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)

Treatment of male guinea-pigs daily with an oral dose of 2 mg dehydroepiandrosterone (DHA) sulphate/100 g body weight for 2 weeks significantly reduced the glucose-6-phosphate dehydrogenase (G-6-PDH) activity of erythrocytes, liver, kidney and testis. Lactate dehydrogenase activity in plasma also decreased, but L-aspartate: 2-oxoglutarate aminotransferase (GOT) and L-alanine:2-oxoglutarate aminotransferase (GPT) activity in plasma remained unaffected. In liver and kidney, however, a significant rise in GOT and GPT was observed. A 2- to 3-7-fold increase of C19-steroids was observed in plasma, liver and kidney. In extracts of liver and kidney more than 60% of steroids were isolated from the sulphatide fraction. Only minor changes were detected in the metabolic pattern of C19-steroids, 17-hydroxysteroids prevailing in the free and sulphatide fractions, while 17-oxosteroids predominated in the sulphate and glucuronide fractions. A slight rise of cyclic AMP concentrations in liver and kidney tissue was attributed to the inhibition of phosphodiesterase by the DHA/G-6-PDH system
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PMID:Effects of exogenous dehydroepiandrosterone sulphate on various enzymes and on steroid metabolism in the guinea-pig. 13 7

To assess mitochondrial function (pyruvate dehydrogenase [PDH] activity), cells were grown in the appropriate media to confluence, rinsed and incubated in glucose free media containing 25 microM L-lactate and [1-14C]-D,L-lactate. Lactate oxidation was measured as the amount of lactate oxidized in nmol of 14CO2 generated per mg of protein per minute. Basal activity varied with cell number and the cell type studied: fibroblast 2.26 +/- 0.01; Chinese hamster ovary (CHO) 42 +/- 0.4; BC3H-1 52 +/- 2.1 nmol per mg per minute. The CHO cells screened for PDH activity decreased their dependence on lactate as a substrate in the presence of 5mM glucose by 60 percent. Increasing the cold lactate concentration diluted the labelled lactate available for pyruvate oxidation in a dose dependent manner. The mitochondrial inhibitor rotenone (25 microM) decreased assay activity by > 75 percent in CHO and BC3H-1 cells. The lactate oxidation assay was shown to be sensitive enough to measure insulin stimulation of PDH in a dose dependent manner with maximum activity occurring at concentrations between 1 microU per ml and 100 microU per ml.
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PMID:Assessment of mitochondrial function in cells grown in tissue culture. 145 30

ATPase activity of uterus and ovary was markedly elevated in presence of gossypol and decreased in presence of lactic acid indicating activation and inhibition of energy metabolism by gossypol and lactic acid respectively. The elevated levels of glycogen in uterus indicate inhibition of glycogenolysis as supported by phosphorylase activity. Whereas in ovary the glycogen depletion indicates activation of glycogenolysis supported by phosphorylase activity. The activity levels of aldolase and G-6-PDH decreased in the uterus in presence of gossypol and increased in presence of lactic acid. The same were elevated in ovary indicating the activation of hexose mono and diphosphate pathways. Lactic acid accumulated in presence of both gossypol and lactic acid with a depletion in level of pyruvic acid in both the tissues. This situation in the uterus indicates the condition of anti-implantation in presence of both gossypol and lactic acid. The NAD-LDH activity was inhibited in presence of gossypol and activated in presence of lactic acid in both tissues.
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PMID:In vitro effects of gossypol and lactic acid on rat uterus and ovary during implantation and antiimplantation. 263 59

