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)

Activities of glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase were measured in the blood of 38 patients with acute nonepidemic parotitis and the status of glutathione antioxidant system assessed. The predominance of free-radical processes in the mechanisms of impairment of the parotid gland was confirmed. Increased level of lipid peroxidation products and decompensation of glutathione antioxidant system were found to be due to incompetence of the malate shuttle and low activity of G-6-PDH. A conclusion is made about the necessity of revising current approaches to prevention and therapy of acute nonepidemic parotitis.
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PMID:[The activity of the glutathione antioxidative system in the blood of patients with acute nonepidemic parotitis]. 757 Jun 96

In order to clarify the preventive action of Dai-Saiko-to (Da-Chai-Hu-Tang) extract (TJ-8) on the progression of acute liver injury in rats intoxicated with carbon tetrachloride (CCl4), we examined the effect of post-oral TJ-8 administration on hepatic active oxygen metabolism following the progression of this liver damage. When TJ-8 (1.0 g/kg body weight) was administered orally to male Wistar rats aged five weeks 2 hrs after i.p. injection of CCl4 (1.0 ml/kg body weight), an apparent liver injury occurred. Significant prevention against the progression of liver injury was found at 24 hrs after injection, judging from the activities of serum transaminases, indexes of liver cell damage. Liver cytosolic superoxide dismutase (SOD) activity decreased 2 and 24 hrs after CCl4 injection, while liver cytosolic catalase and glutathione reductase (GSSG-R) activities decreased 24 hrs after the injection. At 2 and 24 hrs after CCl4 treatment, liver cytosolic Se-containing glutathione peroxidase (GSH-px) activity did not change and liver cytosolic glucose-6-phosphate dehydrogenase (G-6-PDH) activity increased. Post-oral TJ-8 administration significantly ameliorated decreases in liver SOD, catalase, and GSSG-R activities at 24 hrs after CCl4 injection, but did not affect liver Se-GSH-px and increased liver G-6-PDH activities at 24 hrs after the injection. Although increased liver lipid peroxide level and decreased liver reduced glutathione and ascorbic acid levels were observed 2 and 24 hrs after CCl4 injection, post-oral TJ-8 administration significantly prevented these changes found at 24 hrs after injection. These results indicate that post-oral TJ-8 administration can prevent the progression of acute liver injury in CCl4-injected rats by inhibiting enhanced lipid peroxidation and by improving disrupted active oxygen metabolism in the injured liver.
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PMID:Preventive effect of dai-saiko-to (da-chai-hu-tang) extract on disrupted hepatic active oxygen metabolism in rats with carbon tetrachloride-induced liver injury. 759 92

Previous cell culture evaluations have shown that nickel-chromium dental alloys did not affect cellular viability or morphology. However, nickel-based alloys released corrosion products which decreased cellular proliferation. It was hypothesized that this decrease was due to an interference of cellular energy metabolism by released metal ions. To test this hypothesis, we evaluated the effects on cellular energy metabolism, adenosine triphosphate (ATP) levels, and cellular ultrastructure by four nickel-based alloys, including high and low chromium alloys with and without beryllium additions, in human gingival fibroblast cell cultures. Energy metabolism was evaluated by measuring glucose-6-phosphate dehydrogenase (G-6-PDH) activity. ATP levels were measured with the luciferin-luciferase method. Cellular membranes and ultrastructural organization were evaluated by scanning and transmission electron microscopy. The results of this study showed that metal ions released from all alloys completely inhibited G-6-PDH activity and reduced cellular ATP levels as compared to controls. The reduction in intracellular ATP was greater for the beryllium containing alloys than the non-beryllium-containing alloys. However, no morphologic changes in cellular membranes or organelles were observed. These results support the hypothesis that metal ions released from nickel-based dental casting alloys interfere with cellular energy metabolism.
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PMID:Effect of nickel-based dental casting alloys on fibroblast metabolism and ultrastructural organization. 762 46

