Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SUCCINIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed2005

Characterization of depolarization and repolarization phases of mitochondrial membrane potential fluctuations induced by tetramethylrhodamine methyl ester photoactivation.

Depolarization and repolarization phases (D and R phases, respectively) of mitochondrial potential fluctuations induced by photoactivation of the fluorescent probe tetramethylrhodamine methyl ester (TMRM) were analyzed separately and investigated using specific inhibitors and substrates. The frequency of R phases was significantly inhibited by oligomycin and aurovertin (mitochondrial ATP synthase inhibitors), rotenone (mitochondrial complex I inhibitor) and iodoacetic acid (inhibitor of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase). Succinic acid (mitochondrial complex II substrate, given in the permeable form of dimethyl ester) abolished the rotenone-induced inhibition of R phases. Taken together, these findings indicate that the activity of both respiratory chain and ATP synthase were required for the recovery of the mitochondrial potential. The frequency of D phases prevailed over that of R phases in all experimental conditions, resulting in a progressive depolarization of mitochondria accompanied by NAD(P)H oxidation and Ca2+ influx. D phases were not blocked by cyclosporin A (inhibitor of the permeability transition pore) or o-phenyl-EGTA (a Ca2+ chelator), suggesting that the permeability transition pore was not involved in mitochondrial potential fluctuations.

Membrane Proteins↗
PubMed1991

Octenylsuccinic aciduria in children fed protein-hydrolysate formulas containing modified cornstarch.

The excretion of 2-(2'-octenyl)succinic acid (OSA) and several metabolites of OSA was studied by gas chromatography/mass spectrometry in 17 infants and children fed one of three proprietary elemental or protein-hydrolysate formulas that use OSA-modified cornstarch as an emulsifying agent. Variable but often large amounts (up to 2500 mg/g creatinine) of the fatty acid-like OSA and its metabolites were found in the urine of these children, and levels of OSA in their blood ranged from 9.5 to 57.9 mumol/L. Apparently secondary abnormalities, such as increased urinary levels of glutaric acid and 2-ketoglutaric acid, were also found in more than half of the urine specimens. The molecular weight and mass fragmentation patterns of the nine compounds associated with the excretion of OSA are consistent with the proposal that OSA is metabolized in human infants and children by a combination of omega-, omega-1-, and beta-oxidation steps, similar to the metabolism of another branched-chain fatty acid, valproic acid. The urinary organic acid pattern of children fed elemental formulas containing OSA-modified starch often was dominated by OSA and its metabolites, and in several children the OSA-related changes were mistaken for a primary metabolic disease. Physicians and laboratories evaluating children for suspected metabolic diseases should be aware of the possibility of abnormal organic acid studies associated with OSA-containing formulas.

Child↗
PubMed1999

[Determination of dicarboxylic acids in a new compound liquid fertilizer by gas chromatography].

A method for determination of succinic acid, glutaric acid and adipic acid in a new compound liquid fertilizer by gas chromatography is described. The sample after dried at 80 degrees C was extracted by ethyl alcohol, and then esterified in the presence of BF3. The esterified derivatives were injected into a gas chromatograph with a 5% SE-30 packed column, programmed from 140 degrees C (held for 1 min) to 160 degrees C (held for 6 min) at a rate of 6 degrees C/min. Internal standard was diethyl malonate. Calibration curves of the three diethyl esters were linear in the ranges of 2.3-9.3 micrograms, 10.8-43.2 micrograms and 2.8-11.0 micrograms respectively.

English Abstract↗
PubMed2006

Molecular cloning and characterization of a novel lactate dehydrogenase gene from Clonorchis sinensis.

From a Clonorchis sinensis adult worm cDNA library, we isolated a cDNA clone encoding a novel lactate dehydrogenase (LDH) gene which encoded a putative protein with a predicted molecular weight of 35.6 kDa. The optimum pH and temperature for the enzyme were 7.5 and 50 degrees C in the pyruvate reduction while 11 and 80 degrees C in the lactate oxidation reaction, respectively. CsLDH showed no substrate inhibition by high lactate and NAD(+) concentration, and the optimal pyruvate and optimal NADH concentrations were 10 and 0.5 mmol/l, respectively. The relative activities of these 2-oxocarboxylic acids were pyruvic acid>2-ketobutyrate>oxalacetic acid>alpha-ketoglutaric acid>phenylpyruvate. The cofactor 3-acetylpyridine adenine dinucleotide was much more effective than NAD(+). The cofactor analogs in which the nicotinamide ring is replaced by 3-pyridinealdehyde were lower activity cofactors, while the nicotinamide ring is replaced by nicotinic acid or thionicotinamide which is not a cofactor to CsLDH. The succinic acid and malic acid are not substrates of CsLDH. Cu(2+), Fe(2+), and Zn(2+) greatly inhibited the CsLDH activity both in the direction of pyruvate reduction and in the direction of lactate oxidation. The inhibition of CsLDH by gossypol may make gossypol a potential therapy drug or a lead compound for C. sinensis. Accordingly, the CsLDH may be a novel potential drug target.

