Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The glutathione status of Plasmodium vinckei parasitized erythrocytes of mice was determined in correlation to the intraerythrocytic stage of maturation of the parasite. The different stages of blood schizogony were separated by discontinuous Dextran-density-centrifugation. The changes of protein content, glutathione concentration (reduced/oxidized and bound/free glutathione) and in the specific activities of the following enzymes: gamma-glutamyl-cysteine-synthetase (GC-synthetase), glutathione-reductase (GR), glucose-6-phosphate dehydrogenase (Gl-DH), glutathione-peroxydase (G-POD) and catalase were investigated in dependence of the intraerythrocytic stage of development. The following changes of the investigated metabolic parameters were observed during the schizogony: - the protein content decreased to about one half, - the glutathione concentration increased about 10-fold, while the relations reduced/oxidized and free/bound glutathione remained constant, - Gl-DH activity appeared and increased steeply, - the specific activities of GC-synthetase and of GR increased more than 2-fold, while G-POD remained almost constant, - and the activities of G-6-PDH and catalase showed a significant, strong decrease to about 25% of the original values. It is tried to relate the observed changes to the growing parasite or to the host cell. The significance of the results for the metabolism of malaria parasites and for a possible adaptation to the mosquito by a GSH mediated protection of the malaria parasite against an enzymatic defence-reaction of the mosquito, is discussed.
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PMID:[Glutathionestatus of Plasmodium vinckei parasitized erythrocytes in correlation to the intraerythrocytic development of the parasite (author's transl)]. 121 29

The present study was carried out to examine whether nitrofurantoin-induced pulmonary toxicity in normal rats was mediated via oxidant stress mechanisms. The relative importance of the cellular antioxidant enzymes in nitrofurantoin toxicity was also assessed. For this, the pulmonary toxicity induced by nitrofurantoin in rats was evaluated at various time intervals after a single subcutaneous injection. Data from this study showed that nitrofurantoin (200 mg/kg, s.c.) resulted in transient but measurable lung damage as evidenced by the increases in wet lung weight/body weight ratio and decreases in lung angiotensin converting enzyme activity. A transient decrease in GSH concentrations with a concurrent increase in GSSG concentrations as well as an increase in lipid peroxidation levels (measured by the formation of diene conjugates and thiobarbituric acid reactants) were also evident in lungs of nitrofurantoin-treated rats. In addition, nitrofurantoin did not alter the pulmonary superoxide dismutase and glutathione peroxidase activities, but it did produce transient decreases in catalase and glutathione reductase activities. These data indicate that impairment of the ability of the lung to detoxify reactive oxygen species may play an important role in the development of nitrofurantoin-induced pulmonary toxicity. The results of the present study suggest that nitrofurantoin can damage the lungs of rats, probably through oxidative stress-mediated mechanisms. Also, our data have provided in vivo evidence for substantiating lipid peroxidation as a possible cause of lung damage.
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PMID:Nitrofurantoin-induced pulmonary toxicity. In vivo evidence for oxidative stress-mediated mechanisms. 131 37

Xenobiotics metabolized in rat pulmonary tissue are often selectively cytotoxic to individual lung cell populations. A non-homogeneous distribution of xenobiotic biotransformation enzymes, e.g., cytochrome P-450 (P-450)- and glutathione (GSH)-associated enzymes, in rat lung tissue may underlie this observed cell-selective pneumotoxicity. To evaluate this hypothesis, the relative activities of P-450- and GSH-associated enzymes were measured in sonicated, freshly isolated preparations containing enriched complements of individual toxicant-sensitive lung cell types, including non-ciliated bronchiolar epithelial (Clara) cells (24% pure), alveolar type II cells (86% pure) and pulmonary endothelial cells (identified by membrane-associated angiotensin converting enzyme activity). Lung cell fractions were isolated by centrifugal elutriation from male F344 rats that 48 h earlier received a single i.p. injection of either P-450-inducer beta-naphthoflavone (50 mg beta-NF/kg body weight) or corn oil vehicle. The enriched Clara cell fraction possessed (per 10(6) cells) greater P-450 and reduced GSH contents and higher enzyme activities (i.e., NADPH- and NADH cytochrome c reductases, benzyloxy (BROD)-, pentoxy (PROD)- and etoxyresorufin (EROD)-O-dealkylases, GSH transferase, GSH peroxidase, GSH reductase and NADPH quinone oxidoreductase) than either the enriched type II cell or endothelial cell preparations. However, the relative biochemical activities for the enriched fractions (Clara greater than type II greater than endothelial) generally reflected respective sonicate cellular protein content. Treatment of rats with beta-NF resulted in: (a) an induction in EROD activity in the enriched preparations of type II cells, Clara cells and endothelial cells (125-, 89- and 35-fold, respectively); (b) higher NADPH quinone oxidoreductase activities, which were increased to the greatest degree (3-fold) in the enriched type II cell fraction and (c) a small elevation in GSH transferase activity measured in the enriched Clara cell fraction. Although the enriched rat lung cell preparations possessed unique biochemical profiles for constitutive and beta-NF-inducible P-450- and GSH-associated enzymes, additional studies with higher purity preparations (e.g., Clara cells) will be required to more fully evaluate the relationship between relative cellular complements of xenobiotic biotransformation enzymes and pneumotoxicant susceptibility.
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PMID:Cytochrome P-450- and glutathione-associated enzyme activities in freshly isolated enriched lung cell fractions from beta-naphthoflavone-treated male F344 rats. 160 25

