Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROPIONATES”

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 721 records · Page 40Linked to original sources
PubMed2004

The efficiency of enhanced biological phosphorus removal from real wastewater affected by different ratios of acetic to propionic acid.

The effect of different ratios of propionic to acetic acid on the efficiency of enhanced biological phosphorus removal (EBPR) from real wastewater supplemented with volatile fatty acids (VFAs) was investigated. Two sequencing batch reactors (SBRs) were used to acclimate two types (SBR1 and SBR2) of biomass. They were cultured and studied using real wastewater with an average propionic to acetic acid carbon molar ratio of 0.16 and 2.06, respectively. The laboratory results showed that for a given long-term cultured biomass the more the soluble ortho-phosphate (SOP) was released in the anaerobic stage, the higher the SOP was taken up in the aerobic phase. However, the SBR2 biomass had a much greater SOP uptake to release ratio than SBR1, which resulted in a higher SOP removal efficiency than SBR1 (average 87.3% versus 76.9% in SBRs experiments, and 93.5% against 68.1% in batch tests). The SBR2 biomass therefore had a higher SOP uptake ability than the SBR1 for a given amount of SOP release. In addition, the SBR1 had a higher secondary SOP release following VFAs uptake. It was found that the SBR2 biomass synthesized and utilized less observable polyhydroxyalkanoates (PHAs) during the anaerobic and aerobic stage respectively than SBR1. The apparent PHAs utilization efficiency for SOP uptake with the SBR2 biomass was much greater than with the SBR1, and the SBR2 biomass synthesized less glycogen during aerobiosis than SBR1, which might mean a higher PHAs fraction was used for SOP removal, resulting in the increased efficiency with the long-term cultured SBR2 biomass. Higher propionic acid content led to superior EBPR in long-term cultivation, but was transiently detrimental in the short term.

Acetic Acid↗
PubMed1997

Measurement of gluconeogenesis and pyruvate recycling in the rat liver: a simple analysis of glucose and glutamate isotopomers during metabolism of [1,2,3-(13)C3]propionate.

Simple equations that relate glucose and glutamate 13C-NMR multiplet areas to gluconeogenesis and pyruvate recycling during metabolism of [1,2,3-(13)C3]propionate are presented. In isolated rat livers, gluconeogenic flux was 1.2 times TCA cycle flux and about 40% of the oxaloacetate pool underwent recycling to pyruvate prior to formation of glucose. The 13C spectra of glucose collected from rats after gastric versus intravenous administration of [1,2,3-(13)C3]propionate indicated that pyruvate recycling was slightly higher in vivo (49%) while glucose production was unchanged. This indicates that a direct measure of gluconeogenesis and pyruvate recycling may be obtained from a single 13C-NMR spectrum of blood collected after oral administration of enriched propionate.

Animals↗
PubMed1999

High resolution affinity chromatography of an anti-steroid antiserum by gradient elution with propionic acid.

Chromatographic resolution of polyclonal antibodies is a challenging analytical problem and a successful method may have many applications. We have resolved polyclonal antibodies against testosterone 3-(O-carboxymethyl)oxime on a homologous testosterone-Sepharose matrix by using a ternary gradient system of propionate-1 M propionic acid-2 M propionic acid. Nineteen peaks were detected, sixteen of which were characterized by steroid binding activity and IgG assay. The relative affinities of the pooled fractions, determined by ELISA and by thiocyanate elution, correlated well with their retention times. The slopes of the displacement curves in antigen-immobilized testosterone ELISA increased with retention times of the fractions; testosterone required for 50% displacement being, 90, 5.8 and 24 ng/well for fraction I, fraction XVI and total antiserum, respectively. Cross-reactivity of the fractions towards 5alpha-dihydrotestosterone varied from 31 to 74% compared to 47% in the total antiserum.

Animals↗
PubMed1995

Neonatal-onset propionic acidemia: neurologic and developmental profiles, and implications for management.

