Search results for "Citrate synthase"
showing 10 items of 28 documents
Effects of a high-fat diet on energy metabolism and ROS production in rat liver.
2011
International audience; BACKGROUND & AIMS: A high-fat diet affects liver metabolism, leading to steatosis, a complex disorder related to insulin resistance and mitochondrial alterations. Steatosis is still poorly understood since diverse effects have been reported, depending on the different experimental models used. METHODS: We hereby report the effects of an 8 week high-fat diet on liver energy metabolism in a rat model, investigated in both isolated mitochondria and hepatocytes. RESULTS: Liver mass was unchanged but lipid content and composition were markedly affected. State-3 mitochondrial oxidative phosphorylation was inhibited, contrasting with unaffected cytochrome content. Oxidative…
Endurance training decreases the alkaline proteolytic activity in mouse skeletal muscles.
1984
Alkaline and myofibrillar protease activities of rectus femoris, soleus, and tibialis anterior muscles and the pooled sample of gastrocnemius and plantaris muscles were analyzed in male NMRI-mice during a running-training program of 3, 10, or 20 daily 1-h sessions. The activity of citrate synthase increased during the endurance training, reflecting the increased oxidative capacity of skeletal muscles. The activities of alkaline and myofibrillar proteases continually decreased in the course of the training program in all muscles studied. Instead, the activity of beta-glucuronidase (a marker of lysosomal hydrolases) increased in all muscles. The highest activities were observed at the beginni…
New molecular aspects of regulation of mitochondrial activity by fenofibrate and fasting
2000
Abstract Fenofibrate and fasting are known to regulate several genes involved in lipid metabolism in a similar way. In this study measuring several mitochondrial enzyme activities, we demonstrate that, in contrast to citrate synthase and complex II, cytochrome c oxidase (COX) is a specific target of these two treatments. In mouse liver organelles, Western blot experiments indicated that mitochondrial levels of p43, a mitochondrial T3 receptor, and mitochondrial peroxisome proliferator activated receptor (mt-PPAR), previously described as a dimeric partner of p43 in the organelle, are increased by both fenofibrate and fasting. In addition, in PPARα-deficient mice, this influence was abolishe…
Citrate lyases of lactic acid bacteria
1998
Citrate Iyase is a key enzyme of the citrate metabolism which is involved in flavor and texture of many fermented milk products. Citrate Iyase which catalyses the cleavage of citrate into oxaloacetate and acetate is a multienzyme complex composed of three proteins: an acyl carrier protein (ACP); a citrate, acetate-ACP transferase; and a citryl-S-ACP Iyase. The citrate Iyase is active only when the thioester residue of the prosthetic group bound to ACP is acetylated. In the presence of citrate, the transferase mediates the formation of citryl-S-acyl carrier protein by acyl exchange and liberation of acetate. Then the Iyase subunit cleaves the citryl-S-ACP with libe- ration of oxaloacetate an…
Effects of endurance training on alkaline protease activities in rat skeletal muscles.
1983
This study aimed at comparing the effects of running and swimming training protocols and the termination of training on the activities of two proteases with alkaline pH-optima (alkaline protease and myofibrillar protease) in the tibialis anterior, soleus, and gastrocnemius muscles of male rats. The training on treadmill decreased the activities of alkaline and myofibrillar proteases by approx. 10-20% in the muscles studied. The activities of both proteases were unchanged in swimming-trained rats. Two weeks after the termination of running training the activity of alkaline protease was increased in gastrocnemius muscle but not in the other muscles. Swimming training increased the activity of…
Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities
1978
The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different tran…
Effects of indole-3-acetic acid on Sinorhizobium meliloti survival and on symbiotic nitrogen fixation and stem dry weight production
2009
We evaluated the effects of the main auxin phytohormone, indole-3-acetic acid (IAA), on the central metabolism of Sinorhizobium meliloti strain 1021. We either treated the Sinorhizobium meliloti 1021 strain with 0.5 mM IAA (1021+) or use a derivative, RD64, of the same strain harbouring a pathway for IAA biosynthesis converting tryptophan into IAA via indoleacetamide. We assayed the activity of key enzymes in the major energy-yielding pathways (Entner-Doudoroff, Embden-Meyerhof-Parnas, pentose phosphate, glyoxylate bypass and tricarboxylic acid cycle). We found that activity of two main regulative tricarboxylic acid (TCA) cycle enzymes was increased. Citrate synthase (CS) activity, as compa…
Aerobic Exercise During Advance Stage of Uncontrolled Arterial Hypertension
2021
Made available in DSpace on 2022-04-29T08:45:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-03 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidade Estadual Paulista Aim: To evaluate the influence of physical training on myocardial function, oxidative stress, energy metabolism, and MAPKs and NF-κB signaling pathways in spontaneously hypertensive rats (SHR), at advanced stage of arterial hypertension, which precedes heart failure development. Methods: We studied four experimental groups: normotensive Wistar rats (W, n = 27), trained W (W-EX, n = 31), SHR (n = 27), and exercised SHR (SHR-E…
The Measurement of Enzyme Activities in the Resting Human Polymorphonuclear Leukocyte — Critical Estimate of a Method
1993
As a system for study, the isolated human polymorphonuclear leukocyte combines the advantages of a quasi-non-invasive preparation with a nearly complete complement of enzymes of carbohydrate and energy metabolism. However, small sample volumes and, in some cases, very low enzyme activities make high demands on sample processing, storage, and performance of continuous measurements, if the enzyme activities are to be measured with acceptable reproducibility. In the presented study several aspects of homogenization, storage, and continuous measurement were scrutinized, to identify critical steps and consider ways of optimizing the method. Polymorphonuclear leukocytes were separated from the bl…
Mutation of the oxaloacetate decarboxylase gene of Lactococcus lactis subsp. lactis impairs the growth during citrate metabolism
2007
; Aims: Citrate metabolism generates metabolic energy through the generation of a membrane potential and a pH gradient. The purpose of this work was to study the influence of oxaloacetate decarboxylase in citrate metabolism and intracellular pH maintenance in relation to acidic conditions. Methods and Results: A Lactococcus lactis oxaloacetate decarboxylase mutant [ILCitM (pFL3)] was constructed by double homologous recombination. During culture with citrate, and whatever the initial pH, the growth rate of the mutant was lower. In addition, the production of diacetyl and acetoin was altered in the mutant strain. However, our results indicated no relationship with a change in the maintenanc…