Mitochondrial manganese-containing SOD (MnSOD) is located at the primary site of O2 metabolism, and its expression may be regulated by changes in O2 level. We hypothesized that lung MnSOD expression and promoter activity would decrease in response to hypoxia. We tested effects of hypoxia (10% O2 at sea level for 7 days) on chloramphenicol acetyltransferase (CAT) reporter and MnSOD gene expression in transgenic mice. The transgene consisted of a 3.3-kb portion of the rat MnSOD gene 5' flanking region coupled to a CAT reporter gene. Lung MnSOD activity in male (but not female) mice decreased significantly after hypoxia exposure. The decrease in MnSOD enzymatic activity in male mice was specific. Neither total SOD nor glucose-6-phosphate dehydrogenase (G-6-PDH) activity decreased significantly in hypoxia. CAT protein expression decreased in transgenic males exposed to hypoxia, while CAT protein expression in hypoxic transgenic females remained comparable with controls. The mRNA for both the native MnSOD and the MnSOD-CAT reporter genes remained constant after hypoxia, as did CuZnSOD and G-6-PDH mRNAs.
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PMID:Effects of hypoxia on MnSOD expression in mouse lung. 765 84

In the course of a long-term L-DOPA administration (14 days) and 2 weeks after its cessation the activities of some protein enzymes (aminopeptidase, acid phosphatase), neuromediator (MAO, ACE) and oxidative (glutamate dehydrogenase, glucose-6-phosphate dehydrogenase) metabolism were studied by quantitative cytochemical methods in brain motor structures (sensorimotor cortex, caudate nucleus) and in structures not directly related to motor functions (hippocampus) of rats with high and low motor activity. After L-DOPA (madapar) cessation significant changes were revealed in the formation of motor system of the brain, primarily in the group of rats with low motor activity. It is suggested that a decrease in MAO activity after madapar cessation may be responsible for dyskinesia arising after cessation of L-DOPA preparations treatment.
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PMID:[Pathochemical changes in the motor structures of the brain under the influence of the administration of L-DOPA preparations and their withdrawal (experimental research)]. 790 Apr 46

Changes in superoxide dismutase (SOD), catalase (C), and peroxidase (P) blood activity, as well as the activity of glucose-6-phosphate dehydrogenase (G-6-PDH), isocitrate dehydrogenase (ICDH), malate dehydrogenase (MDH), and peroxide resistance of erythrocytes (PRE) have been studied in 45 gastroenterologic patients under different types of general anesthesia. A significant increase in G-6-PDH, SOD, K, P activity and an increase in ICDH and MDH activity, as well as a drop in PRE which tends to return to baseline postoperatively have been established during general anesthesia. SOD expressed the greatest intergroup differences. A fragment of mechanism of energy transfer in the erythrocyte aimed at hemoglobin oxygenation and tissue hypoxia compensation has been suggested.
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PMID:[Effects of general anesthesia on the regulation of hydrogen peroxide metabolism in erythrocytes]. 801 May 17

Incubation of glucose-6-phosphate dehydrogenase (Glu-6-PDH) from Leuconostoc mesenteroides with the lipid peroxidation product 4-hydroxy-2-nonenal leads to the formation of cross-linked protein. This is accompanied by the appearance of protein-associated fluorescence with excitation and emission maxima of 340 and 415 nm, respectively, and with the disappearance of histidine and lysine residues. Cross-linked protein is less susceptible than native Glu-6-PDH to proteolysis by the multicatalytic protease, a multienzymic proteolytic complex involved in the intracellular degradation of damaged proteins. In addition, 4-hydroxy-2-nonenal-modified Glu-6-PDH inhibits the multicatalytic protease and can therefore prevent the efficient degradation of oxidized protein. These findings may have important implications for the accumulation of altered protein and fluorescent material in vivo, processes that are believed to be involved in age- and disease-related impairment of cellular function.
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PMID:Modification of glucose-6-phosphate dehydrogenase by 4-hydroxy-2-nonenal. Formation of cross-linked protein that inhibits the multicatalytic protease. 806 6

