scholarly journals Comparative studies on 3-oxo acid coenzyme A transferase from various rat tissues

1974 ◽  
Vol 142 (3) ◽  
pp. 619-627 ◽  
Author(s):  
Allan Fenselau ◽  
Kathleen Wallis
Keyword(s):  
Citrate Synthase ◽  
Ketone Bodies ◽  
Rat Kidney ◽  
Gel Filtration ◽  
Close Correlation ◽  
Rat Tissues ◽  
Transferase Activity ◽  
Marker Enzyme ◽  
Coa Transferase ◽  
Mitochondrial Fractions

1. Tissue activities, intracellular distribution as well as selected kinetic and molecular properties of succinyl-CoA–3-oxo acid CoA transferase (EC 2.8.3.5), which is an initiator of ketone body usage, were examined in rat kidney, heart, brain, skeletal muscle and liver. 2. The activities of the transferase in these tissues are similar to reported values and are somewhat affected by the homogenization medium. Higher recoveries of activity are obtained when a phosphate buffer is used during the homogenization; Tris solutions containing sucrose and mannitol lead to only slightly lower recoveries, but can be used in studies to determine the subcellular localization of the transferase activity. 3. A close correlation was observed between the relative activities of citrate synthase (a mitochondrial marker enzyme) and CoA transferase in the cytoplasmic, particulate and mitochondrial fractions from the five tissues. 4. The Km values for acetoacetate (measured in two different ways), the ratio of Vmax. values for the two enzyme-catalysed half-reactions, and succinate product inhibition are quite similar for the enzyme from each tissue. 5. The enzymes are also similar in molecular weight (with an approx. mol.wt. of 100000 as determined by gel filtration). All show an active band in isoelectric-focusing studies with pI 7.6, except for the enzyme from heart (pI 6.8). 6. The results demonstrate a mitochondrial origin for CoA transferase in these rat tissues and support the proposition that CoA transferase is a ketolytic enzyme, i.e. an enzyme uniquely involved in the complete oxidation of ketone bodies. The structural and functional similarities of these transferases suggest that factors other than differences in Km values account for differences in the utilization of ketone bodies by various tissues.

scholarly journals Cloning of rat brain succinyl-CoA:3-oxoacid CoA-transferase cDNA. Regulation of the mRNA in different rat tissues and during brain development

1987 ◽  
Vol 248 (3) ◽  
pp. 853-857 ◽  
Author(s):  
M K Ganapathi ◽  
M Kwon ◽  
P M Haney ◽  
C McTiernan ◽  
A A Javed ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Rat Brain ◽  
Ketone Bodies ◽  
Rat Kidney ◽  
Relative Rate ◽  
Cdna Clones ◽  
Rat Tissues ◽  
Transferase Activity ◽  
Coa Transferase ◽  
Old Rats

3-Oxoacid CoA-transferase, which catalyses the first committed step in the oxidation of ketone bodies, is uniquely regulated in developing rat brain. Changes in 3-oxoacid CoA-transferase activity in rat brain during the postnatal period are due to changes in the relative rate of synthesis of the enzyme. To study the regulation of this enzyme, we identified, with a specific polyclonal rabbit anti-(rat 3-oxoacid CoA-transferase), two positive cDNA clones (approx. 800 bp) in a lambda gtll expression library, constructed from poly(A)+ RNA from brains of 12-day-old rats. One of these clones (lambda CoA3) was subcloned into M13mp18 and subjected to further characterization. Labelled single-stranded probes prepared by primer extension of the M13mp18 recombinant hybridized to a 3.6 kb mRNA. Rat brain mRNA enriched by polysome immunoadsorption for a single protein of size 60 kDa which corresponds to the precursor form of 3-oxoacid CoA-transferase was also found to be similarly enriched for the hybridizable 3.6 kb mRNA complementary to lambda CoA3. Affinity-selected antibody to the lambda CoA3 fusion protein inhibited 3-oxoacid CoA-transferase activity present in rat brain mitochondrial extracts. The 3.6 kb mRNA for 3-oxoacid CoA-transferase was present in relative abundance in rat kidney and heart, to a lesser extent in suckling brain and mammary gland and negligible in the liver. The specific mRNA was also found to be 3-fold more abundant in the brain from 12-day-old rats as compared with 18-day-old foetuses and adult rats, corresponding to the enzyme activity and relative rate of synthesis profile during development. These data suggest that 3-oxoacid CoA-transferase enzyme activity is regulated at a pretranslational level.

