the level of morphologic reconstructions in connection with the intoxication. As the liver performs a number of vital functions and is closely connected with regulatory systems of the organism, morphofunctional shifts in the organ affect unfavourably the system mother--fetus.     

Characteristics of action of precursors of carcinogenic nitroso-compounds on cell cultures

On the primary rat lung cell cultures, a study was made of the transforming action of sodium nitrite (NN) and amidopyrine combination with the control for formation of carcinogen--N-nitrosodimethylamine (NDMA) in growth medium. The manifestation of transformation was registered by appearance of morphological changes and multilayer growth foci. As criteria for evaluation after 48 hour treatments with NDMA, NN and AP, were used DNA-synthetizing activity of cells, mitotic index, frequency of mitoses pathology, monolayer density. The effects of transforming dose of NN alone and in combination with AP were the same. But malignization (tumor development in newborn rats in the points of cell suspension inoculation) took place only after administration of NN in combination with AP, when carcinogen was formed. Theophylline decreased the action of NN-AP combination.     

Structural-functional aspects of the postischemic recovery of the hepatocyte endoplasmic network in rats

The experiments on rats have shown that total hepatic ischemia reduces the content of microsomal cytochromes P-450 and b5 and causes amidopyrine and aniline disturbances over a 2-3-week post-ischemic period. The analysis of hepatocyte ultrastructure has revealed the interdependence of structural and functional changes in endoplasmic reticulum during recovery period. The damage of monooxygenase inducibility correlated with stable decline in the number of fixed ribosomes in post-ischemic period.     

Effect of N-nitrosodimethylamine and precursors of this carcinogen on rat kidney cells in monolayer culture

Kidney tissue culture of 3-day old rats was cultivated in the presence of carcinogenic N-nitrosodimethylamine (NDMA), sodium nitrite, amidopyrine and a combination of these substances forming NDMA. All these substances induce changes in the number of DNA-synthesizing cells, monolayer density, percentage ratio of epithelial and fibroblastoid cells in the kidney cultures. The above changes are typical of each of the tested components, that permits using one-layer culture of the rat kidneys as a model for investigating cell response to the precursors of NDMA and to this carcinogen.     

Prevention, using alpha-tocopherol and lidocaine, of damage to the monooxygenase system activity and ultrastructure of hepatocytes following acute ischemia of the liver

The experiments on rats have shown that alpha-tocopherol and lidocaine pretreatment leads to a decrease in the level of ischemic cell necrosis in the liver. The volume of cell necrosis in the liver was significantly decreased (more than threefold) in the case of drug pretreatment. The combination of alpha-tocopherol with lidocaine fully prevented the decrease in N-dimethylation of amidopyrine and cytochrome P-450 and b5 concentration, and the development of destructive alterations of cytoplasmic reticulum in the unaffected rat hepatocytes. alpha-Tocopherol and lidocaine pretreatment was effective for the retention of the depression of microsomal monooxygenases by phenobarbital in remote periods after acute hepatic ischemia.     

Sensitivity of larvae of Drosophila melanogaster mutant mus(2)201G1 to various analgesics

Sensitivity of larvae from mutagen-sensitive mus(2)201G1 mutant of Drosophila melanogaster to analgin, amidopyrine and antipyrine (4-64 mkmol/ml of medium) was studied. Relative frequency of flies homozygous for this mutation after combined development of homozygous and heterozygous flies in the medium with the analgetic was used as a criterion for larval sensitivity. It is shown that sensitivity of homozygotes was significantly higher than that of heterozygotes to all three analgetics. Relative sensitivity of homozygotes increased with the elevation of drugs concentration. The data obtained demonstrate the mutagenicity of the analgetics tested for Drosophila.     

Effect of exogenous and endogenous nitrosation factors on formation of N-nitrosodimethylamine in rats depending on the status of purine catabolism

Nitrogen dioxide's rats' inhalations with injections per os of pyrazole, amidopyrine and sodium nitrite lead to considerable increasing of endogenic N-nitrosodimethylamine formation, which had been determined by system gas chromatograph-thermal energetic analyser. This increasing essentially didn't depend on the rats' immunisation by vaccine BCG, which leads to the intensification of NO synthesis by peritoneal macrophages and others manifestations of their metabolic activation: increasing of creatine kinase and adenosine desaminase activities. It hadn't been brought to light the obvious dependent between changes of xanthine oxidase and xanthine dehydrogenase activities in the liver and blood serum and intensification of lipids peroxidation and also the amount of N-nitrosodimethylamine in the rats in the conditions of endogenic and exogenic nitrosation factors' influence.     