The possibility of in situ isolated lung perfusion as a means of treating nonresectable pulmonary cancers unresponsive to conventional chemotherapy has been investigated. The present study has examined the biochemical and morphological effects of in situ isolated lung perfusion in dogs with doxorubicin (DOX). A dose related complication was seen in the animals following lung perfusion. Lactate dehydrogenase (LDH) activity in the perfusate increased as dose was increased, indicating tissue damage during the perfusion. Up to 7 days postperfusion, marked changes were seen in the serum protein concentrations although these were independent of doxorubicin concentrations. Serum lactate dehydrogenase showed a dose dependent increase 2 hour and 1 day after the lung perfusion. Plasma angiotensin converting enzyme activities up to 14 days postperfusion suggested that DOX produced pulmonary endothelial cell injury at higher drug doses. Histopathologic examination of the lungs from dogs receiving the highest concentrations of drug indicated that necrosis of arterial endothelia and alveolar epithelia accompanied by periarterial edema, subplural edema and emphysema of the lungs were the probable causes of acute animal mortality. The study has demonstrated that doxorubicin produces dose-dependent damage to the pulmonary tissue. However, the observed injury only appeared life-threatening at perfusate drug concentrations in excess of 20 nmol/ml. In situ lung perfusion for the treatment of unresectable pulmonary tumors may be clinically applicable.
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PMID:Pulmonary toxicity of doxorubicin administered by in situ isolated lung perfusion in dogs. 283 Sep 58

To elucidate the role of bradykinin in the cardiac actions of angiotensin converting enzyme (ACE) inhibitors, experiments were performed in isolated ischaemic hearts from guinea pigs and rats treated with the ACE inhibitor ramipril and the bradykinin-antagonist D-Arg[Hyp2,Thi5,8,D-Phe7]BK. In guinea pig hearts bradykinin increased coronary flow. Single oral pretreatment with ramipril (10 mg/kg) potentiated but perfusion with the bradykinin antagonist abolished this effect. In ischaemic working rat heart preparations perfusion with ramiprilat (2.58 x 10(-7) mol/l) or single oral pretreatment with ramipril (1 mg/kg) protected the heart from the ventricular fibrillations that invariably occurred upon reperfusion after ischaemia. Lactate dehydrogenase and creatine kinase activities, as well as lactate formation, were decreased in the venous effluent of pretreated hearts. Moreover, ACE inhibition in the heart improved cardiodynamic and metabolic parameters; left ventricular pressure, (dp/dt)max and coronary flow were increased and myocardial tissue levels of glycogen, ATP and creatine phosphate were elevated. A comparable array of changes was seen when rat hearts were perfused with bradykinin (1 x 10(-10) mol/l), which reduced enzymatic activities in the perfusate and improved the metabolic parameters in the myocardium. These cardioprotective effects produced by both the ACE inhibitor ramipril and bradykinin were completely abolished when the bradykinin-antagonist (1 x 10(-5) mol/l) was added to the perfusate. They were only partially attenuated when indomethacin (1 x 10(-6) mol/l) was perfused. Higher concentrations of bradykinin (1 x 10(-7) mol/l) or ramiprilat (2.58 x 10(-5) mol/l) overcame the actions of the bradykinin-antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of the angiotensin converting enzyme inhibitor, ramipril, in isolated ischaemic rat heart are abolished by a bradykinin antagonist. 285 32

1. Cardiorespiratory effects of long-term, continuous i.v. administration of the ACE inhibitor enalaprilat were studied. 2. Forty-five consecutive critically patients suffering from trauma or postoperative complications were randomly separated into three groups (15 patients in each group) receiving either 0.25 mg h-1 or 0.50 mg h-1 enalaprilat, respectively, or saline solution as placebo (= control group). The infusion was continued for 5 days. 3. Haemodynamic and respiratory parameters were intensively monitored on admission to the intensive care unit (= 'baseline' values) and daily during the next 5 days. 4. Mean arterial blood pressure (MAP) decreased significantly only in the enalaprilat-treated patients, whereas heart rate (HR) remained unchanged in these patients. 5. Pulmonary capillary wedge pressure (PCWP) and pulmonary artery pressure (PAP) were decreased by enalaprilat (0.50 mg h-1: PAP (mean +/- s.d.) decreased from 28.0 +/- 4.1 to 24.0 +/- 3.0 mm Hg) and remained significantly lower than in the control group. In the untreated control group, cardiac index (CI), oxygen consumption (VO2I) and oxygen delivery (DO2I) significantly decreased, which was blunted by enalaprilat infusion. Oxygen extraction (O2-extr) increased in both enalaprilat groups (0.25 mg h-1: from 26.1 +/- 5.5 to 30.4 +/- 4.0%; 0.50 mg h-1: 25.2 +/- 5.6 to 30.9 +/- 4.4%) and decreased in the control patients. 6. Right ventricular haemodynamics improved by enalaprilat infusion (0.50 mg h-1: RVEF increased from 40.0 +/- 3.5 to 45.5 +/- 4.0%). Lactate plasma concentrations decreased in the group with 0.50 mg h-1 enalaprilat (from 1.9 +/- 1.0 to 1.3 +/- 0.3 mg dl-1) and increased in the control patients. 7. Continuous infusion of the ACE inhibitor enalaprilat exerted beneficial cardiorespiratory effects in the critically ill. The widespread common risk of altered perfusion with decreased CI, DO2, VO2, O2-extr and increased lactate concentration was blunted by enalaprilat infusion. 8. Although 0.5 mg h-1 enalaprilat was most effective, a dose of 0.25 mg h-1 also showed beneficial haemodynamic effects in the critically ill.
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PMID:Cardiorespiratory effects of continuous i.v. administration of the ACE inhibitor enalaprilat in the critically ill. 870 44

