Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Representative enzyme activities of energy supplying metabolism were measured in muscle specimens of brachial biceps, deltoid or anterior tibial muscle of patients with affections of the peripheral nerves. Simultaneously performed measurements of the same enzyme activities in the contralateral normal muscles served as a control. 5 patients suffered from a lesion of the brachial plexus, 7 patients had a paralysis of the axillary nerve, and 8 patients had a peroneal paralysis. In all denervated muscles no electrophysiological signs of reinnervation were present. The activities of glycogen phosphorylase, triosephosphate dehydrogenase, lactate dehydrogenase and alpha-glycerophosphate dehydrogenase were found to be highest in the normal brachial biceps muscle. Lower activities were measured in the normal deltoid and anterior tibial muscle. The oxidative enzymes, 3-hydroxyacyl-CoA dehydrogenase and citrate synthase as well as hexokinase, showed no significant difference from the levels of the control. It is suggested that a probable factor determining the differences of the enzyme activities of glycogenolysis, glycolysis and alpha-glycerophosphate oxidation between brachial biceps, deltoid and anterior tibial muscle, might be the pattern of impulse activity in the motor nerves of these muscles. The enzyme activities of glycogen phosphorylase, triosephosphate dehydrogenase, lactate dehydrogenase and alpha-glycerophosphate dehydrogenase, decreased rapidly during the first 2 months after denervation in the brachial biceps, deltoid and anterior tibial muscle, whereas the decrease was slight during the following months. The activities of the oxidative enzymes (3-hydroxyacyl-CoA dehydrogenase and citrate synthase) showed no significant change after denervation. The metabolic difference of glycogenolysis, glycolysis and alpha-glycerophosphate oxidation between the three muscles was no longer maintained. The possible causes of the deeply decreased enzyme activities of glycogenolysis, glycolysis and alpha-glycerophosphate oxidation, as well as the causes of the unchanged oxidative enzyme activities and of the increased hexokinase activity after denervation in the human brachial biceps, deltoid and anterior tibial muscle, are discussed.
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PMID:[Representative enzymes of energy supplying metabolism in the normal and denervated human brachial biceps, deltoid and anterior tibial muscles (author's transl)]. 5 9

8 male patients (age 65-82 years) suffering from bacterial pneumonia or erysipelas were subjected to skeletal muscle biopsies. Significantly lower activities of lactate dehydrogenase (LDH) and glyceraldehyde-3-phosphate dehydrogenase (TPD) of skeletal muscle were recorded in the acute phase of the illness as compared to after the end of the convalescent phase. For citrate synthetase (CS) a similar although non-significant tendency was observed, while cytochrome c oxidase (CYTOX) was not altered by infection. Similar results have been reported in young patients with viral and mycoplasma infections. In the old patients the activity of LDH was approximately half of that found in the young patients (and in young controls confined to bed) on all occasions of measurement.
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PMID:Human skeletal muscle in bacterial infection: enzyme activities and their relationship to age. 19 74

1. The changes with the time of the activities of some energy-supplying enzymes and of the hydrolytic enzyme, acid phosphatase, were studied over 2 weeks of complete ischaemia, produced in the rat soleus muscle by section of the abdominal aorta and terminal devascularization, leaving nerve and tendon intact. 2. Activities of glycolytic enzymes, oxidative enzymes, hexokinase and acid phosphatase are affected in a different manner. Activities of the glycolytic enzymes, lactate dehydrogenase, triosephosphate dehydrogenase and glycerolphosphate dehydrogenase, are lowest on the 1st day and increase thereafter. The first two reach the control values again on the 4th and 14th day, respectively, while glycerolphosphate dehydrogenase reaches about 50% of the control value on the 14th day. The maximum decrease in activity of the oxidative enzymes, citrate synthase, beta-hydroxyacyl-CoA-dehydrogenase and malate dehydrogenase occurs later (4th day); thereafter their activity returns slowly to control values, but does not reach them even on the 14th day. Hexokinase activity is slightly decreased on the 1st day; then it increased and reached on the 7th day twice the control value. Thus on the 1st day the activity of the enzymes of aerobic metabolism prevail, and on the 4th day those of anaerobic carbohydrate (glucose) metabolism; the recovery of enzyme activity of aerobic oxidation occurs later. 3. Acid phosphatase activity increased from the 2nd day onwards, reaching up to 3 times the control value on the 4th day and still twice that value on the 14th day. This agrees well with the histochemical picture of acid phosphatase. 4. Histochemical changes of alkaline phosphatase activity reveal destruction of capillary endothelial cells during the first few days after operation and their later proliferation from the periphery, correlating with the loss and recovery of oxidative enzyme activity.
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PMID:Effects of ischaemia on enzyme-activities in the soleus muscle of the rat. 57 Nov 16