Amino Acid Sequence↗
PubMed2005

Cytotoxicity of organic acids produced by anaerobic intestinal bacteria on cultured epithelial cells.

BACKGROUND: Anaerobic intestinal bacteria produce various organic acids. We identified the concentrations of various organic acids produced by intestinal bacteria needed to kill cultured cells. METHODS: Nine organic acids and their sodium salts were added to five epithelial cell lines and the cells were examined for cytotoxicity. To assess cytotoxicity, the colorimetric 3-(4,5-dimethyl-2-thiazoyl-2,5-diphenyl tetrazolium bromide (MTT) assay was performed. We calculated the lowest concentration that killed 50% of the cells by the MTT assay. Adherent and floating cells were collected 96 h after incubation for analysis of apoptosis by gel electrophoresis and flow cytometry. RESULTS: The minimum concentrations of the acids and sodium salts of n-butyric, propionic, isovaleric, and succinic acids capable of causing cytotoxicity were lower than the concentrations produced by intestinal bacteria. Apoptosis was found in all cell lines treated with the acids and the sodium salts of n-butyrate, isobutyrate, propionate, isovalerate, and n-valerate. However, no apoptosis was found in cells treated with the acid or sodium salts of formate and lactate. CONCLUSIONS: This study showed that acetate, butyrate, propionate, and valerate produced by intestinal bacteria could induce apoptosis at physiological concentrations. This cytotoxicity may contribute to the pathogenesis of colonic ulcers.

Apoptosis↗
PubMed1994

Reaction of 4-hydroxynonenal with some thiol-containing radioprotective agents or their active metabolites.

The rate of reaction of several radioprotective agents or their active metabolites with 4-hydroxynonenal (4HNE) was studied and compared to the rate of reaction with cysteine (Cys) and glutathione (GSH). The agents studied were: mercapto ethylamine (MEA); 2(3-aminopropyl) aminoethanethiol (WR1065); S-2-aminoethylisothiouronium bromide-hydrobromide (AET); 1,4-dithiothreitol (DTT); 1,4-dithioerythritol (DTE); N-2(2-mercaptopropionyl)-glycine (MPG); penicillamine hydrochloride (PA); N-acetylcysteine (NAC); 2-3 dimercapto-1 propane sulfonic acid (DMPS); 2,3-dimercaptopropanol (BAL), and meso 2,3 dimercapto succinic acid (DMS). All of them reacted with 4HNE. MEA and WR1065 were the most reactive thiols, and PA and DMS were the least reactive thiols. All the others reacted at rates comparable to or higher than that of cysteine or GSH. The potential role of this type of interactions in the protective action of these drugs against deleterious effects of radiation or carbon tetrachloride is analyzed.

Aldehydes↗
PubMed2004

Metabolic discrimination of Catharanthus roseus leaves infected by phytoplasma using 1H-NMR spectroscopy and multivariate data analysis.

A comprehensive metabolomic profiling of Catharanthus roseus L. G. Don infected by 10 types of phytoplasmas was carried out using one-dimensional and two-dimensional NMR spectroscopy followed by principal component analysis (PCA), an unsupervised clustering method requiring no knowledge of the data set and used to reduce the dimensionality of multivariate data while preserving most of the variance within it. With a combination of these techniques, we were able to identify those metabolites that were present in different levels in phytoplasma-infected C. roseus leaves than in healthy ones. The infection by phytoplasma in C. roseus leaves causes an increase of metabolites related to the biosynthetic pathways of phenylpropanoids or terpenoid indole alkaloids: chlorogenic acid, loganic acid, secologanin, and vindoline. Furthermore, higher abundance of Glc, Glu, polyphenols, succinic acid, and Suc were detected in the phytoplasma-infected leaves. The PCA of the (1)H-NMR signals of healthy and phytoplasma-infected C. roseus leaves shows that these metabolites are major discriminating factors to characterize the phytoplasma-infected C. roseus leaves from healthy ones. Based on the NMR and PCA analysis, it might be suggested that the biosynthetic pathway of terpenoid indole alkaloids, together with that of phenylpropanoids, is stimulated by the infection of phytoplasma.

Catharanthus↗
PubMed1979

Isolation and characterization of large treponemes from the bovine rumen.

Ten strains of strictly anaerobic spiral organisms were isolated in pure culture from a 10(-7) dilution of bovine rumen contents. Three strains were studied in detail. These strains morphologically resembled previously isolated and described rumen treponemes except the new isolates were larger, 0.7 micrometer wide and 12 to 25 micrometer long. They rapidly fermented pectin and, less readily, L-arabinose, inulin, and sucrose. Acetic and formic acid were the main fermentation products from pectin; small amounts of succinic acid were also formed.