Effect of acute and chronic temperature transition on enzymes of cardiac metabolism in white perch (Morone americana), yellow perch (Perca flavescens), and smallmouth bass (Micropterus dolomieui)

1991 ◽  
Vol 69 (1) ◽  
pp. 258-262 ◽  
Author(s):  
Dawn H. Sephton ◽  
William R. Driedzic
Keyword(s):  
Yellow Perch ◽  
Citrate Synthase ◽  
White Perch ◽  
Perca Flavescens ◽  
Smallmouth Bass ◽  
Transferase Activity ◽  
Morone Americana ◽  
Coa Transferase ◽  
Micropterus Dolomieui ◽  
The Impact

White perch (Morone americana), yellow perch (Perca flavescens), and smallmouth bass (Micropterus dolomieui) were acclimated to 5 and 20 °C. There was an increase in ventricle mass relative to body mass in smallmouth bass only following acclimation to 5° C. Maximal in vitro activities of hexokinase, citrate synthase, carnitine acyl CoA transferase (with palmitoyl CoA, palmitoleoyl CoA, and oleoyl CoA as substrates), and total ATPase were assessed in crude heart homogenates. Tissues removed from warm-acclimated animals were tested at 20 and 5 °C; tissues removed from cold-acclimated animals were assessed at 5 °C. Acute temperature transitions were associated with decreases in the activities of hexokinase (Q10 ≈ 1.8), citrate synthase (Q10 ≈ 1.4), and ATPase (Q10 ≈ 1.7). The impact of temperature on carnitine acyl CoA transferases was generally less severe. This suggests that maximal fatty acid oxidation is conserved better than glucose oxidation during a warm to cold transition. Maximal enzyme activities were generally unaffected by the acclimation regime, with the exception of that of carnitine acyl CoA transferase in white perch heart. The substantial increase in carnitine acyl CoA transferase activity when unsaturated CoA derivatives were provided as substrate suggests an increased capacity to oxidize unsaturated fatty acids at low temperature following an acclimation period. Attempts to sustantiate this contention by offering labelled oleic acid to ventricle sheets were thwarted by a high rate of incorporation into the total lipid pool.

scholarly journals Activities of enzymes of ketone-body utilization in brain and other tissues of suckling rats

1971 ◽  
Vol 121 (1) ◽  
pp. 49-53 ◽  
Author(s):  
M. Ann Page ◽  
H. A. Krebs ◽  
D. H. Williamson
Keyword(s):  
Rat Brain ◽  
Ketone Body ◽  
Ketone Bodies ◽  
Rat Kidney ◽  
Adult Brain ◽  
Suckling Period ◽  
Suckling Rats ◽  
Adult Rat ◽  
Coa Transferase ◽  
High Concentrations

