Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.3.99.3 (acyl-CoA dehydrogenase)
1,425 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relationships between the carnitine concentration and enzyme activities representative of different metabolic pathways, glycogenolysis, glycolysis, beta-oxidation of fatty acids, citric acid cycle, and respiratory chain were studied in skeletal muscle tissue from 18 volunteering subjects. In addition, the in vitro incorporation rates of glucose-carbon and palmitate-carbon into different metabolites, and the concentration of glycogen, triglycerides, and phospholipids were determined in the same tissue specimen. The carnitine concentration correlated positively and statistically significantly with the activities of 3-OH-acyl-CoA dehydrogenase and citrate synthase, with the incorporation rate of palmitate-carbon into CO2, and the incorporation rate of glucose-carbon into lactate in the muscle tissue. The results indicate a coupling between the concentration of carnitine and the capacity for long-chained fatty acid oxidation in human skeletal muscles.
...
PMID:Carnitine concentration in relation to enzyme activities and substrate utilization in human skeletal muscles. 13 18

The activities (Vmax) of hexokinase, glycogen phosphorylase, glucose-6-phosphate dehydrogenase, phosphofructokinase, lactate dehydrogenase, citrate synthase, cytochrome c oxidase, and 3-OH-acyl-CoA dehydrogenase in human skeletal muscles were compared with the in vitro utilization of glucose and palmitic acid assessed under optimal conditions. Statistically significant correlations between substrate fluxes and enzyme activities were found suggesting that the substrate incorporation rate in vitro in some way reflects the capacity of metabolic pathways. The incorporation rate of leucine into muscle proteins was also statistically significantly correlated to the RNA concentration in the muscle tissue. Glycolytic and glycogenolytic enzymes correlated significantly to each other and correlations were also found between aerobic enzymes supporting the validity of constant proportions between certain key enzymes in human skeletal muscles.
...
PMID:Incorporation rate of glucose carbon, palmitate carbon and leucine carbon into metabolites in relation to enzyme activities and RNA levels in human skeletal muscles. 17 28

The role of inherited metabolic defects in SIDS is controversial: some workers think that they may account for the cause of death in about 10% of cases. Many maintain that this is a gross overestimate, but it cannot be denied that the sudden onset and rapid deterioration known to occur in some metabolic disorders during the first year of life can mimic SIDS. This may remain undetected unless postmortem material is examined in specialist centres with individual metabolic disorders in mind. Defects in energy metabolism and the maintenance of glucose homeostasis frequently show this pattern of presentation precipitated by minor clinical infection. These disorders include the glycogen storage disorders, gluconeogenic enzyme defects, and the defects of fatty acid oxidation. Several reports have appeared since 1984 linking fatty acid oxidation defects with SIDS. Estimates of their prevalence vary, due partly to methodological heterogeneity and partly to the limited size of individual studies which have not permitted adequate statistical analysis. Nevertheless, the lack of adequate information has not precluded a great deal of debate. Over the past seven years a group in Sheffield has studied the occurrence of these defects in SIDS using three distinct approaches: retrospective analysis of SIDS cases, prospective analysis of SIDS cases, prospective analysis of urine obtained from siblings of SIDS cases during the first week of life. The result of these studies would suggest that the contribution to SIDS made by medium chain acyl CoA dehydrogenase deficiency may be in the region of 1%. Additional related metabolic disorders may account for a further as yet undefined small percentage. The eventual resolution of some of these uncertainties may be provided by harmonizing the results of existing studies and by DNA analysis of materials obtained at necropsy in SIDS cases.
...
PMID:Metabolic deficiencies and SIDS. 147 57

A case of severe hypoglycaemia precipitated by fasting in a child is described. As a result of the hypoglycaemia, the patient became brain damaged. The mechanism causing the hypoglycaemia was a defect in the fatty acid beta-oxidation enzyme, the connecting link acyl-CoA dehydrogenase. During a prolonged fast, fatty acids are not converted to acetyl-CoA and ketone bodies which participate in Kreb's cycle for production of energy to a sufficient extent. This result in non-ketotic hypoglycaemia with excretion of organic acids in the urine. As a rule, the symptoms occur for the first time during the first to second years of life in connection with common infectious diseases, with vomiting followed by clouding of consciousness and possibly coma, but the condition may also present with sudden unexpected death. Treatment consists of intravenous glucose. The diagnosis is established by testing the urine for hexanoylglycin and other substances and is confirmed by culture of skin fibroblasts and measurement of beta-oxidation activity. The disease is an autosomally recessive inherited condition. In families where there have been cases of unexplained hypoglycaemia and clouding of consciousness and cases of unexplained death in infancy or "near misses", all of the family members should be offered examination for the above mentioned enzyme deficiency.
...
PMID:[Severe hypoglycemia and clouding of consciousness caused by deficiency of the connecting link acyl CoA dehydrogenase]. 200 Jun 54