Anaerobiosis↗
PubMed1990

Inducible overexpression of the FUM1 gene in Saccharomyces cerevisiae: localization of fumarase and efficient fumaric acid bioconversion to L-malic acid.

Cloning of the Saccharomyces cerevisiae FUM1 gene downstream of the strong GAL10 promoter resulted in inducible overexpression of fumarase in the yeast. The overproducing strain exhibited efficient bioconversion of fumaric acid to L-malic acid with an apparent conversion value of 88% and a conversion rate of 80.4 mmol of fumaric acid/h per g of cell wet weight, both of which are much higher than parameters known for industrial bacterial strains. The only product of the conversion reaction was L-malic acid, which was essentially free of the unwanted by-product succinic acid. The GAL10 promoter situated upstream of a promoterless FUM1 gene led to production and correct distribution of the two fumarase isoenzyme activities between cytosolic and mitochondrial subcellular fractions. The amino-terminal sequence of fumarase contains the mitochondrial signal sequence since (i) 92 of 463 amino acid residues from the amino terminus of fumarase are sufficient to localize fumarase-lacZ fusions to mitochondria and (ii) fumarase and fumarase-lacZ fusions lacking the amino-terminal sequence are localized exclusively in the cytosol. The possibility that both mitochondrial and cytosolic fumarases are derived from the same initial translation product is discussed.

Cloning, Molecular↗
PubMed1973

Simplified gas chromatographic procedure for identification of bacterial metabolic products.

A rapid and simple procedure is described for analysis of fermentation products from anaerobic bacteria grown in glucose broth. A 1-ml sample of the culture is drained through cation-exchange resin in a Pasteur pipette. The effluent fluid is directly analyzed isothermally in a gas chromatograph for volatile fatty acids (C(2) to C(6)) as well as for lactic, pyruvic, and succinic acids. This procedure is considered to be suitable for routine use in clinical bacteriology.

Anaerobiosis↗
PubMed1995

gamma-Aminobutyric acid (GABA) metabolism in mammalian neural and nonneural tissues.

4-Aminobutyric acid (GABA), a major inhibitory neurotransmitter of mammalian central nervous system, is found in a wide range of organisms, from prokaryotes to vertebrates. GABA is widely distributed in nonneural tissue including peripheral nervous and endocrine systems. GABA acts on GABAA and GABAB receptors. GABAA receptors are ligand-gated chloride channels modulated by a variety of drugs. GABAB receptors are essentially presynaptic, usually coupled to potassium or calcium channels, and they function via a GTP binding protein. In neural and nonneural tissues, GABA is metabolized by three enzymes--glutamic acid decarboxylase (GAD), which produces GABA from glutamic acid, and the catabolic enzymes GABA-transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). Production of succinic acid by SSADH allows entry of the GABA carbon skeleton into the tricarboxylic acid cycle. Alternate sources of GABA include putrescine, spermine, spermidine and ornithine, which produce GABA via deamination and decarboxylation reactions, while L-glutamine is an additional source of glutamic acid via deamination. GAD from mammalian brain occurs in two molecular forms, GAD65 and GAD67 (referring to subunit relative molecular weight (Mr) in kilodaltons). These different forms of GAD are the product of different genes, differing in nucleotide sequence, immunoreactivity and subcellular localization. The presence and characteristics of GAD have been investigated in a wide variety of nonneural tissues including liver, kidney, pancreas, testis, ova, oviduct, adrenal, sympathetic ganglia, gastrointestinal tract and circulating erythrocytes. In some tissues, one form (GAD65 or GAD67) predominates. GABA-T has been located in most of the same tissues, primarily through histochemical and/or immunochemical methods; GABA-T is also present in a variety of circulating cells, including platelets and lymphocytes. SSADH, the final enzyme GABA catabolism, has been detected in some of the tissues in which GAD and GABA-T have been identified, although the presence of this enzyme has not been in mammalian pancreas, ova, oviduct, testis or sympathetic ganglia.

Animals↗
PubMed2006

Radiolabeled L-lysine for tumor imaging.