1. The activities of 3-hydroxybutyrate dehydrogenase and 3-oxo acid CoA-transferase in rat brain at birth were found to be about two-thirds of those of adult rat brain, expressed per g wet wt. The activities rose throughout the suckling period and at the time of weaning reached values about three times higher than those for adult brain. Later they gradually declined. 2. At birth the activity of acetoacetyl-CoA thiolase in rat brain was about 60% higher than in the adult. During the suckling period there was no significant change in activity. 3. In rat kidney the activities of the three enzymes at birth were less than one-third of those at maturity. They gradually rose and after 5 weeks approached the adult value. Similar results were obtained with rat heart. 4. The activity of glutamate dehydrogenase (a mitochondrial enzyme like 3-hydroxybutyrate dehydrogenase and 3-oxo acid CoA-transferase) also rose in brain and kidney during the suckling period, but at no stage did it exceed the adult value. 5. Throughout the suckling period the total ketone-body concentration in the blood was about six times higher than in adult fed rats, and the concentration of free fatty acids in the blood was three to four times higher. 6. It is concluded that the rate of ketone-body utilization in brains of suckling rats is determined by both the greater amounts of the key enzymes in the tissue and the high concentrations of ketone bodies in the blood. In addition, the low activities of the relevant enzymes in kidney and heart of suckling rats may make available more ketone bodies for the brain.

scholarly journals Activities of enzymes involved in acetoacetate utilization in adult mammalian tissues

1971 ◽  
Vol 121 (1) ◽  
pp. 41-47 ◽  
Author(s):  
D. H. Williamson ◽  
Margaret W. Bates ◽  
M. Ann Page ◽  
H. A. Krebs
Keyword(s):  
Ketone Body ◽  
Alloxan Diabetes ◽  
Adrenal Glands ◽  
Ketone Bodies ◽  
Rat Tissues ◽  
Adult Rat ◽  
Coa Transferase ◽  
Mammalian Tissues ◽  
Fat Feeding ◽  
Low Activity

1. The activities in rat tissues of 3-oxo acid CoA-transferase (the first enzyme involved in acetoacetate utilization) were found to be highest in kidney and heart. In submaxillary and adrenal glands the activities were about one-quarter of those in kidney and heart. In brain it was about one-tenth and was less in lung, spleen, skeletal muscle and epididymal fat. No activity was detectable in liver. 2. The activities of acetoacetyl-CoA thiolase were found roughly to parallel those of the transferase except for liver and adrenal glands. The high activity in the latter two tissues may be explained by additional roles of thiolase, namely, the production of acetyl-CoA from fatty acids. 3. The activities of the two enzymes in tissues of mouse, gerbil, golden hamster, guinea pig and sheep were similar to those of rat tissues. The notable exception was the low activity of the transferase and thiolase in sheep heart and brain. 4. The activities of the transferase in rat tissues did not change appreciably in starvation, alloxan-diabetes or on fat-feeding, where the rates of ketone-body utilization are increased. Thiolase activity increased in kidney and heart on fat-feeding. 5. The activity of 3-hydroxybutyrate dehydrogenase did not change in rat brain during starvation. 6. The factors controlling the rate of ketone-body utilization are discussed. It is concluded that the activities of the relevant enzymes in the adult rat do not control the variations in the rate of ketone-body utilization that occur in starvation or alloxan-diabetes. The controlling factor in these situations is the concentration of the ketone bodies in plasma and tissues.

Physical training reverses defect in 3-ketoacid CoA-transferase activity in skeletal muscle of diabetic rats

2005 ◽  
Vol 288 (4) ◽  
pp. E748-E752 ◽  
Author(s):  
Adil El Midaoui ◽  
Jean Louis Chiasson ◽  
Gilles Tancrède ◽  
André Nadeau
Keyword(s):  
Skeletal Muscle ◽  
Plasma Concentration ◽  
Physical Training ◽  
Ketone Bodies ◽  
Diabetic Rats ◽  
Transferase Activity ◽  
Hydroxybutyric Acid ◽  
Beneficial Effects ◽  
Coa Transferase ◽  
Key Enzyme

