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metabolic difference of glycogenolysis, glycolysis and alpha-glycerophosphate oxidation between the three muscles was no longer maintained.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

Male 13-lined ground squirrels induced to emerge from hibernation resumed feeding and gained weight. The weight gain was supported by increases in the levels of glucose 6-phosphate dehydrogenase, L-alanine aminotransferase and carnitine acetyltransferase in the liver. Maturation of the testis occurred in a period of about 16 days spanning the time of induced arousal. The testes of hibernating males were characterized by higher levels of L-alanine aminotransferase, glucose 6-phosphate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase than the testes of aroused males. Hexokinase, carnitine acetyltransferase and citrate synthase levels were similar in the testes of hibernating and aroused males. 3-Hydroxyacyl-CoA dehydrogenase was more active and L-alanine aminotransferase less active in ground squirrel sperm than in rat sperm.
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PMID:Changes in enzyme levels in the testis and liver of the 13-lined ground squirrel (spermophilus tridecemlineatus) at the time of arousal from hibernation. 7 Oct 81

Differences of metabolic qualities and capacities among organs and tissues of perinatal rabbits were investigated. A suitable alternative for the measurement of substrate utilization of single organs seems to be the total amount of certain key enzyme activities calculated for whole organs. The immediate perinatal period is the object of this study with adult animals serving as a reference. We have selected the phosphofructokinase activity to represent the upper segment of glycolytic reactions, 3-hydroxyacyl-CoA dehydrogenase as a key enzyme for beta-oxidation of fatty acids and citrate synthase activity to represent the Krebs cycle activity. In fetal, newborn, and adult rabbits we analyzed liver, kidneys, heart, lung, brain, brown and white adipose tissue, stomach and intestines, skin, a representative sample of skeletal muscles, and of bones. The organ weight distribution, total amount of protein, and DNA was determined for the same ten organs. The share each organ contributes to the total body key enzyme activity shows the importance of each metabolic capacity which is represented by the three enzymes. In perinatal adipose tissue the very high potential for energy production through utilization of Krebs cycle reactions is striking. The same tissue has a high capacity to oxidize fatty acids. The skeletal muscle represents the biggest capacity of glycolytic reactions in all age groups. After birth the metabolic profile of the whole organism shows a marked and steep increase of glycolytic capacity, whereas the capacity to oxidize fatty acids decreases slowly.
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PMID:Perinatal changes of interorgan differences in cell metabolism. 12 90

The intracellular location of pyruvate carboxylase (EC 6.4.1.1), citrate synthase (EC 4.1.3.7) and 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35) in rat mammary gland was investigated by using a fractional-extraction technique. The results indicate a mitochondrial location for all three enzymes.
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PMID:The intracellular location of pyruvate carboxylase, citrate synthase and 3-hydroxyacyl-CoA dehydrogenase in lactating rat mammary gland. 64 21

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

Forty-five Large White barrows were injected daily i.m. with either excipient from 30 to 100 kg BW (CTRL), excipient from 30 to 60 and porcine somatotropin (pST; 100 micrograms/kg BW) from 60 to 100 kg BW (pST-60), or pST (100 micrograms/kg BW) from 30 to 100 kg BW (pST-30). Somatotropin accelerated overall growth rate (+4 and +9% for pST-60 and pST-30, respectively), increased longissimus (+10.3 and +14.7%) and semitendinosus (+17 and +13%) muscle weights, and decreased backfat (-49 and -58%) and leaf fat (-49 and -53%) weights. The administration of pST resulted in a similar increase in muscle fiber size for all fiber types in both longissimus (LM) and semispinalis (SS) muscles (+21%). Somatotropin had otherwise little effect on muscle fiber types and biochemical traits of LM, whereas dramatic changes were observed in SS. The relative area occupied by Type IIB fibers was increased (+22 and +29%) and that of Type I fibers was decreased (-10 and -15%). In pST-30 animals, myosin ATPase activity (+15%) and native myosin fast isoform proportion (+10%) were augmented, and energy metabolism was more glycolytic (lactate dehydrogenase: +25%) and less oxidative (citrate synthase: -13%; beta-hydroxyacyl-CoA dehydrogenase: -21%). Compared to CTRL animals, administration of pST increased muscle water concentration (LM: +.8 and +1.1%: SS: +3.3 and +3.3%) and decreased intramuscular fat (LM: -29 and -27%; SS: -39 and -50%). The pH measured 45 min and 24 h postmortem, glycogen content, reflectance, and index of light diffusion were mostly not affected by pST treatment. In conclusion, pST had a very favorable effect on growth performance without any important effect on meat quality traits except for the reduction in intramuscular lipid content. The results indicated that the effects of pST on muscular histochemical and biochemical characteristics were different in LM and SS muscles.
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PMID:Performance, plasma hormones, histochemical and biochemical muscle traits, and meat quality of pigs administered exogenous somatotropin between 30 or 60 kilograms and 100 kilograms body weight. 145

