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PubMed1997

Lipoxygenase is irreversibly inactivated by the hydroperoxides formed from the enynoic analogues of linoleic acid.

Triple bond analogues of natural fatty acids irreversibly inactivate lipoxygenase during their enzymatic conversion [Nieuwenhuizen, W. F., et al. (1995) Biochemistry 34, 10538-10545]. To gain insight into the mechanism of the irreversible inactivation of soybean lipoxygenase-1, we studied the enzymatic conversion of two linoleic acid analogues, 9(Z)-octadec-9-en-12-ynoic acid (9-ODEYA) and 12(Z)-octadec-12-en-9-ynoic acid (12-ODEYA). During the inactivation process, Fe(III)-lipoxygenase converts 9-ODEYA into three products, i.e. 11-oxooctadec-9-en-12-ynoic acid, racemic 9-hydroxy-10(E)-octadec-10-en-12-ynoic acid, and racemic 9-hydroperoxy-10(E)-octadec-10-en-12-ynoic acid. Fe(II)-lipoxygenase does not convert the inhibitor and is not inactivated by 9-ODEYA. Fe(III)-lipoxygenase converts 12-ODEYA into 13-hydroperoxy-11(Z)-octadec-11-en-9-ynoic acid (34/66 R/S), 13-hydroperoxy11(E)-octadec-11-en-9-ynoic acid (36/64 R/S), 11-hydroperoxyoctadec-12-en-9-ynoic acid (11-HP-12-ODEYA, enantiomeric composition of 33/67), and 11-oxooctadec-12-en-9-ynoic acid (11-oxo-12-ODEYA) during the inactivation process. Also, Fe(II)-lipoxygenase is inactivated by 12-ODEYA. It converts the inhibitor into the same products as Fe(III)-lipoxygenase does, but two additional products are formed, viz. 13-oxo-11(E)-octadec-11-en-9-ynoic acid and 13-oxo-11(Z)-octadec-11-en-9-ynoic acid. The purified reaction products were tested for their lipoxygenase inhibitory activities. The oxo compounds, formed in the reaction of 9-ODEYA and 12-ODEYA, do not inhibit Fe(II)- or Fe(III)-lipoxygenase. The 9- and 13-hydroperoxide products that are formed from 9-ODEYA and 12-ODEYA, respectively, oxidize Fe(II)-lipoxygenase to its Fe(III) state and are weak lipoxygenase inhibitors. 11-HP-12-ODEYA is, however, the most powerful inhibitor and is able to oxidize Fe(II)-lipoxygenase to Fe(III)-lipoxygenase. 11-HP-12-ODEYA is converted into 11-oxo-12-ODEYA by Fe(III)-lipoxygenase. We propose a mechanism for the latter reaction in which Fe(III)-lipoxygenase abstracts the bisallylic hydrogen H-11 from 11-HP-12-ODEYA, yielding a hydroperoxyl radical which is subsequently cleaved into 11-oxo-ODEYA and a hydroxyl radical which may inactivate the enzyme.

Alkynes↗
PubMed2005

Binding of gaseous Fe(III)-heme cation to model biological molecules: direct association and ligand transfer reactions.

The binding of a variety of ligands with Fe(III)-heme(+) ion, prosthetic group of heme proteins, has been studied in the gas phase by ESI-FT-ICR mass spectrometry. The ligands have been selected among substrate molecules of heme proteins (e.g., NO, nitroso compounds) or among model compounds acting for the functional groups that are present in the protein backbone (e.g., amines, thioethers, nitriles, ketones, amides, etc.). Both the kinetic and the thermodynamic features of the addition reactions are reported. Fe(III)-heme(+) ions react faster with lone pair donor ligands as the reaction becomes increasingly thermodynamically favored (higher heme cation basicity of the ligand, HCB, namely -DeltaG degrees for the ligand addition reaction). In turn HCBs correlate in general with the gas phase basicity toward the proton of the various ligands. A ligand addition equilibrium is established with weaker ligands, methanol, acetonitrile and acetone, yielding absolute HCB values, whereas ligand transfer equilibriums allowed a scale of relative (and absolute) HCBs to be constructed. NO displays exceptional binding properties towards Fe(III)-heme(+), unrelated to the low gas phase basicity toward the proton of this molecule, which is clearly the basis for the paramount role of heme proteins in NO binding and regulation.

Cations↗
PubMed2003

Effects of Ag(I), Au(III), and Cu(II) on the reductive dechlorination of carbon tetrachloride by green rust.