As many as 160 patients with acute virus hepatitis B (AVHB) were examined over time. Spectroscopy was used to study the activity of glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase-1 (GP1), glutathione peroxidase-2 (GP2), glutathione reductase (GR), glutathione transferase (GT) and to measure the concentration of reduced glutathione (GSH) in the blood serum and in red blood cells. Within the first days of the icteric period, the activity of all the enzymes rose, followed by reduction of the activity of G-6-PDH, GP1, GP2, GR and the concentration of GSH at the height of the disease. The GT activity remained high throughout the entire disease period.
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PMID:[The functioning of the glutathione system in patients with acute viral hepatitis B]. 233 29

The effect of manganese exposure (Mn2+ 4 mg Mn/kg intraperitoneally) on certain bioantioxidants in brain, liver, kidney and testes in growing rats maintained on 21% and 8% casein diet were investigated. Manganese administration for 30 days caused significant reduction in the level of GSH (reduced glutathione) in liver and testes and GR (glutathione reductase) and G-6-PDH (glucose-6-phosphate dehydrogenase) in brain, liver and testes. The magnitude of alteration was greater in 8% casein diet fed animals compared to rats maintained on 21% casein diet. These results indicate that protein deficient animals are more susceptible to the manganese induced biochemical changes in various tissues. The mechanism of such changes is discussed.
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PMID:Effect of manganese on some bioantioxidants in various organs of protein-deficient rats. 278 47

The activity of angiotensin converting enzyme(ACE) in crude extracts of the rat renal cortex was increased when the oxidizing agent diamide was added to the extract. The maximal activity was obtained at concentrations over 1 mM, and the value was twice or more the activity in the absence of the pretreatment. The activity of ACE was also increased by the diamide-pretreatment of the isolated membrane fraction of the renal cortex, thereby indicating that the increase in activity was not due to oxidation of endogenous glutathione (GSH) that may lower the ACE activity, but rather that ACE itself was oxidized. When O2 was included in the extract for 2 h, the ACE activity also increased to about twice the original activity. Lineweaver-Burk plots analysis demonstrated that, after oxidation with diamide and O2, the Vmax was increased but the Km remained unchanged. We conclude that the action of ACE in the kidney functions may differ in relation to oxidation of the tissue.
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PMID:Oxidation-induced increase in activity of angiotensin converting enzyme in the rat kidney. 283 67

At the present time, comprehensive metabolism studies of 2,3-dichloro-1-propene (2,3-DCP) have not yet been reported. We have investigated the biotransformation of 2,3-DCP using female Wistar rats in order to elucidate the bioactivation mechanisms. 175 mg/kg, 1,3-14C-2,3-DCP in corn oil was administered to a rat. The animal was killed 20 hr later. Approximately 56.7% of the radioactivity was excreted in the urine, 1.6% in the feces, 5.3% was exhaled as unchanged 2,3-DCP, and 0.3% as CO2. 31.3% remained in the organs and the carcass. Three metabolic pathways were established. 1) Conjugation with GSH leading to S-(2-chloro-2-propenyl)mercapturic acid. 2) The P450 induced epoxidation with subsequent rearrangement to highly mutagenic 1,3-dichloroacetone. 1,3-Dichloroacetone was further converted to the dimercapturic acid, 1,3-(2-propanone)-bis-S-(N-acetylcysteine). 3) The hydrolysis to 2-chloroallyl alcohol followed by alcohol dehydrogenase catalyzed formation of highly mutagenic 2-chloroacrolein. The 2-chloroallyl alcohol is excreted directly in the urine and as the glucuronide. 2-Chloroacrolein is further oxidized to 2-chloroacrylic acid which is also excreted in the urine.
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PMID:Metabolism of 2,3-dichloro-1-propene in the rat. Consideration of bioactivation mechanisms. 289 57