In biopsy samples of the lateral part of the quadriceps femoris muscle of 6 obese diabetic male patients and of 11 obese males with a normal glucose tolerance, the activities of 7 enzymes of energy metabolism were estimated: hexokinase, cytoplasmic glycerol-3-phosphate: NAD dehydrogenase, triosephosphate dehydrogenase, lactate dehydrogenase, citrate synthase, malate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase. The obese diabetic male patients exhibited decreased activities of enzymes of carbohydrate breakdown and cytoplasmic NAD regeneration. Enzymes connected functionally with aerobic metabolism were less affected. The unchanged activity of 3-hydroxyacyl-CoA dehydrogenase points to an increased role of fatty acid catabolism in the muscle.
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PMID:Enzyme activities in quadriceps femoris muscle of obese diabetic male patients. 90 76

1. In 3 groups of men, differing as to the amount and intensity of physical training loads, increasing in the order "sedentary": "sporting": "athletic", enzyme activities were estimated in biopsy samples of m. quadriceps femoris (vastus lateralis). The enzymes were: Hexokinase (HK), NAD: glycerol-3-phosphate dehydrogenase (GPDH), triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), citrate synthase (CS), NAD: malate dehydrogenase (MDH), and 3-hydroxyacyl-CoA dehydrogenase (HOADH). Indicators of laboratory performance and whole-body metabolic capacities (maximal oxygen consumption etc.) were estimated in the "sporting" and "athletic" groups. 2. In the 2 latter groups, distinguished by greater physical activity, the atypical enzyme activity pattern, remarkable by a low activity of LDH and high relative activities of GPDH and HK, as reported earlier in a sedentary group (Bass et al., 1975a), disappeared. The possibility of the atypical low LDH enzyme activity pattern as resulting from lack of bodily exertion is discussed. 3. The moderately trained "sporting" group distinguishes itself from the "sedentary" one mainly by a higher activity of LDH and by lower activities of GPDH and MDH. In the intensively trained "athletic" group, enzymes connected to aerobic oxidation (MDH, CS, HOADH) and GPDH also show higher activities than in the "sporting" group. The difference between the two more active groups is further borne out by a higher maximum oxygen uptake and carbon dioxide release of the well-trained "athletic" group. This difference of enzyme activity pattern may not be confined to the quadriceps femoris muscle.
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PMID:Enzyme activity patterns of energy supplying metabolism in the quadriceps femoris muscle (vastus lateralis): sedentary men and physically active men of different performance levels. 94 91

1. The following enzyme activities were estimated in needle-biopsy samples of the lateral part of the human quadriceps femoris muscle: triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), NAD : glycerol-3-phosphate dehydrogenase (GPDH), hexokinase (HK), NAD: malate dehydrogenase (MDH), citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase. 2. Although the enzyme activities in muscles of women were lesser than in those of men, no difference was found in the calculated enzyme activity ratios. There is thus no sex-dependent metabolic type-differentiation in this muscle. 3. The human quadriceps femoris is a low-activity muscle, in comparison with muscles of homoiotherm laboratory animals. The enzyme activity ratio of TPDH to CS, characterizing the glycolytic pyruvate formation to aerobic oxidative capacities, shows this muscle to be of an intermediate type in this respect, similarly as the extensor digitorum longus of the rat. The relatively very high capacity of glucose phosphorylation (HK), the high aerobic regeneration of cytoplasmic dehydrogenated NAD (GPDH) and the very low anaerobic regeneration (LDH), show the unusually high proportion of carbohydrates (glucose) which can be broken down aerobically.
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PMID:M. Quadriceps femoris of man, a muscle with an unusual enzyme activity pattern of energy supplying metabolism in mammals. 116 80

1. In biopsy samples of the lateral part of m. quadriceps femoris of 49 obese and 14 lean persons the activities of the following enzymes were investigated: triosephosphate dehydrogenase (TPDH), glycerolphosphate: nad dehydrogenase (GPDH), lactate dehydrogenase (LDH), hexokinase (HK), malate: NAD dehydrogenase (MDH), citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase (HOADH). 2. The muscles of obese had an increased activity ratio of TPDH to CS and to HK, respectively, caused in muscles of female obese subjects by an increase of TPDH activity, in those of obese men rather by a decrease of CS and HK activities. 3. Cluster analysis brough to light the existence of three major groups. Group 1 (low activity-low LDH group), consisting of muscles of female obese subjects only, exhibited low activities of all enzymes investigated, that of LDH being so low as to possibly induce a serious deficiency of anerobic metabolism under working conditions. Group 2 (medium enzyme activity group) was characterized by medium enzyme activities, similar to that of lean controls (included in this group). This consisted of subjects of both sex. Group 3 (high enzyme activity group) consisted of obese of both sex. It was distinguished by high enzyme activities, especially of LDH. It is suggested that the groups of similar enzyme activity patterns might reflect different stages, types and/or genesis of obesity.
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PMID:Metabolic changes in the quadriceps femoris muscle of obese people. Enzyme activity patterns of energy-supplying metabolism. 123 24