Green rusts (GRs), mixed iron(II)/iron(III) hydroxide minerals found in many suboxic environments, have been shown to reduce a range of organic and inorganic contaminants, including several chlorinated hydrocarbons. Many studies have demonstrated the catalytic activity of transition metal species in the reduction of chlorinated hydrocarbons, suggesting the potential for enhanced reduction by GR in the presence of an appropriate transition metal catalyst. Reductive dechlorination of carbon tetrachloride (CT) was examined in aqueous suspensions of GR amended with Ag(I), Au(III), or Cu(II). The CT reduction rates were greatly increased for systems amended with Cu(II), Au(III), and Ag(I) (listed in order of increasing rates) relative to GR alone. Observed intermediates and products included chloroform, dichloromethane, chloromethane, methane, acetylene, ethene, ethane, carbon monoxide, tetrachloroethene, and various nonchlorinated C3 and C4 compounds. Product distributions for the reductive dechlorination of CT were highly dependent on the transition metal used. A reaction pathway scheme is proposed in which CT is reduced primarily to methane and other nonchlorinated end products, largely through a series of one-electron reductions forming radicals and carbenes/carbenoids. Recently, X-ray absorption fine structure analysis of aqueous GR suspensions amended with Ag(I), Au(III), or Cu(II) showed that the metals were reduced to their zerovalent forms. A possible mechanism for CT reduction is the formation of a galvanic couple involving the zerovalent metal and GR, with reduction of CT occurring on the surface of the metal and GR serving as the bulk electron source. The enhanced reduction of CT by GR suspensions amended with Ag(I), Au(III), or Cu(II) may prove useful in the development of improved materials for remediation of chlorinated organic contaminants.

Carbon Tetrachloride↗
PubMed1983

Development of a blood-free Campylobacter medium: screening tests on basal media and supplements, and the ability of selected supplements to facilitate aerotolerance.

The capacity of six basal media to support the growth of thermophilic campylobacters was tested. The most successful was Nutrient Broth No. 2 (Oxoid) solidified with New Zealand agar but it gave at best only a 9% recovery rate. Various blood products, iron compounds, detoxifying agents, reducing agents, growth stimulants and an antimetabolite were added to the selected basal medium and counts of inoculated organisms were compared with counts on basal medium containing 5% lysed horse blood. Of 22 supplements tried only blood, Fildes' peptic digest of blood, heamatin, iron salts, charcoal, sodium metabisulphite and sodium pyruvate greatly improved the basal medium. The ability of these supplements used singly and in combinations to facilitate aerotolerance of campylobacters was investigated. Two aspects of aerotolerance were tested; (a) the ability of the supplements to sustain the viability of campylobacters seeded onto culture plates left on the bench for up to 6 h before microaerobic incubation; and (b) the ability of the supplements to facilitate the growth of campylobacters at increasing oxygen tension (6, 10 and 17% oxygen). A combination of 0.4% charcoal, 0.025% ferrous sulphate and 0.025% sodium pyruvate was found to be as effective as blood in both tests.

Campylobacter↗
PubMed2004

Extractive spectrophotometric methods for the determination of doxepin hydrochloride in pharmaceutical preparations using titanium (IV) and iron (III) thiocyanate complexes.

Two simple, precise, and accurate extractive spectrophotometric methods have been developed for the determination of doxepin hydrochloride in pharmaceutical preparations. The methods are based on the formation of ion association complexes of doxepin with titanium (IV) and iron (III) thiocyanate complexes in acidic medium. The produced compounds are insoluble in water but well soluble in some organic solvents. They are extracted with mixtures of butyl alcohol-chloroform (2:3, v/v) and (1:4, v/v) and measured spectrophotometrically at 400 and 490 nm for DOX-Ti-SCN and DOX-Fe(III)-SCN methods, respectively. Beer's law was obeyed in the concentration ranges of 5-50 and 3-30 microg/ml with molar absorptivity of 7.12 x 10(3) and 1.36 x 10(4) l mol(-1) cm(-1) for DOX-Ti-SCN and DOX-Fe-SCN systems, respectively. The proposed methods have been successfully applied for the analysis of the drug in dosage forms. No interference was observed from common pharmaceutical adjuvants. The methods have been also used for the determination of the drug in the presence of its degradation product. Statistical comparison of the obtained results with the reference methods shows excellent agreement and indicates no significant difference in accuracy and precision.

Antidepressive Agents, Tricyclic↗
PubMed2004

Ferromagnetic interaction in mu1,3-cyanamido-derived copper(II) cryptates.