To investigate one potential mechanism whereby physical training improves the plasma concentration of ketone bodies in experimental diabetes mellitus, we measured the activity of 3-ketoacid CoA-transferase, the key enzyme in the peripheral utilization of ketone bodies. Diabetes was induced with streptozotocin (50 mg/kg) and training carried out on a treadmill with a progressive 10-wk program. Diabetes resulted in an increase ( P < 0.001) in plasma concentration of β-hydroxybutyric acid in sedentary rats, which was partly reversed by training ( P < 0.001). Diabetes was also associated with a decreased activity of 3-ketoacid CoA-transferase in gastrocnemius muscle. When expressed per total gastrocnemius, training increased the activity of 3-ketoacid CoA-transferase by 66% in nondiabetic rats ( P < 0.001) and by 150% in diabetic rats ( P < 0.001), the decrease present in diabetic rats being fully reversed by training. Simple linear regression between the log of 3-ketoacid CoA-transferase activity and the log of plasma β-hydroxybutyric acid levels showed a statistically significant ( r = 0.563, P < 0.001) negative correlation. The beneficial effects of training on plasma ketone bodies in diabetic rats are probably explained, at least in part, by an increase in ketone body utilization, mediated by an increase in skeletal muscle 3-ketoacid CoA-transferase activity.

scholarly journals Metabolism of glucose, glutamine, long-chain fatty acids and ketone bodies by murine macrophages

1986 ◽  
Vol 239 (1) ◽  
pp. 121-125 ◽  
Author(s):  
P Newsholme ◽  
R Curi ◽  
S Gordon ◽  
E A Newsholme
Keyword(s):  
Fatty Acids ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
The Body ◽  
Acid Cycle ◽  
Coa Transferase ◽  
Very High

Maximum activities of some key enzymes of metabolism were studied in elicited (inflammatory) macrophages of the mouse and lymph-node lymphocytes of the rat. The activity of hexokinase in the macrophage is very high, as high as that in any other major tissue of the body, and higher than that of phosphorylase or 6-phosphofructokinase, suggesting that glucose is a more important fuel than glycogen and that the pentose phosphate pathway is also important in these cells. The latter suggestion is supported by the high activities of both glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. However, the rate of glucose utilization by ‘resting’ macrophages incubated in vitro is less than the 10% of the activity of 6-phosphofructokinase: this suggests that the rate of glycolysis is increased dramatically during phagocytosis or increased secretory activity. The macrophages possess higher activities of citrate synthase and oxoglutarate dehydrogenase than do lymphocytes, suggesting that the tricarboxylic acid cycle may be important in energy generation in these cells. The activity of 3-oxoacid CoA-transferase is higher in the macrophage, but that of 3-hydroxybutyrate dehydrogenase is very much lower than those in the lymphocytes. The activity of carnitine palmitoyltransferase is higher in macrophages, suggesting that fatty acids as well as acetoacetate could provide acetyl-CoA as substrate for the tricarboxylic acid cycle. No detectable rate of acetoacetate or 3-hydroxybutyrate utilization was observed during incubation of resting macrophages, but that of oleate was 1.0 nmol/h per mg of protein or about 2.2% of the activity of palmitoyltransferase. The activity of glutaminase is about 4-fold higher in macrophages than in lymphocytes, which suggests that the rate of glutamine utilization could be very high. The rate of utilization of glutamine by resting incubated macrophages was similar to that reported for rat lymphocytes, but was considerably lower than the activity of glutaminase.

scholarly journals A high-MUFA diet alone does not affect ketone body metabolism, but reduces glycated hemoglobin when combined with exercise training in diabetic rats

2017 ◽  
Vol 9 (1) ◽  
pp. 31-40
Author(s):  
Juraiporn Somboonwong ◽  
Khunkhong Huchaiyaphum ◽  
Onanong Kulaputana ◽  
Phisit Prapunwattana
Keyword(s):  
Exercise Training ◽  
Ketone Body ◽  
Glycated Hemoglobin ◽  
Ketone Bodies ◽  
Transferase Activity ◽  
Nonesterified Fatty Acids ◽  
Regular Diet ◽  
Coa Transferase ◽  
Ketone Body Metabolism ◽  
Mufa Diet