Studies were conducted to assess the in vitro toxicity of three chloropropanones: monochloropropanone (MCP), 1,1-dichloropropanone (1,1-DCP), and 1,3-dichloropropanone (1,3-DCP). Chloropropanones reacted directly with reduced glutathione (GSH) in sodium phosphate buffer at pH 7.4. All chloropropanones were cytotoxic to suspensions of male rat hepatocytes in a concentration range of 0.5-10 mM. Cytotoxicity was preceded by rapid decline in cellular GSH levels. Mutagenic potencies among the chloropropanones in Salmonella typhimurium bacteria differed greatly. 1,3-DCP was mutagenic in the nanomole range, 1,1-DCP was weakly mutagenic in the micromole range, and MCP was not mutagenic. Mutagenicity of the dichloropropanones was evident without metabolic activation. These results suggest that the three chloropropanones may, in part, be directly cytotoxic but only 1,3-DCP and 1,1-DCP are directly mutagenic.
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PMID:Chemical reactivity, cytotoxicity, and mutagenicity of chloropropanones. 331 10

Glucose-6-phosphate dehydrogenase (G-6-PDH) is the key enzyme of the pentose phosphate cycle and therefore regulates the synthesis of the nucleic acid constituent ribose-5-phosphate. At the same time the enzyme is coupled to the synthesis of reduced glutathione (GSH) which detoxifies electrophilic molecules (radicals) in the organism. Activity and stability of G-6-PDH and the influence of SIN 1--the active metabolite of molsidomine (Corvaton)--dithiothreitol (DTT) and NADP on these parameters were studied in enzyme preparations from different organs of the rat (liver, ethmoturbinates, blood) and from blood of mouse, guinea pig, rabbit, dog and man. The highest activity of G-6-PDH was measured in rat ethmoturbinates (69.26 +/- 5.91 mU/mg protein/min), the lowest in human blood (2.99 +/- 0.18 mU/mg protein/min). G-6-PDH of rat ethmoturbinates and of rat and dog blood was unstable and nearly completely inhibited by SIN 1. The enzyme of rat liver and of human, mouse, guinea pig and rabbit blood was stable and not influenced by SIN 1. These organ-and species-specific findings are discussed with respect to the toxicological actions of SIN 1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Organ- and species-specific properties of glucose-6-phosphate dehydrogenase and the effect of molsidomine]. 336 74

The effects of aerosols of cadmium chloride (CdCl2) and cadmium oxide (CdO) on pulmonary biochemical function were compared. Rats and rabbits were exposed to 0.25, 0.45, or 4.5 mg Cd/m3 for 2 h. Pulmonary toxicity was determined histologically and biochemically. Cadmium chloride and CdO showed a deposition response that was linearly related to the chamber concentration. Both compounds caused multifocal, interstitial pneumonitis 72 h after exposure, but the CdO lesion was more severe with proliferation of fibrocytic-like cells as well as pneumocytes. Comparing the two Cd compounds at the highest concentration (4.5 mg Cd/m3), the biochemical responses in the rat were similar. The majority of the effects occurred 72 h after exposure, with significant increases in lung weight, lung-to-body weight ratio, GSH reductase, GSH transferase, and G-6-PDH. However, GSH peroxidase was inhibited immediately after the CdO exposure. Cadmium oxide-related alterations in the parameters studied could easily be distinguished from those of CdCl2 at the exposure concentration of 0.45 mg Cd/m3. The response pattern in the rabbit resembled that of the rat. In both species Cd had a consistent inhibitory effect on pulmonary GSH peroxidase, even at the lowest concentration of 0.25 mg Cd/m3. Based on these findings, inhaled CdO appeared to be more toxic to the lung than inhaled CdCl2.
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PMID:A comparative study of the effects of inhaled cadmium chloride and cadmium oxide: pulmonary response. 357 72


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