The reaction of dinuclear copper(II) cryptates with calcium cyanamide, CaNCN, and sodium dicyanamide, Na[N(CN)(2)] results in dinuclear compounds of formulae [Cu(2)(HNCN)(R3Bm)](ClO(4))(3) (1), [Cu(2)(dca)(R3Bm)](ClO(4))(3)4H(2)O (2), and [Cu(2)(NCNCONH(2))(R3Bm)](CF(3)SO(3))(3) (3), in which R3Bm=N[(CH(2))(2)NHCH(2)(C(6)H(4)-m)CH(2)NH(CH(2))(2)](3)N and dca=dicyanamido ligand (NCNCN(-)). The X-ray diffraction analysis reveals for both 1 and 3 a dinuclear entity in which the copper atoms are bridged by means of the -NCN- unit. The molar magnetic susceptibility measurements of 1-3 in the 2-300 K range indicate ferromagnetic coupling. The calculated J values, by using theoretical methods based on density functional theory (DFT) are in excellent agreement with the experimental data. Catalytic hydration of a nitrile to an amide functional group is assumed responsible for the formation of 3 from a mu(1,3)-dicyanamido ligand.

Cations↗
PubMed2004

Desulfosporomusa polytropa gen. nov., sp. nov., a novel sulfate-reducing bacterium from sediments of an oligotrophic lake.

Five strains of sulfate-reducing bacteria were isolated from the highest positive dilutions of a most probable number (MPN) series supplemented with lactate and inoculated with sediments from the oligotrophic Lake Stechlin. The isolates were endospore-forming and were motile by means of laterally inserted flagella. They stained Gram-negative and contained b-type cytochromes. CO difference spectra indicated the presence of P582 as a sulfite reductase. Phylogenetic analyses of the 16S rDNA sequences revealed that the isolates were very closely affiliated with the genus Sporomusa. However, sulfate and amorphous Fe(OH)(3), but not sulfite, elemental sulfur, MnO(2), or nitrate were used as terminal electron acceptors. Homoacetogenic growth was found with H(2)/CO(2) gas mixture, formate, methanol, ethanol, and methoxylated aromatic compounds. The strains grew autotrophically with H(2) plus CO(2) in the presence or absence of sulfate. Formate, butyrate, several alcohols, organic acids, carbohydrates, some amino acids, choline, and betaine were also utilized as substrates. The growth yield with lactate and sulfate as substrate was 7.0 g dry mass/mol lactate and thus two times higher than in sulfate-free fermenting cultures. All isolates were able to grow in a temperature range of 4-37 degrees C. Physiologically and by the presence of a Gram-negative cell wall, the new isolates resemble known Desulfosporosinus species. However, phylogenetically they are affiliated with the Gram-negative genus Sporomusa belonging to the Selenomonas subgroup of the Firmicutes. Therefore, the new isolates reveal a new phylogenetic lineage of sulfate-reducing bacteria. A new genus and species, Desulfosporomusa polytropa gen. nov., sp. nov. is proposed.

Bacterial Typing Techniques↗
PubMed2006

Design of molecular wires based on supramolecular structures for application in glucose biosensors.

In the present work, the synthesis and the spectroelectrochemical characterization of a novel iron compound derived of tetra-2-pyridyl-1,4-pyrazine (TPPZ) with hexacyanoferrate species forming a very stable supramolecular complex in the presence of polypyrrole (PPY) matrix, is described. The hybrid material has shown excellent catalytic activity towards H(2)O(2) detection that makes it suitable for being used as redox mediator in a glucose biosensor. The hybrid FeTPPZFeCN/PPY film presents satisfactory detection limits and high sensitivity for H(2)O(2) in the presence of K(+) or Na(+) ions. For the glucose biosensor, a linear range up to 1.1 mmoll(-1) of glucose was observed with no interferences. In this case, the sensitivities obtained were 7.88 and 5.90 microAmmol(-1)lcm(-2) in phosphate buffer or NaCl solutions, respectively. The good sensitivity is related to the presence of a high-dimensional structure based on polypyridine type ligands providing an "electron antennae effect" facilitating electron tunneling between the protein and the electrode.

Biosensing Techniques↗
PubMed1993

Is superoxide an initiator of microsomal lipid peroxidation?