Abstract Background Monounsaturated fat (MUFA) also has glucose-lowering action, but its effect on ketone bodies is unknown. Objectives To examine the effects of high-MUFA diet alone or in combination with exercise training, which can improve glucose and ketone body metabolism, in a rat model of diabetes. Methods Wistar rats were administered streptozotocin to induce diabetes and then randomly divided into five groups: sedentary rats fed a regular diet (1), a high-saturated-fat diet (2), a high-MUFA diet (3); and exercisetrained rats fed a regular diet (4), and a high-MUFA diet (5). Training was by a treadmill twice daily, 5 days/week. At 12 weeks, glucose, glycated hemoglobin (HbA1c), insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate levels were measured in cardiac blood. Activity of the overall ketone synthesis pathway was determined in liver and 3-ketoacyl-CoA transferase activity determined in gastrocnemius muscle. Results A high-MUFA diet tended to lower plasma glucose without affecting other biochemical variables. Training did not change glucose metabolism, but significantly reduced serum NEFA. Only the high-MUFA diet plus training significantly decreased HbA1c levels. Hepatic ketone synthesis was decreased and 3-ketoacyl-CoA transferase activity was increased by training alone or in combination with a high-MUFA diet. Changes in NEFA, β-hydroxybutyrate, and the enzymatic activities in response to training plus a high-MUFA diet were comparable to those caused by training alone. Conclusion A high-MUFA diet alone does not alter ketone body metabolism. Combination of a MUFA-rich diet and exercise training is more effective than either MUFA or exercise alone for lowering HbA1c.

scholarly journals The distribution of six enzymes of oxidative metabolism along the rat nephron.

1984 ◽  
Vol 32 (7) ◽  
pp. 731-736 ◽  
Author(s):  
H B Burch ◽  
T E Bross ◽  
C A Brooks ◽  
B R Cole ◽  
O H Lowry
Keyword(s):  
Malic Enzyme ◽  
Quantitative Methods ◽  
Citrate Synthase ◽  
Rat Kidney ◽  
Acid Oxidation ◽  
Keto Acid ◽  
Coa Transferase ◽  
Freeze Dried ◽  
Wide Range ◽  
Thin Limb

Using quantitative methods, citrate synthase (CS), fumarase, beta-hydroxyacyl-coenzyme A (CoA) dehydrogenase (beta OAC), 3-keto-acid CoA transferase (KCT), malic dehydrogenase (MDH), and malic enzyme were measured in seven defined parts of the nephron and in thin limb and papilla areas dissected from freeze-dried microtome sections of rat kidney. The results not only show a wide range of activity along the nephron for each of the enzymes, but that the proportions between the enzymes vary markedly among the different parts of the nephron. This suggests the existence of major regional differences in the capacity to oxidize specific metabolites. The ratio between two citrate cycle enzymes, fumarase and CS, was 4- or 5-fold higher in proximal segments than in the glomerulus or thin limb areas. The ratio between beta OAC (an enzyme of fatty acid oxidation) and CS was 3- to 5-fold higher in the middle proximal segments than in glomeruli or thin limb and papilla areas. The key enzyme for ketone body metabolism, KCT, was essentially confined to the thick tubule segments. Malic enzyme, in contrast to the other five enzymes, was highest in the proximal straight segments. New methods, sufficiently sensitive for this histochemical study, are described for malic enzyme and 3-keto-acid CoA transferase.