OBJECTIVES: To document the clinical and neurodevelopmental profiles of a cohort of patients with neonatal-onset propionic acidemia and to determine the efficacy of current therapy with respect to outcome. METHOD: The clinical, neurologic, and developmental status of six patients was prospectively evaluated during a 15-month period. Previous clinical and biochemical data were ascertained from hospital records to determine longitudinal nutritional status, number of episodes of hyperammonemia with ketoacidosis, and developmental performance with respect to age. RESULTS: No deaths resulted from propionic acidemia since the identification of the oldest patient in the series in 1980. Therapeutic intervention (e.g., gastrostomy tube feeding) resulted in improved nutritional status and possibly contributed to improved survival. All children had hypotonia, resulting in a significant effect on motor development; however, focal neurologic deficits and evidence of movement or seizure disorder were absent. Mild cortical atrophy was evident on cranial magnetic resonance imaging in four patients. All children, including two patients with no significant episodes of hyperammonemia and normal growth since the neonatal period, had a mild to moderate degree of intellectual impairment. CONCLUSIONS: The results of our study suggest that current therapy for neonatal-onset propionic acidemia is associated with improved survival and nutritional status, and an absence of focal neurologic deficits. However, hypotonia and cognitive delay were still present, even in children with "optimal" metabolic control. Additional therapeutic advances are required to improve the developmental and cognitive outcome.

Carboxy-Lyases↗
PubMed1999

Effect of chemically induced propionic acidemia on neurobehavioral development of rats.

High levels of propionic acid (PPA) comparable to those of human propionic acidemia were achieved in blood (1-5 mmol/l) and brain (1 micromol/g) of rats by administering saline-buffered propionate (pH 7.4) subcutaneously twice a day from the 6th to the 28th day of life. PPA doses ranged from 1.44 to 1.92 micromol/g body weight as a function of animal age. Control rats were treated with saline in the same volumes. Growth and development of physical landmarks were assessed by monitoring the following parameters daily: body weight, upper incisor eruption, eye opening, and hair coat. Development of some reflexes was also monitored, and a specific subset of motor skills was evaluated at days 14 and 21 of life by the free-fall righting test and the spontaneous alternation test. Chronic PPA administration had no effect on body weight, cerebral cortex weight, or cerebellum weight, but caused slight but significant delays in the day of appearance of hair coat and eye opening, indicating an effect of PPA on the development of physical parameters. Free-fall righting was impaired in PPA-treated animals. On the other hand, PPA administration had no effect on the performance of the animals in the spontaneous alternation tests. Long-term effects of early PPA administration were investigated by assessing animal performance in an aversive task (two-way shuttle avoidance task) and in a nonaversive (open-field task) behavioral task at 60 days of age. PPA-treated rats did not habituate to the open field, and presented a lack of retention of the shuttle-avoidance task. Our results suggest that early postnatal PPA administration to rats alters normal development and induces long-term behavioral deficits in aversive and nonaversive tasks.

Acidosis↗
PubMed1998

Effects of acute and chronic administration of methylmalonic and propionic acids on the in vitro incorporation of 32P into cytoskeletal proteins from cerebral cortex of young rats.

We studied the effects of acute and chronic administration of methylmalonic (MMA) and propionic (PA) acids on the in vitro incorporation of 32P into neurofilament subunits (NF-M and NF-L), alpha and beta tubulins, from cerebral cortex of rats. In the chronic treatment, drugs were administered subcutaneously from day 6-17 post-partum (MMA 0.76-0.89 micromol/g body weight and PA 0.93 micromol/g body weight). In the acute treatment MMA and PA were injected (MMA 3.78 micromol/g body weight and PA 3.90 micromol/g body weight). Control animals received saline in the same volumes. The Triton-insoluble cytoskeletal fraction of control in treated animals was isolated and incubated with 32P-ATP. Our results demonstrate that both drugs were able to inhibit 32P in vitro incorporation into neurofilaments and tubulins. The acute administration of MMA decreased the in vitro 32P incorporation into NF-L and alpha-tubulin subunit, whereas PA administration decreased the 32P in vitro incorporation into NF-M, NF-L, and tubulins. On the other hand, chronic MMA administration induced a decreased 32P in vitro incorporation into NF-M, while chronic treatment with propionate decreased the in vitro phosphorylation of NF-M and alpha-tubulin. This study provides consistent evidence that a decreased phosphorylation of cytoskeletal proteins is induced by MMA and PA metabolites which accumulate in methylmalonic and propionic acidemias respectively. Therefore, it is possible that an altered brain cytoskeletal metabolism could be related with the structural alterations of CNS observed in these disorders.