Methylmercury toxicity: amelioration by selenium and water‐soluble chelators as N‐acetyl cysteine and dithiothreitol

The protective potential of chelators, i.e. N‐acetyl cysteine (0.6 mg /kg, intraperitoneally) and dithiothreitol (15.4 mg kg^?1, intraperitoneally) with selenium (0.5 mg kg^?1, pre‐oral) were evaluated individually and in combination against methylmercury‐induced biochemical alterations and oxidative stress consequences. Forty‐two male Sprague–Dawley rats were exposed with methylmercury (1.5 mg kg^?1, pre‐oral) daily for 21 days followed by different treatments for five consecutive days. Administration of methylmercury caused significant enhancement in the release of transaminases, alkaline phosphatases and lactate dehydrogenases in serum. A significant increased was observed in lipid peroxidation level with a concomitant decreased in glutathione content after methylmercury exposure in liver, kidney and brain. Hepatic microsomal drug metabolizing enzymes (aniline hydroxylase and amidopyrine N‐demethylase) of cytochrome p4502E₁ showed sharp depletion after methylmercury exposure. Alterations in histological changes in liver, kidney and brain were also noted in methylmercury administered group. All treated groups showed recovery pattern, but the combined treatments with N‐acetyl cysteine and dithiothreitol in combination with selenium were more effective than that with either alone treatments in recovering blood biochemical changes after methylmercury toxicity. In conclusion, the results demonstrated that combination therapy may recover all blood biochemical alterations and offer maximum protection against methylmercury‐induced toxicity. Copyright © 2014 John Wiley & Sons, Ltd.     

Radioprotective effect of pyrazolone derivatives]

The intraperitoneal injection of analgin (1000 mg/kg), antipurine (400 mg/kg), amidopyrine (100 mg/kg) 3 hours before the irradiation of mice in a dose of 800 R led to survival of 30 to 45% of the animals (against 12.5% in control) and to increase in the average duration of life of the animals that perished. 80-95% of mice survived the period of "intestinal deaths" (the 7th day after the irradiation) after combined prophylactic use of purasolone derivatives and cystamine before the irradiation of these animals in a dose of 1050 R. The radioprotective effect of pyrasolone derivatives given in therapeutic doses was less pronounced.     

Rate of microsomal protein metabolism in the mouse liver

NaH14CO3, a poorly reutilized biosynthesis precursor, was used to study the rate of whole microsomal protein degradation in mouse liver. The use of the precursors, however, does not prevent the reutilization of labeled amino acids on phenobarbital administration. To avoid reutilization, a new method has been developed. It was shown that phenobarbital injections have no effect on the degradation rate of the whole microsomal protein. The effect of amidopyrine, a monooxygenase microsomal system substrate, on the rate of whole microsomal protein degradation was examined. An experimental model was developed, in which the monooxygenase microsomal system substrate does not exhibit the properties of its inducer. Amidopyrine administration to mice simultaneously with phenobarbital induction has no effect on the degradation rate of the whole microsomal protein.     

Propolis protects CYP 2E1 enzymatic activity and oxidative stress induced by carbon tetrachloride

Induction of CYP 2E1 by carbon tetrachloride (CCl₄) is one of the central pathways by which CCl₄ generates oxidative stress in hepatocytes. Experimental liver injury was induced in rats by CCl₄ to determine toxicological actions on CYP 2E1 by microsomal drug metabolizing enzymes. In this report, ethanolic extract of propolis at a dose of 200 mg/kg (po) was used after 24 h of toxicant administration to validate its protective potential. Intraperitoneal injection of CCl₄ (1.5 ml/kg) induced hepatotoxicity after 24 h of its administration that was associated with elevated malonyldialdehyde (index of lipid peroxidation), lactate dehydrogenase and γ-glutamyl transpeptidase release (index of a cytotoxic effect). Hepatic microsomal drug metabolizing enzymes of CYP 2E1 showed sharp depletion as assessed by estimating aniline hydroxylase and amidopyrine N-demethylase activity after CCl₄ exposure. Toxic effect of CCl₄ was evident on CYP 2E1 activity by increased hexobarbitone induced sleep time and bromosulphalein retention. Propolis extract showed significant improvement in the activity of both enzymes and suppressed toxicant induced increase in sleep time and bromosulphalein retention. Choleretic activity of liver did not show any sign of toxicity after propolis treatment at a dose of 200 mg/kg (id). Histopathological evaluation of the liver revealed that propolis reduced the incidence of liver lesions including hepatocyte swelling and lymphocytic infiltrations induced by CCl₄. Electron microscopic observations also showed improvement in ultrastructure of liver and substantiated recovery in biochemical parameters. Protective activity of propolis at 200 mg/kg dose was statistically compared with positive control silymarin (50 mg/kg, po), a known hepatoprotective drug seems to be better in preventing hepatic CYP 2E1 activity deviated by CCl₄. These results lead us to speculate that propolis may play hepatoprotective role via improved CYP 2E1 activity and reduced oxidative stress in living system.