Subjective fatigue was quantified before and 20 days after uncomplicated elective abdominal surgery in 12 patients and compared with changes in heart rate, enzyme activities and skeletal muscle substrates before and after bicycle exercise for 10 min at 65 per cent of patients' preoperative maximum work capacity. Fatigue increased from a mean(s.e.m.) preoperative level of 2.5(0.5) arbitrary units to 4.6(0.5) on postoperative day 20 (P less than 0.01). Body-weight, triceps skinfold thickness and arm circumference decreased postoperatively (P less than 0.02). Postoperative values of muscle enzyme activities indicative of oxidative phosphorylation capacity (citrate synthase and 3-OH-acyl coenzyme A dehydrogenase) were lower than preoperative values (P less than 0.05). Lactate dehydrogenase was unaltered and resting values of muscle glycogen and adenosine triphosphate were higher after operation (P less than 0.05). In response to exercise, heart rate, muscle glucose, glucose-6-phosphate and lactate increased (P less than 0.05), while muscle glycogen and creatine phosphate decreased (P less than 0.05). Increase in postoperative fatigue correlated with the increase in heart rate (P less than 0.05), while no significant correlations were found between fatigue and muscle parameters. Our results suggest that lack of exercise and malnutrition may be of importance in the decrease in work capacity and in fatigue after operation.
...
PMID:Skeletal muscle enzyme activities and metabolic substrates during exercise in patients with postoperative fatigue. 232 98

Medium-chain acyl-CoA dehydrogenase deficiency is a recently described inborn error of metabolism characterized by episodes of coma and hypoketotic hypoglycaemia in response to prolonged fasting. Secondary carnitine deficiency has been documented in these patients as well as the excretion in the urine of medium-chain-length acyl carnitine esters, such as octanoylcarnitine. Based on the potential toxicity of medium-chain fatty acid metabolites and the beneficial responses of patients with other inborn errors of metabolism and secondary carnitine deficiency, oral carnitine has been proposed as treatment for children with medium-chain acyl-CoA dehydrogenase deficiency. We report the results of carefully monitored fasting challenges of an infant with this deficiency both before and after 3 months of oral carnitine therapy. Carnitine supplementation failed to prevent lethargy, vomiting, hypoglycaemia and accumulation of free fatty acids in response to fasting despite normalization of plasma carnitine levels and a marked increase in urinary excretion of acyl-carnitine esters. Potentially toxic medium-chain fatty acids accumulated in the plasma in spite of therapy. Based on this study of one patient, we stress that avoidance of fasting and prompt institution of glucose supplementation in situations when oral intake is interrupted remain the mainstays of therapy for medium-chain acyl-CoA dehydrogenase deficient patients.
...
PMID:Medium-chain acyl-CoA dehydrogenase deficiency: metabolic effects and therapeutic efficacy of long-term L-carnitine supplementation. 250 71

The effects of methylenecyclopropylglycine (MCPG), the lower homologue of hypoglycin A, on starved rats are described. Upon oral ingestion of MCPG (43 mg/kg), a 50% decrease in blood glucose compared with controls was observed after 4 h. The plasma concentrations of lactate and non-esterified fatty acids were substantially increased during this period. The activity of general acyl-CoA dehydrogenase from isolated rat liver mitochondria was not significantly changed. By contrast, the activity of 2-methyl-(branched-chain)-acyl-CoA dehydrogenase decreased by over 80%. The enzyme activity of enoyl-CoA hydratase (crotonase) from pig kidneys decreased by 80% on incubation with the hypothetically toxic metabolite of MCPG, methylenecyclopropylformyl-CoA. These results suggest that the inhibition spectrum of MCPG is quite different from that of hypoglycin A and that similar physiological effects might result from inhibition of different enzymes of beta-oxidation, e.g. hypoglycaemia and lacticacidemia. Accumulation of medium-chain acyl-CoA thioesters is probably at the origin of disturbances in pyruvate metabolism.
...
PMID:Mechanism of hypoglycaemic action of methylenecyclopropylglycine. 273 May 93