Animals↗
PubMed1999

Formation of propionate after short-term ethanol treatment and its interaction with the carnitine pool in rat.

Organic acidurias are genetic disorders of mitochondrial metabolism that lead to the accumulation in tissues and biological fluids of organic acids. It has been demonstrated that interaction of carnitine with the cellular CoA pool, through the production of acyl-carnitines, is potentially critical for maintaining normal cellular metabolism under conditions of impaired acyl-CoA use and that exposure of humans and other mammals to ethanol effects leads to impairment of mitochondrial function. The aim of the present study was to evaluate the role of ethanol on urinary excretion of short-chain organic acids and endogenous carnitines in rats. The data reported show that ethanol significantly increases urinary excretion of propionate, methylmalonate, as well as free acetate, butyrate, pyruvate, lactate, and beta-hydroxybutyrate. Furthermore, the increased formation of propionate and methylmalonate was dependent on the dose of ethanol; did not require the metabolism of ethanol, as was shown in experiments with pyrazole treatment of ethanol rats; and appears to be mediated by beta-adrenergic mechanisms because propranolol almost completely suppresses propionate accumulation. Alcohol administration also increased excretion of specific acyl-carnitines, corresponding to the accumulating acyl groups, whereas excretion of free carnitine was significantly reduced, with respect to control values. The data presented indicate that the short-term ethanol administration is associated with increased excretion of selected organic acids. This study suggests that endogenous carnitine pool might play a role against the deleterious effects of accumulating short-chain organic acids.

Acids, Acyclic↗
PubMed2003

Propionic acidemia: identification of twenty-four novel mutations in Europe and North America.

Propionic acidemia is an inherited metabolic disease caused by the deficiency of the mitochondrial protein propionyl-CoA carboxylase (PCC), one of the four biotin-dependent enzymes. PCC is a multimeric protein composed of two different alpha- and beta-PCC subunits, nuclearly encoded by the PCCA and PCCB genes, respectively. Mutations in either gene cause the clinically heterogeneous disease propionic acidemia. In this work we describe the mutational analysis of PCCA and PCCB deficient patients from different European countries (Spain, Italy, Belgium, Croatia, and Austria) and from America (mainly USA). We report 24 novel PA mutations, nine affecting the PCCA gene and 15 affecting the PCCB gene. They include six missense mutations, one nonsense mutation, one point exonic mutation affecting splicing, seven splicing mutations affecting splice sequences, and nine short insertions or deletions, only two in-frame. We have found a highly heterogenous spectrum of PCCA mutations, most of the PCCA deficient patients are homozygous carrying a unique genotype. The PCCA mutational spectrum includes a high proportion of short insertions or deletions affecting one nucleotide. In the PCCA mutant alleles analyzed we have also found one single nucleotide change, a novel nonsynonymous SNP. On the other hand, the PCCB deficient patients carry a more reduced spectrum of mutations, 50% of them are missense. This work represents an extensive update of the mutational study of propionic acidemia providing important information about the worldwide distribution of PA mutations and representing another essential part in the study of the phenotype-genotype correlations for the prediction of the metabolic outcome and for the implementation of treatments tailored to each PA patient.

Alternative Splicing↗
PubMed2005

[Infantile spasms as the first manifestation of propionic acidemia].