Facilitation of protein folding by GroEL usually requires involvement of GroES and ATP. In their absence nascent proteins tend to be arrested on GroEL or, if released, fail to show enhancement of reactivation yield relative to that observed without the chaperonin. In contrast, the yield of reactivation of glucose-6-phosphate dehydrogenase (Glu-6-PDH) from Leuconostoc mesenteroides at 20 degrees C is increased 2-3-fold (to over 80%) by GroEL alone. ATP greatly enhances the rate of GroEL-assisted reactivation and slightly increases its yield to 90%. The efficiency of the GroEL-assisted reactivation of Glu-6-PDH is strongly dependent on temperature. A switch from enhanced to fully arrested reactivation occurs over a narrow temperature range from 25 to 30 degrees C in the presence of GroEL when ATP is absent. At physiological temperature therefore, reactivation is fully arrested by GroEL if ATP is absent and in its presence the protein is released in a form not committed to correct folding. The data shows that the committing step in Glu-6-PDH refolding occurs while the nascent protein is bound to GroEL, a step which is temperature-sensitive. The extreme temperature sensitivity of this step indicates a sharp structural transition in GroEL.
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PMID:Thermal switching between enhanced and arrested reactivation of bacterial glucose-6-phosphate dehydrogenase assisted by GroEL in the absence of ATP. 810 42

Utilization of highly enriched preparations of steroidogenic Leydig cells have proven invaluable for studying the direct effects of various hormones and agents on Leydig cell function in vitro. However, recent work indicates that isolated Leydig cells are often subjected to oxygen (O2) toxicity when cultured at ambient (19%) oxygen concentrations. Because intracellular antioxidants play an important role in protecting cells against oxygen toxicity, we have investigated the intracellular antioxidant defense system of isolated Leydig cells. The cellular levels of several antioxidants including catalase, glucose-6-phosphate dehydrogenase (G-6-PDH), superoxide dismutase (SOD) of the Cu/Zn & Mn variety, glutathione peroxidase, glutathione reductase and total glutathione were quantitated using enriched populations of Leydig cells isolated from adult male guinea pig testes. Compared to whole testicular homogenates, Leydig cells contained significantly (P < 0.01) less G-6-PDH, total SOD, glutathione reductase and total glutathione, but significantly (P < 0.001) more glutathione peroxidase. Compared to hepatic values previously reported in the guinea pig, Leydig cells contain nearly 400 times less catalase, about 14 times less glutathione peroxidase and almost 11 times less glutathione reductase. Since G-6-PDH and glutathione reductase are both necessary to regenerate reduced glutathione (GSH) which couples with glutathione peroxidase to breakdown hydrogen peroxide (H2O2) under normal conditions, it is plausible that the oxygen toxicity observed in isolated Leydig cells is due to the intracellular accumulation of H2O2.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The antioxidant defense system of isolated guinea pig Leydig cells. 810 85

The activities of malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G-6-PDH), two NADPH-generating lipogenic enzymes, were measured in brown adipose tissue (BAT) of rats undergoing various neurohormonal manipulations. Methimazole-induced hypothyroidism doubled the activity of these two enzymes but, surprisingly, triiodothyronine (T3) given to hypothyroid rats caused a time- and dose-dependent stimulation of up to three- to fourfold. Unilateral BAT denervation modestly reduced the activity of these enzymes (approximately 30%) and failed to prevent the stimulation induced by hypothyroidism, whereas growth hormone (GH) successfully blocked this effect of hypothyroidism. Insulin stimulated both enzymes regardless of the thyroid status but failed to abolish the inhibitory effect of GH. In intact rats, cold exposure caused a time-dependent increase in the activity of both ME and G-6-PDH, which reached 5.2- and 3-fold, respectively, after 96 h. This cold-induced stimulation was not observed in hypothyroid rats, but it was restored by physiological doses of thyroxine (800 ng.100 g body wt-1.24 h-1). Replacement with T3 (300 ng.100 g body wt-1.24 h-1), in contrast, did not have this effect. In hypothyroid rats with hemidenervation of BAT, norepinephrine (NE) modestly increased ME and G-6-PDH activities in the denervated side, with little or no effect in the intact side. Receptor-saturating doses of T3 (50 micrograms.100 g body wt-1.day-1 over 48 h) stimulated two- and threefold both enzymes in both sides, reducing or obliterating the effect of denervation. The data suggest a complex neurohormonal regulation of the activity of ME and G-6-PDH in BAT.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hormonal regulation of malic enzyme and glucose-6-phosphate dehydrogenase in brown adipose tissue. 833 12


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