We examined the oxidative and antioxidant enzyme activities in respiratory and locomotor muscles in response to endurance training in young and aging rats. Young adult (4-mo-old) and old (24-mo-old) female Fischer 344 rats were divided into four groups: 1) young trained (n = 12), 2) young untrained (n = 12), 3) old trained (n = 10), and 4) old untrained (n = 6). Both young and old endurance-trained animals performed the same training protocol during 10 wk of continuous treadmill exercise (60 min/day, 5 days/wk). Compared with young untrained animals, the young trained group had significantly elevated (P less than 0.05) activities of 3-hydroxyacyl-CoA dehydrogenase (HADH), glutathione peroxidase (GPX), and citrate synthase (CS) in both the costal diaphragm and the plantaris muscle. In contrast, training had no influence (P greater than 0.05) on the activity of lactate dehydrogenase within the costal diaphragm in young animals. In the aging animals, training did not alter (P greater than 0.05) activities of CS, HADH, GPX, or lactate dehydrogenase in the costal diaphragm but significantly (P less than 0.05) increased CS, HADH, and GPX activities in the plantaris muscle. Furthermore, training resulted in higher activities of CS and HADH in the intercostal muscles in the old trained than in the old untrained animals. Finally, activities of CS, HADH, and GPX were significantly (P less than 0.05) lower in the plantaris in the old untrained than in the young untrained animals; however, CS, HADH, and GPX activities were greater (P less than 0.05) in the costal diaphragm in the old sedentary than in the young untrained animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aging and respiratory muscle metabolic plasticity: effects of endurance training. 156 62

To examine the effects of aging on human skeletal muscle, 10 men and 10 women, 64 +/- 1 yr old (Mean +/- SE), and 10 men and 10 women, 24 +/- 1 yr old, were studied. All subjects were sedentary nonsmokers who were carefully screened for latent cardiovascular, metabolic, or musculoskeletal disease. Needle biopsy samples were obtained from the lateral gastrocnemius muscle and examined using histochemical and biochemical techniques. The percentage of Type I, Type IIa, and Type IIb fibers did not differ with age. However, Type I fibers occupied a larger percent of total muscle area in the older men and women (60.6 +/- 2.6 vs 53.6 +/- 2.0%; p less than .05), because Type IIa and Type IIb fibers were 13-31% smaller (p less than .001) in these subjects. Muscle capillarization and mitochondrial enzyme (i.e., succinate dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA dehydrogenase) activities were also approximately 25% lower (p less than .001-.05) in the old subjects. Although it is difficult to determine whether these differences are due to aging itself or are simply due to inactivity, these structural and biochemical changes probably contribute to the decreases in muscle mass, strength, and endurance often observed in healthy but sedentary older men and women.
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PMID:Histochemical and enzymatic comparison of the gastrocnemius muscle of young and elderly men and women. 157 81

Previous studies of endurance exercise training in older men and women generally have found only minimal skeletal muscle adaptations to training. To evaluate the possibility that this may have been due to an inadequate training stimulus, we studied 23 healthy older (64 +/- 3 yr) men and women before and after they had trained by walking/jogging at 80% of maximal heart rate for 45 min/day 4 days/wk for 9-12 mo. This training program resulted in a 23% increase in maximal O2 consumption. Needle biopsy samples of the lateral gastrocnemius muscle were obtained before and after training and analyzed for selected histochemical and enzymatic characteristics. The percentage of type I muscle fibers did not change with training. The percentage of type IIb fibers, however, decreased from 19.1 +/- 9.1 to 15.1 +/- 8.1% (P less than 0.001), whereas the percentage of type IIa fibers increased from 22.1 +/- 7.7 to 29.6 +/- 9.1% (P less than 0.05). Training also induced increases in the cross-sectional area of both type I (12%; P less than 0.001) and type IIa fibers (10%; P less than 0.05). Capillary density increased from 257 +/- 43 capillaries/mm2 before training to 310 +/- 48 capillaries/mm2 after training (P less than 0.001) because of increases in the capillary-to-fiber ratio and in the number of capillaries in contact with each fiber. Lactate dehydrogenase activity decreased by 21% (P less than 0.001), whereas the activities of the mitochondrial enzymes succinate dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA dehydrogenase increased by 24-55% in response to training (P less than 0.001-0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Skeletal muscle adaptations to endurance training in 60- to 70-yr-old men and women. 160 86


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