The effects of "pro-oxidant" quinones, doxorubicin, Fe(3+)-ADP-doxorubicin complex, and menadione, as well as of free radical scavengers possessing superoxide-dismuting activities, Fe(3+)-rutin and Cu(2+)-rutin, on superoxide production and lipid peroxidation in rat liver microsomes have been studied. All quinone compounds efficiently suppressed lucigenin-dependent chemiluminescence produced in NADPH-dependent microsomal lipid peroxidation, but exhibited different effects on cytochrome c reduction: doxorubicin and Fe(3+)-ADP-doxorubicin weakly inhibited and menadione enhanced it. In accord with previous findings, menadione inhibited malondialdehyde (MDA) formation in microsomes, while Fe3-ADP-doxorubicin enhanced it. Efficiency of inhibition of MDA formation by the Fe(3+)-rutin and Cu(2+)-rutin complexes correlated well with their superoxide-dismuting activities in contrast to the findings obtained in nonenzymatic liposomal peroxidation, where the formation of superoxide ion is not expected. On these grounds, we propose that superoxide ion is an obligatory initiation species in microsomal lipid peroxidation; the effects of pro-oxidant quinones on lipid peroxidation depends on their ability to chelate iron ions and not on their redox-cycling activities.

Acridines↗
PubMed2006

Desulfovibrio frigidus sp. nov. and Desulfovibrio ferrireducens sp. nov., psychrotolerant bacteria isolated from Arctic fjord sediments (Svalbard) with the ability to reduce Fe(III).

Strains 18T, 61T and 77 were isolated from two permanently cold fjord sediments on the west coast of Svalbard. The three psychrotolerant strains, with temperature optima at 20-23 degrees C, were able to grow at the freezing point of sea water, -2 degrees C. The strains oxidized important fermentation products such as hydrogen, formate and lactate with sulfate as the electron acceptor. Sulfate could be replaced by sulfite, thiosulfate or elemental sulfur. Poorly crystalline and soluble Fe(III) compounds were reduced in sulfate-free medium, but no growth occurred under these conditions. In the absence of electron acceptors, fermentative growth was possible. The pH optimum for the strains was around 7.1. The DNA G+C contents were 43.3 and 42.0 mol% for strains 18T and 61T, respectively. Strains 18T, 61T and 77 were most closely related to Desulfovibrio hydrothermalis (95.0-95.7 % 16S rRNA gene sequence similarity). Strains 18T and 77, exhibiting 99.9 % sequence similarity, represent a novel species for which the name Desulfovibrio frigidus sp. nov. is proposed. The type strain is strain 18T (=DSM 17176T = JCM 12924T). Strain 61T was closely related to strains 18T and 77 (97.6 and 97.5 % 16S rRNA gene sequence similarity), but on the basis of DNA-DNA hybridization strain 61T represents a novel species for which the name Desulfovibrio ferrireducens sp. nov. is proposed. The type strain is strain 61T (=DSM 16995T = JCM 12925T).

Arctic Regions↗
PubMed2006

Iron ions derived from the nitric oxide donor sodium nitroprusside inhibit mineralization.

Sodium nitroprusside (SNP) is a nitric oxide (NO) donor drug, which is therapeutically used as a vasodilating drug in heart transplantations. In our previous study it was found that SNP at a concentration of 100 microM inhibited mineralization in a cell culture system, indicating that the beneficial effects of this drug may also include inhibition of vascular calcification. The aim of this study was to investigate which bioactive compounds generated from SNP inhibit mineralization. ATDC5 cells were grown for 14 days and mineralization was induced by addition of 5 mM phosphate for 24 h. Mineralization was determined by staining precipitated calcium with an alizarin red stain. It was found that the NO donors S-nitrosoglutathione and S-nitroso-N-acetylpenicillamine were not able to inhibit mineralization and NO scavengers could not antagonize the inhibiting effect of SNP on mineralization. The iron chelator deferoxamine (200 microM) antagonized the inhibiting effect on mineralization mediated by SNP and ammonium iron sulfate inhibited mineralization in a dose-dependent manner (10-100 microM). Furthermore, iron ions (30 microM) were detected to be released from SNP in the cell culture. These data show that the iron moiety of sodium nitroprusside, rather than nitric oxide inhibits mineralization.

Animals↗
PubMed1999

Mechanism of inhibition of porcine leukocyte 12-lipoxygenase by the isoform-specific inhibitor 4-(2-oxapentadeca-4-yne)phenylpropanoic acid.