Propionic acidemia is a disorder of branch-chain amino acids, the side chain of cholesterol and odd-chain fatty acid metabolism that leads to the accumulation of toxic acid metabolites. The clinical features typically begin shortly after birth, although they can also appear in young adulthood. We report the case of a 3-year-old boy with atypical onset, who at 6 months presented bursts of infantile spasms and a hypsarrhythmic electroencephalogram. He was treated with vigabatrin. At 8 months magnetic resonance imaging showed a wider than normal subarachnoidal space, and hyperintense thalamus, globus pallidus and subthalamic nucleus. Biochemical and genetic analysis confirmed propionic acidemia. Specific therapy was started and the patient is not currently under anti-epileptic treatment and his electroencephalogram is normal. This onset of propionic acidemia is unusual, and we believe that treatment with vigabatrin protected the basal ganglia from irreversible excitotoxic damage.

Age of Onset↗
PubMed2004

Phe393 mutants of cytochrome P450 BM3 with modified heme redox potentials have altered heme vinyl and propionate conformations.

It has been well established that the heme redox potential is affected by many different factors. Among others, it is sensitive to the proximal heme ligand and the conformation of the propionate and vinyl groups. In the cytochrome P450 BM3 heme domain, substitution of the highly conserved phenylalanine 393 results in a dramatic change in the heme redox potential [Ost, T. W. B., Miles, C. S., Munro, A. W., Murdoch, J., Reid, G. A., and Chapman, S. K. (2001) Biochemistry 40, 13421-13429]. We have used resonance Raman spectroscopy to characterize heme structural changes and modification of heme interactions with the protein matrix that are induced by the F393 substitutions and to determine their correlation with the heme redox potential. Our results show that the Fe-S stretching frequency of the 5-coordinated, high-spin ferric heme is not affected by the mutations, suggesting that the electron density in the Fe-S bond in this state is not affected by the F393 mutation and is not a good indicator of the heme redox potential. Substrate binding perturbs the hydrogen bonding between one propionate group and the protein matrix and correlates to both the size of residue 393 and the heme redox potential. However, heme reduction does not affect the conformation of the propionate groups. Although the conformation of the vinyl groups is not affected much by substrate binding, their conformation changes from mainly out-of-plane to predominantly in-plane upon heme reduction. The extent of these conformational changes correlates strongly with the size of the 393 residue and the heme redox potential, suggesting that steric interaction between this residue and the vinyl groups may be of importance in regulating the heme redox potential in the P450 BM3 heme domain. Further implications of our findings for the change in redox potential upon mutation of F393 will be discussed.

Amino Acid Substitution↗
PubMed2005

An arginine to lysine mutation in the vicinity of the heme propionates affects the redox potentials of the hemes and associated electron and proton transfer in cytochrome c oxidase.

Cytochrome c oxidase pumps protons across a membrane using energy from electron transfer and reduction of oxygen to water. It is postulated that an element of the energy transduction mechanism is the movement of protons to the vicinity of the hemes upon reduction, to favor charge neutrality. Possible sites on which protons could reside, in addition to the conserved carboxylate E286, are the propionate groups of heme a and/or heme a(3). A highly conserved pair of arginines (R481 and R482) interact with these propionates through ionic and hydrogen bonds. This study shows that the conservative mutant, R481K, although as fully active as the wild type under many conditions, exhibits a significant decrease in the midpoint redox potential of heme a relative to Cu(A) (DeltaE(m)) of approximately equal 40 mV, has lowered activity under conditions of high pH or in the presence of a membrane potential, and has a slowed heme a(3) reduction with dithionite. Another mutant, D132A, which strongly inhibits proton uptake from the internal side of the membrane, has <4% of the activity of the wild type and appears to be dependent on proton uptake from the outside. A double mutation, D132A/R481K, is even more strongly inhibited ( approximately 1% of that of the wild type). The more-than-additive effect supports the concept that R481K not only lowers the midpoint potential of heme a but also limits a supply route for protons from the outside of the membrane used by the D132 mutant. The results are consistent with an important role of R481 and heme a/a(3) propionates in proton movement in a reversible exit path.