Chronic hypoxia has been shown to increase plasma endothelin levels. The current study was undertaken to examine the effect of exercise-induced tissue hypoxia on plasma levels of endothelin-1 (ET-1) and its precursor big endothelin-1 (Big-ET-1). After approval by the local ethical committee an incremental dynamic exercise test was performed in 12 physically trained volunteers (aged 20 to 40 years), using an electrically braked bicycle ergometer. The protocol included a step-wise increase of the workload until a heart rate of 130/min was reached, followed by a maintenance period of 25 min, and a further step-wise increase until exhaustion. Blood was drawn before, at several time points during, and 5 min after termination of the study for determination of ET-1, Big-ET-1, plasma renin activity (PRA), angiotensin converting enzyme (ACE), norepinephrine, epinephrine, and lactate. Lactate levels at baseline were 14.5 +/- 1.6 mg/dL (mean +/- SEM), which increased to 76.5 +/- 4.8 mg/dL at the time of exhaustion (P < .01). Baseline values for ET-1 and Big-ET-1 were 0.264 +/- 0.061 and 0.637 +/- 0.130 fmol/ml, respectively, which remained essentially unaltered throughout the exercise test. PRA was 1.46 +/- 0.45 ng/mL/h before exercise and increased to 3.55 +/- 0.96 ng/mL/h at exhaustion (P < .001). Norepinephrine and epinephrine were also increased at exhaustion. The study demonstrates that exhaustive physical exercise with acute development of pronounced tissue hypoxia--in contrast to chronic hypoxia--does not influence the release of ET-1 or Big-ET-1 or the conversion of the precursor to the active compound. Unlike endothelin, circulating renin and the catecholamines were markedly stimulated by this maneuver.
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PMID:Exhaustive exercise-induced tissue hypoxia does not change endothelin and big endothelin plasma levels in normal volunteers. 971 98