RATIONALE AND OBJECTIVES: The aims of this study were to label the versatile amino acid l-lysine with (99m)Tc using 2,3-dimercapto-succinic acid (DMSA) as a chelator, and to assess its tumor imaging feasibility under in vivo and in vitro conditions, and finally to determine the subcellular biodistribution of this radiopharmaceutical. MATERIALS AND METHODS: DMSA-l-lysine was chemically synthesized and labeled with sodium pertechnetate. Nuclear magnetic resonance (NMR) and mass spectral analysis of DMSA-l-lysine were conducted. Radiochemical purity was determined by thin-layer chromatography (TLC) and paper chromatography. Cellular uptake, competition and subcellular localization studies were performed in rat breast cancer cells (13762). In vivo studies of planar imaging and biodistribution studies were performed on female Fischer 344 rats. Medical Internal Radiation Dose (MIRD) dosimetry estimates were calculated. RESULTS: Radiochemical purity (determined by radio-TLC and high-performance liquid chromatography) of these compounds was >95%. (99m)Tc-DMSA-l-lysine showed good uptake in in vitro cell culture assays and uptake was reduced in competition studies. (99m)Tc-DMSA-l-lysine accumulates in the nucleus as much as in the cytoplasm and it was also shown that accumulation of the (99m)Tc-DMSA-l-lysine in the nucleus increases as a function of a time. There was an increase in tumor-to-blood and tumor-to-muscle count density ratios. Tumor/background ratios were 5.75 at 1 hour and 6.87 at 2 hours. In vivo tissue distribution studies revealed that radiation dosimetry of blood-forming organs were within radiation dose limits. CONCLUSION: DMSA-l-lysine kits can be labeled with (99m)Tc easily and efficiently, with high radiochemical purity and cost-effectiveness. In vitro cellular uptake and scintigraphic imaging studies demonstrated the pharmacokinetic distribution and feasibility of using (99m)Tc-DMSA-l-lysine for tumor imaging.

Adenocarcinoma↗
PubMed2000

Comparative study on chemical changes in olive juice and brine during green olive fermentation.

Changes in physicochemical characteristics, substrate depletion, and product formation during fermentation were followed in both brine and olive juice in order to achieve a complete knowledge of fermentation chemistry in Spanish-type green olives. Both spontaneous and controlled fermentations were investigated. Fermentation rate, irrespective of the type of fermentation, was lower in olive juice than in brine, but the main acid products eventually reached equilibrium. Final free acidity remained significantly (p < 0.05) higher, and combined acidity remained lower, in brine than in olive juice in both fermentations, but differences in final pH were not significant in controlled fermentation. Final concentrations of lactic and formic acids were significantly (p < 0. 05) higher, and those of ethanol and succinic acid were lower, in controlled fermentation than in spontaneous fermentation. Butanediol, attributable to Enterobacteriaceae growth, was formed only in the latter case. Calculated carbon recoveries were not significantly (p < 0.05) different in any case, giving a mean of some 78%.

Fermentation↗
PubMed1981

Prevention of surface mold growth on Italian dry sausage by natamycin and potassium sorbate.

Inhibition of uncontrolled mold growth on three types of raw cured Italian dry salami was studied under commercial production conditions. Salami were dipped or sprayed with natamycin (pimaricin) or were given a combined organic acid-plus-potassium sorbate treatment. Acetic and citric acids potentiated the inhibitory effects of potassium sorbate significantly, but lactic and succinic acids showed little or no effect. Treatment of salami by dipping in 2.5% (wt/vol) potassium sorbate or 2,000 ppm (mg/liter) of pimaricin did not successfully prevent the growth of surface molds. At 10% potassium sorbate on all types of salami and at 2.5% sorbate on Casalingo salami, visual inhibition of mold growth was observed, but numbers of viable fungi on all salami types treated with 2.5% sorbate were not significantly (95% confidence) different from numbers found in the untreated controls. Pimaricin spray (2 X 1,000 ppm) was as good as or slightly better than 2.5% potassium sorbate, but greater concentrations of each were required to satisfactorily inhibit surface mold growth during the 25- to 50-day ripening period.

Antifungal Agents↗
PubMed2005

The GABA shunt: an attractive and potential therapeutic target in the treatment of epileptic disorders.

Epilepsy is the most common primary neurological disorder known. Epileptiform neurons undergo paroxysmal depolarization shifts (PDS), which result in the excessive sustained neuronal firing seen in epilepsy. These shifts are due to either an impairment of GABA mediated inhibition, or an enhancement of aspartate or glutamate mediated excitatory transmission. Recent research has focused on the cellular biology of seizures. 4-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter of mammalian central nervous system. In neural and nonneural tissues, GABA is metabolized by three enzymes-glutamic acid decarboxylase (GAD), which produces GABA from glutamic acid, and the catabolic enzymes GABA-transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). Production of succinic acid by SSADH allows entry of the GABA carbon skeleton into the tricarboxylic acid cycle. GABA-T is present in a variety of circulating cells, including platelets and lymphocytes. SSADH, the final enzyme of GABA catabolism, has been detected in some of the tissues in which GAD and GABA-T have been identified. This paper is aimed at elucidating the organization of the GABA shunt and covers a review on the antiepileptic drugs, both established and currently under development targeted to the GABA shunt in order to bring about effective seizure control.

Animals↗