Animals↗
PubMed1992

3-(2-Carboxyindol-3-yl)propionic acid-based antagonists of the N-methyl-D-aspartic acid receptor associated glycine binding site.

A series of substituted 3-(2-carboxyindol-3-yl)propionic acids was synthesized and tested as antagonists for the strychnine-insensitive glycine binding site of the NMDA receptor. Chlorine, and other small electron-withdrawing substituents in the 4- and 6-positions of the indole ring, greatly enhanced binding and selectivity for the glycine site over the glutamate site of the NMDA receptor; one of the most potent compounds is 3-(4,6-dichloro-2-carboxyindol-3-yl)propionic acid (IC50 = 170 nM; greater than 2100-fold selective for glycine). The importance of a heteroatom NH and the enhancing effect of the propionic acid side chain were demonstrated and are consistent with previous results which suggest the presence of a pocket on the receptor which can accept an acidic side chain. Substitution of a sulfur at C3 led to the most potent compound 3-[(carboxymethyl)thio]-2-carboxy-4,6-dichloroindole (IC50 = 100 nM).

Animals↗
PubMed1980

Chemical modification of the haem propionate of cytochrome c.

The significance of the exposed haem edge in cytochrome c was directly probed by chemically modifying the partially exposed haem propionate in the crevice region around residues threonine-78 and threonine-49. Reaction of tuna heart cytochrome c with a water-soluble carbodi-imide at pH 3.7 in the absence of any added nucleophilic base leads to the covalent addition of substituted N-acylureas to the protein at two sites. One site has been shown to be a haem propionate by isotope-tracer and i.r.-spectral analysis of haem purified from the apoprotein. The other site is aspartial acid-62 on the back of the molecule. The modified cytochrome c demonstrates abnormal properties, including auto-oxidizability, a reduction potential of + 105mV, a reversible transition to a high-spin species below pH 5.3, no 695 nm charge-transfer band in the ferric state and abnormal binding to mitochondrial membranes. The derivative does react with cytochrome oxidase in deoxycholate-treated submitochondrial particles or in purified preparations with a specific activity of 43-65% compared with that obtained with native cytochrome c. The results are consistent with the view that an intact haem crevice is essential for normal values for physiochemical characteristics, but the significant residual enzymic activity suggests that the electron-transfer interface and/or the cytochrome oxidase-binding site cannot be localized solely in the region of the exposed haem propionate.

Amino Acids↗
PubMed1995

Metabolism of [3-13C]pyruvate and [3-13C]propionate in normal and ischaemic rat heart in vivo: 1H- and 13C-NMR studies.

The oxidation of [3-13C]pyruvate and [3-13C]propionate was studied in vivo in infused rats. The infused [3-13C]pyruvate was quickly converted to [3-13C]lactate in the blood, and the [3-13C]lactate formed was well metabolized in both normoxic and ischaemic hearts. Large differences (200-600%) in the 13C enrichment of alanine (C-3) and acetyl-CoA (C-2) compared with lactate (C-3) were found in both normoxic and ischaemic hearts, suggesting that the extracellular [3-13C]lactate preferentially entered a region of the cytoplasm which specifically transfers the labelled pyruvate (formed from [3-13C]lactate) to the mitochondria. The highly enriched mitochondrial pyruvate gave high enrichment in alanine and acetyl-CoA, which was detected by 1H- and 13C-NMR spectroscopy. Ischaemia increased 13C incorporation into the main cytoplasmic lactate pool and decreased 13C incorporation into citric acid cycle intermediates, mainly decreasing the pyruvate anaplerosis. Isoprenaline-induced ischaemia of the heart caused only a slight decrease in pyruvate oxidation. In contrast to the decreased anaplerosis of pyruvate, the anaplerosis of propionate (and propionyl-carnitine) increased significantly in ischaemic hearts, which may contribute to the protective effect of propionyl-carnitine seen in ischaemia. In addition, we found that [3-13C]propionate preferentially labelled aspartate C-3 in rat heart, suggesting incomplete randomization of label in the succinyl-CoA-malate span of the citric acid cycle. These data show that proton observed 13C edited spectroscopic methods, i.e. heteronuclear spin-echo and the one-dimensional heteronuclear multiple quantum coherence sequence, can be successfully used to study heart metabolism in vivo.