Tight glycemic control during diabetic pregnancy has been shown to significantly reduce the occurrence of congenital malformations and other effects of maternal diabetes on the offspring. However, intensive insulin therapy often causes recurring acute maternal hypoglycemia, which has been found to be harmful to the developing fetus, although the mechanisms involved are not clear. The aim of our work was to study the effect of acute insulin-induced maternal hypoglycemia on glucose metabolism in the fetal brain. To this end, near-term pregnant New Zealand rabbits were rendered hypoglycemic, and [U-(13)C]glucose was infused into maternal circulation. The metabolic fate of the (13)C-labeled glucose was then studied in fetal brain extracts by (13)C NMR isotopomer analysis, together with conventional biochemical assays of glucose and lactate levels in both plasma and brain. For comparison [U-(13)C]glucose was also administered to insulin-induced hypoglycemic young adult rabbits. Our results showed that while plasma glucose levels were significantly reduced (approximately 70%) relative to controls, no changes in cerebral glucose levels could be detected. Lactate levels were found to be significantly decreased in hypoglycemic fetal plasma and brain. No differences in lactate levels between control and hypoglycemic young rabbit plasma and brain were observed. These differences were attributed to the utilization of lactate as an energy substrate in the fetal brain, but not in the adult brain. Higher relative (13)C enrichments of most glucose metabolites, except lactate, in the hypoglycemic fetal and young rabbit brains, observed by (13)C NMR, stem from reduced endogenous plasma glucose pools, thereby diluting the labeled glucose to a lower extent. The relative glucose (or glucose-derived lactate) flux via the pyruvate carboxylase and pyruvate dehydrogenase pathways (PC/PDH ratio) was not altered under hypoglycemic conditions in the fetal brain for both glutamine and glutamate, but significantly increased in the adult brain for both glutamine and glutamate. The presented data indicate the ability of the fetal brain to maintain energy metabolism during acute hypoglycemia, via lactate utilization. The increase in the adult PC/PDH ratio was suggested by us to stem from increased PC activity, in order to replenish TCA cycle intermediates.
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PMID:Effect of acute insulin-induced hypoglycemia on fetal versus adult brain fuel utilization, assessed by (13)C MRS isotopomer analysis of [U-(13)C]glucose metabolites. 1111 Nov 61

Restitution of bronchial artery circulation might alter ischemia- reperfusion injury and improve organ function after lung transplantation. Weight-matched dogs underwent a left lung allotransplantation either with bronchial artery revascularization (BAR; n = 6) or as conventional lung transplantation (LTX; n = 6), to evaluate effects of BAR on lung cell function over a period of 5 h postischemically. Lactate dehydrogenase (LDH) and marker enzymes for pneumocytes type I (carboxypeptidase M [CPM], pneumocytes type II (alkaline phosphatase [AP]), and pulmonary endothelium (angiotensin-converting-enzyme [ACE]) were determined from bronchoalveolar lavage fluid. Donor lungs were preserved with Euro-Collins solution. Total ischemic time was kept at 6 h. CPM and LDH activities were significantly higher in both groups at 2 h and 4 h of reperfusion compared with control dogs (p < 0.01). AP and ACE activities in lavage after 2 h of reperfusion were significantly elevated in animals that underwent LTX (AP: 60 +/- 28 IU/L; ACE: 1.39 +/- 1.13 IU/L) compared with animals with BAR (AP: 33 +/- 29 IU/L; ACE: 0.35 +/- 0.6 IU/L; p < 0.05) and with control animals (AP: 13.58 +/- 11.0 IU/L; ACE: 0.06 +/- 0.14 IU/L; p < 0.01). According to these results, BAR protects pulmonary endothelium and type II pneumocytes in the early phase after lung transplantation and might have consequences for lung tissue in the long term.
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PMID:Bronchial artery revascularization affects graft recovery after lung transplantation. 1179 Jun 58

Lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) activities were studied during corneal epithelial growth and differentiation in cell culture. LDH and G-6-PDH activities increased up to 60 and 150-fold, respectively, when corneal epithelial cells constituted a differentiated four to five layered epithelium; these increases showed a similar time-course to the expression of K3 keratin. Immunostaining experiments showed that in growing colonies, LDH staining is stronger in those cells that are K3 positive; in contrast, in confluent four to five layered epithelia LDH and K3 were located in all cell layers, similar to the pattern found in frozen sections from rabbit central cornea. During growth and differentiation, the LDH isoenzyme set from corneal epithelial cells did not change; and it was different from those observed in cultured conjunctival, esophageal and epidermal cells. The augment in LDH activity was due to a 25-fold increase in the LDH-H mRNA and a 12-fold augment in LDH-M mRNA. A computer-assisted search led to identify AP2 and Sp1 binding sites in the LDH and G-6-PDH promoters, suggesting that their expression might share common regulatory mechanisms with the regulation of the differentiation-linked keratins. It is proposed that LDH may be an early marker of corneal epithelial differentiation, and its isozyme pattern could be distinctive from other epithelial cell lineages.
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PMID:Differentiation-dependent increases in lactate dehydrogenase activity and isoenzyme expression in rabbit corneal epithelial cells. 1187 20


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