Metabolic adaptations were studied in papillary muscle from 18 patients undergoing open-heart surgery for mitral valve disease. Analyses were made of myoglobin (MG), the enzymes lactate dehydrogenase (LD) with its isoenzymes, glyceraldehyde phosphate dehydrogenase (GAPDH), phosphofructokinase (PFK), citrate synthase (CS) and creatine kinase (CK) with its isoenzymes MB (CK-MB) and mitochondrial CK (CK-MIT). Myocardial function was assessed with left ventricular angiography. Positive and significant correlations were found between enzymes of oxidative metabolism, i.e. CS on the one hand and MG (r = 0.76), LD1 (r = 0.68), CK-MIT (r = 0.86) and CK-MB (r = 0.65) on the other. Indicators of glycolysis--PFK, GAPDH and LD3--varied independently of CS. LD3% was directly related to GAPDH (r = 0.66). In a sub-group of 12 patients with isolated mitral regurgitation due to myxomatous valve degeneration, LD3% rose (r = 0.72) with increasing myocardial derangement which, however, showed no relationship with any other marker. Thus the capacities of oxidative and glycolytic pathways did not co-vary. Volume load appeared not to affect oxidative capacity, while the anaerobic fraction of glycolysis was increased.
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PMID:Key enzymes of myocardial energy metabolism in papillary muscle of patients with mitral valve disease--relation to left ventricular function. 252 75

The early stages of insulin-dependent diabetes mellitus are characterized by a selective inability to secrete insulin in response to glucose, coupled to a better response to nonnutrient secretagogues. The deficient glucose response may be a result of the autoimmune process directed toward the beta-cells. Interleukin-1 (IL-1) has been suggested to be one possible mediator of immunological damage of the beta-cells. In the present study we characterized the sensitivity of beta-cells to different secretagogues after human recombinant IL-1 beta (rIL-1 beta) exposure. Furthermore, experiments were performed to clarify the biochemical mechanisms behind the defective insulin response observed in these islets. Rat pancreatic islets were isolated and kept in tissue culture (medium RPMI-1640 plus 10% calf serum) for 5 days. The islets were subsequently exposed to 60 pM human recombinant IL-1 beta during 48 h in the same culture conditions as above and examined immediately after IL-1 exposure. The rIL-1 beta-treated islets showed a marked reduction of glucose-stimulated insulin release. Stimulation with arginine plus different glucose concentrations, and leucine plus glutamine partially counteracted the rIL-1 beta-induced reduction of insulin release. The activities of the glycolytic enzymes hexokinase, glucokinase, and glyceraldehyde 3-phosphate dehydrogenase, were similar in control and IL-1-exposed islets. Treatment with IL-1 also did not impair the activities of NADH+- and NADPH+-dependent glutamate dehydrogenase, glutamate-aspartate transaminase, glutamate-alanine transaminase, citrate synthase, and NAD+-linked isocitrate dehydrogenase. The oxidation of D-[6-14C]glucose and L-[U-14C]leucine were decreased by 50% in IL-1-treated islets. Furthermore, there was a significant decrease in the ratios of [2-14C]pyruvate oxidation/[1-14C]pyruvate decarboxylation and L-[U-14C]leucine oxidation/L-[1-14C]leucine decarboxylation, indicating that IL-1 decreases the proportion of generated acetyl-coenzyme-A residues undergoing oxidation. However, in the presence of IL-1 there was a significant increase in L-[U-14C]glutamate oxidation. These combined observations suggest that exposure to IL-1 induces a preferential decrease in glucose-mediated insulin release and mitochondrial glucose metabolism. This mitochondrial dysfunction seems to reflect an impairment in proximal steps of the Krebs cycle. It is conceivable that the IL-1-induced suppression and shift in islet metabolism can be an explanation for the beta-cell insensitivity to glucose observed in the early phases of human and experimental insulin-dependent diabetes mellitus.
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PMID:Differential sensitivity to beta-cell secretagogues in cultured rat pancreatic islets exposed to human interleukin-1 beta. 266 6

A method for a 50-60-fold purification of a cysteine proteinase from trophozoites of Entamoeba histolytica using 35-80% ammonium sulphate fractionation, gel chromatography on Sephadex G-75, and preparative isoelectric focusing is described. The enzyme was examined for its proteolytic potencies towards native enzyme substrates. The amebic proteinase directly inactivates aldolase and glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle as well as glucose-6-phosphate dehydrogenase from yeast. The inactivation of citrate synthase from porcine heart proceeds rather slowly, whereas malate dehydrogenase from porcine heart is not affected by the amebic proteinase under the condition used. With the exception of aldolase all inactivated enzyme substrates have been cleaved by limited proteolyses yielding major cleavage products. The inactivation of aldolase probably functions by the release of a small segment from a terminus being essential for aldolase activity.
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PMID:Cysteine proteinase of Entamoeba histolytica. I. Partial purification and action on different enzymes. 287 Apr 30


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