Acetyl Coenzyme A↗
PubMed1980

Propionate enhancement of acetoacetate oxidation in perfused rat hearts.

1. Isolated perfused rat hearts, acetoacetate oxidation was significantly enhanced by propionate. 2. No enhancement of acetoacetate oxidation could be observed in vitamin B12-deficient rat hearts when propionate was present. 3. Although the mechanisms of enhancement are not clear, ketone clearance is enhanced by propionate and may provide an insight into the therapy of certain diseases characterized by ketosis.

Acetoacetates↗
PubMedDate not supplied

Effect of supplemental calcium propionate on insulin action to blood glucose metabolism in adult sheep.

An experiment combining a hyperinsulinemic euglycemic clamp procedure of four sequential 2-h periods and an isotope dilution method of [U-13C]glucose determined the effect of supplemental calcium propionate on blood glucose metabolism during insulin and glucose infusions in adult sheep. They were fed lucerne hay cubes and commercial concentrate with and without supplementary calcium propionate (Prop and Cont diets, respectively) in a crossover design for each 21-day period. At the preinfusion period, blood glucose turnover rate (GTR) was greater (P < 0.05) for the Prop diet than for the Cont diet. Blood GTR, endogenous glucose production rate (EGPR) and the ratio of EGPR to blood GTR were greater (P < 0.01, P < 0.05 and P < 0.05, respectively) for the Prop diet than for the Cont diet. Blood GTR and glucose infusion rate (GIR) increased (P < 0.001) and the ratio of EGPR to blood GTR was reduced (P < 0.01) with increased insulin infusion rates. The maximal GIR tended to be (P < 0.10) greater for the Prop diet than for the Cont diet but plasma insulin concentration at half maximal GIR did not differ between diets. It is suggested that in adult sheep, dietary propionate supplementation enhances insulin action on glucose metabolism, however, changes in measures of tissue responsiveness and sensitivity were not significant.

Animal Feed↗
PubMed1988

Plasma insulin and glucose in suckling and ruminating lambs after peroral administration of glucose and propionate.

An identical volume of water solutions: 1) glucose 5.56 mmol/kg b.w., or 2) sodium propionate 5.56 mmol/kg b.w., was given perorally to sucklings (6 weeks) and weaned lambs (10 weeks). The maximum increase of glycemia and the highest insulin concentrations were observed 60-90 min after glucose administration in both groups of lambs. Plasma insulin of suckling and weaned lambs was increased within 60 min after propionate infusion. It can be concluded that propionate is a potent insulin secretagogue in sucklings as well as in ruminating ones. However, glucose is probably the most effective stimulus for insulin release in both groups of lambs.

Administration, Oral↗
PubMedDate not supplied

[Blood propionic acid with hyperammonemic coma].

We report on a mature male newborn who presented clinically on the 2nd day of live with poor feeding and acidotic breathing. Laboratory findings like severe metabolic acidosis, hyperammonemia, hyperglycinemia, ketonuria and elevated urinary excretion of lactate and propionate suggested the presence of organoacidopathia. Propionic acidemia, however could be diagnosed definitively only when the characteristic urinary and blood metabolites were found during the state of a hyperammonemic coma provoked by a fully oral protein regimen. The diagnosis was affirmed by reduced propionate fixation and by reduced propionyl-CoA-carboxylase shown in the patient's skin fibroblasts.

Acidosis↗