Thyroid hormones regulate development of energy metabolism enzymes in rat proximal convoluted tubule

1995 ◽  
Vol 268 (4) ◽  
pp. F634-F642 ◽  
Author(s):  
A. Wijkhuisen ◽  
F. Djouadi ◽  
J. Vilar ◽  
C. Merlet-Benichou ◽  
J. Bastin
Keyword(s):  
Thyroid Hormones ◽  
Proximal Tubule ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Proximal Convoluted Tubule ◽  
Oxidative Enzymes ◽  
Mitochondrial Enzymes ◽  
Carnitine Acetyltransferase ◽  
Coa Transferase ◽  
Metabolism Enzymes

Ketone bodies represent preferred energy substrates in the adult rat proximal tubule. They are abundant in the plasma of suckling rats and might represent an important oxidative substrate for the immature proximal tubule. The postnatal development of two enzymes involved in ketone body oxidation pathway, 3-ketoacid-CoA transferase and acetoacetyl-CoA thiolase, and of citrate synthase and carnitine acetyltransferase was studied in microdissected rat proximal convoluted tubule (PCT) at 1, 8, 16, and 21 days after birth. The enzyme levels in PCT of juxtamedullary and subcapsular nephrons were compared at 8, 16, and 21 days. A role of thyroid hormones in regulating the development of these enzymes was investigated by studying 8- and 21-day-old pups made hypothyroid by propylthiouracyl (PTU) treatment, as well as 21-day hyperthyroid rats. PTU treatment had no effect on enzyme activities on day 8. In contrast, the activity of all mitochondrial enzymes, except acetoacetyl-CoA thiolase, was significantly decreased in 21-day-old hypothyroid pups. In hypothyroid animals, the normal development of 3-ketoacid-CoA transferase, citrate synthase, and carnitine acetyltransferase could be restored after treatment by triiodothyronine (T3). In addition, one single injection of T3 to 8-day-old control pups induced a precocious rise in the activity of 3-ketoacid-CoA transferase, citrate synthase, and carnitine acetyltransferase in juxtamedullary PCT and in the activity of citrate synthase and carnitine acetyltransferase in subcapsular PCT. Altogether, these results point out the importance of the postnatal physiological rise in T3 in triggering the development of some mitochondrial oxidative enzymes in the PCT.

Effect of fluoxetine treatment on mitochondrial bioenergetics in central and peripheral rat tissues

2015 ◽  
Vol 40 (6) ◽  
pp. 565-574 ◽  
Author(s):  
Aline Isabel da Silva ◽  
Glauber Ruda Feitoza Braz ◽  
Reginaldo Silva-Filho ◽  
Anderson Apolonio Pedroza ◽  
Diorginis Soares Ferreira ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Metabolic Diseases ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Wistar Rat ◽  
Male Rats ◽  
Mitochondrial Activity ◽  
Rat Tissues ◽  
Transferase Activity ◽  
Mitochondrial Bioenergetics

Recent investigations have focused on the mitochondrion as a direct drug target in the treatment of metabolic diseases (obesity, metabolic syndrome). Relatively few studies, however, have explicitly investigated whether drug therapies aimed at changing behavior by altering central nervous system (CNS) function affect mitochondrial bioenergetics, and none has explored their effect during early neonatal development. The present study was designed to evaluate the effects of chronic treatment of newborn male rats with the selective serotonin reuptake inhibitor fluoxetine on the mitochondrial bioenergetics of the hypothalamus and skeletal muscle during the critical nursing period of development. Male Wistar rat pups received either fluoxetine (Fx group) or vehicle solution (Ct group) from the day of birth until 21 days of age. At 60 days of age, mitochondrial bioenergetics were evaluated. The Fx group showed increased oxygen consumption in several different respiratory states and reduced production of reactive oxygen species, but there was no change in mitochondrial permeability transition pore opening or oxidative stress in either the hypothalamus or skeletal muscle. We observed an increase in glutathione S-transferase activity only in the hypothalamus of the Fx group. Taken together, our results suggest that chronic exposure to fluoxetine during the nursing phase of early rat development results in a positive modulation of mitochondrial respiration in the hypothalamus and skeletal muscle that persists into adulthood. Such long-lasting alterations in mitochondrial activity in the CNS, especially in areas regulating appetite, may contribute to permanent changes in energy balance in treated animals.

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