Fatty acid degradation was investigated in Caulobacter crescentus, a bacterium that exhibits membrane-mediated differentiation events. Two strains of C. crescentus were shown to utilize oleic acid as sole carbon source. Five enzymes of the fatty acid beta-oxidation pathway, acyl-coenzyme A (CoA) synthase, crotonase, thiolase, beta-hydroxyacyl-CoA dehydrogenase, and acyl-CoA dehydrogenase, were identified. The activities of these enzymes were significantly higher in C. crescentus than the fully induced levels observed in Escherichia coli. Growth in glucose or glucose plus oleic acid decreased fatty acid uptake and lowered the specific activity of the enzymes involved in beta-oxidation by 2- to 3-fold, in contrast to the 50-fold glucose repression found in E. coli. The mild glucose repression of the acyl-CoA synthase was reversed by exogenous dibutyryl cyclic AMP. Acyl-CoA synthase activity was shown to be the same in oleic acid-grown cells and in cells grown in the presence of succinate, a carbon source not affected by catabolite repression. Thus, fatty acid degradation by the beta-oxidation pathway is constitutive in C. crescentus and is only mildly affected by growth in the presence of glucose. Tn5 insertion mutants unable to form colonies when oleic acid was the sole carbon source were isolated. However, these mutants efficiently transported fatty acids and had beta-oxidation enzyme levels comparable with that of the wild type. Our inability to obtain fatty acid degradation mutants after a wide search, coupled with the high constitutive levels of the beta-oxidation enzymes, suggest that fatty acid turnover, as has proven to be the case fatty acid biosynthesis, might play an essential role in membrane biogenesis and cell cycle events in C. crescentus.
...
PMID:Fatty acid degradation in Caulobacter crescentus. 287 91

At the time of acute presentation, children with carnitine deficiency may have increased free fatty acid concentrations and hypoglycemia. However, whether carnitine replacement affects the plasma concentration of these substrates remains to be determined. Therefore, to evaluate the effect of carnitine replacement on plasma substrate and hormone concentrations, five children with carnitine deficiency (two idiopathic, two secondary to long-chain acyl coenzyme A dehydrogenase deficiency, one secondary to isovaleric acidemia) were fasted overnight before and after treatment with oral carnitine (80 +/- 7 mg.kg-1.day-1). During carnitine supplementation, plasma total carnitine (19 +/- 4 versus 45 +/- 6 nmol/ml, pretreatment versus treatment, respectively) and free carnitine (11 +/- 3 versus 31 +/- 6 nmol/ml), as well as red blood cell total carnitine (0.057 +/- 0.019 versus 0.130 +/- 0.019 nmol/mg of hemoglobin) increased (p less than 0.05). Fasting plasma glucose (83 +/- 4 versus 85 +/- 3 mg/dl) and ketone body (0.54 +/- 0.18 and 0.56 +/- 0.20 mM) concentrations did not change with carnitine supplementation, but plasma free fatty acids (1.28 +/- 0.32 versus 0.77 +/- 0.07 mM) decreased (p less than 0.05). No differences in fasting insulin, growth hormone, or cortisol concentrations were observed. Urinary excretion of free carnitine (0.1 +/- 0.0 versus 2.4 +/- 0.7 mumol/mg creatinine), total carnitine (0.3 +/- 0.1 versus 3.4 +/- 0.9 mumol/mg creatinine) and acyl carnitine (0.2 +/- 0.1 versus 0.9 +/- 0.3 mumol/mg creatinine) increased (p less than 0.05) with carnitine supplementation. The decreased plasma free fatty acid concentrations with carnitine supplementation may be due to more efficient fatty acid oxidation and/or increased urinary excretion of fatty acids as acylcarnitines.
...
PMID:Decreased fasting free fatty acids with L-carnitine in children with carnitine deficiency. 329 Aug 28

Seven middle-aged men with manifest type II diabetes mellitus underwent an endurance training programme for 10-15 weeks. The maximal aerobic capacity, as well as the endurance capacity, was improved by 10% (p less than 0.05). The intramuscular glycogen store increased by more than 80% (p less than 0.05) from 350 mumol/g dw (dry weight), and the activities of citrate synthase and 3-hydroxy-acyl-CoA dehydrogenase increased by more than 50% (p less than 0.05) and 30% (p less than 0.05). The activity of glycogen synthase was decreased by approximately 20% (p less than 0.05), whereas lactate dehydrogenase remained unchanged. Capillaries/fibre and fibre area increased by more than 50% (p less than 0.05) and 30% (p less than 0.05) leaving the area of supply constant. Training did not influence fasting blood lipids and glucose, glycosylated hemoglobin, oral glucose tolerance, and insulin response to an oral glucose load measured 72 hours post-exercise. It is concluded that patients with manifest type II diabetes, as normoglycaemic individuals, adapt to physical training. However, no persistent effect on glucohomeostasis and lipaemia is produced by short-term training in the diabetic patients.
...
PMID:Skeletal muscle adaptations to physical training in type II (non-insulin-dependent) diabetes mellitus. 336 17


1 2 3 4 5 6 7 8 9 10 Next >>

---