The mechanism of inhibition of porcine leukocyte 12-lipoxygenase by 4-(2-oxapentadeca-4-yne)phenylpropanoic acid (OPP) was investigated. This compound is selective for the leukocyte form of the 12-lipoxygenase and inhibits the purified recombinant enzyme with an IC(50) value of approximately 2 microM. OPP induced a concentration-dependent lag phase in the oxygenation of arachidonic acid and decreased the maximal rate of reaction. Addition of the fatty acid hydroperoxide 13(S)-hydroperoxyoctadecadienoic acid (13-HPODE) to the reaction greatly reduced the OPP-induced lag. Lineweaver-Burk analysis of the effect of OPP on 12-lipoxygenase kinetics with arachidonic acid indicated that it was a mixed-type inhibitor. OPP was not metabolized by 12-lipoxygenase as evidenced by its quantitative recovery from incubations with stoichiometric amounts of enzyme and 13-HPODE or arachidonic acid. OPP inhibited the pseudoperoxidase activity of the enzyme with 13-HPODE and the reducing agent, BWA137C. Lineweaver-Burk analysis of the effect of OPP on pseudoperoxidase kinetics suggested that OPP was competitive with 13-HPODE. Single-turnover experiments indicated that OPP inhibited the reduction of 13-HPODE by a stoichiometric amount of ferrous 12-lipoxygenase. Addition of 13-HPODE shortened the OPP-induced lag phase but did not affect the maximal rate of enzyme activity. In addition, OPP had no effect on total product formation in either the presence or the absence of 5 microM 13-HPODE when the reaction was allowed to go to completion. All of these observations are consistent with a model for inhibition of 12-lipoxygenase activity in which OPP slows the oxidation of the inactive ferrous enzyme to the active ferric enzyme and competes with arachidonic acid for the ferric enzyme.

Animals↗
PubMed2005

Investigations into the metal species of the homogeneous iron(III) catalyzed Michael addition reactions.

An investigation into the species formed in the first step of the solvent free homogeneous Michael reaction of alpha,beta-unsaturated ketones with 2-oxocyclopentanecarboxylate (1) is presented. This reaction is catalyzed by FeCl(3).6H(2)O (2) and Fe(ClO(4))(3).9H(2)O (3). EXAFS, XANES, Raman and UV-Vis studies were carried out to explain the experimentally found higher catalytic activity of Fe(ClO(4))(3).9H(2)O (3) compared to FeCl(3).6H(2)O (2). A very intense pre-edge peak is found for a 1.6 mol% solution of FeCl(3).6H(2)O (2) in 1, suggesting a tetrachloroferrate(III) compound to be present in this solution. This is proved by UV-Vis and Raman spectroscopy. The counterion of this anionic complex is an octahedral [Fe(III)(1-H)(2)(H2O2)](+) complex with two deprotonated 2-oxocyclopentanecarboxylate (1) as the chelating ligand, (1-H)(-), as suggested by the examination of the XANES region, the obtained coordination numbers from the EXAFS analysis and by UV-Vis and Raman spectroscopies. In summary, the anion-cation species [Fe(III)Cl(4)](-)[Fe(III)(-H)(2)(H2O2)](+) is formed with FeCl(3).6H(2)O (2), whereas in the case of Fe(ClO(4))(3).9H(2)O (3) XAFS, Raman and UV-Vis investigations suggest the presence of a complex of the form [Fe(III)(1-H)(2)(H2O2)](+)[ClO(4)](-). The obtained results are discussed to explain the reduced catalytic activity of FeCl(3).6H(2)O (2) in comparison to Fe(ClO(4))(3).9H(2)O (3).

Catalysis↗
PubMedDate not supplied

Detection of the production of reactive oxygen species by neutrophils in whole blood: modulation by adamantanes and triggering by Fe(3+)-ions.

Using indicators for the production of reactive oxygen species (ROS) such as the a) OH-radical type (alpha-keto-gamma-methiolbutyric acid, KMB) or b) hypochlorous acid (1-amino-cyclopropyl-1-carboxylic acid, ACC) neutrophil activities can be both quantified and differentiated in whole blood via ethene production. Ethene is trapped in the head space of blood samples incubated in the presence of zymosan and the respective indicators, KMB or ACC. This procedure allows the detection of effects of aminoadamantanes (AAD) such as amantadine or memantine, compounds frequently used for the treatment of Morbus Parkinson and Morbus Alzheimer. In this report we describe the detection of OH.-type oxidants produced by isolated activated neutrophils and whole blood. Immunomodulatory activities of AAD are deduced from the following observations: AAD-stimulated ethene formation from (KMB) as an indicator for production of OH.-type reactive oxygen species by zymosan-stimulated neutrophils ("respiratory burst") is detectable with isolated neutrophils. In whole blood, however, this reaction is only measurable in the presence of Fe-EDTA-complex. Stimulating effects of AAD are observed within a concentration range between 10(-8) and 10(-4) M with a maximum at 1 microM. Ethene release from (ACC) as indicator for the myeloperoxidase reaction after degranulation is not stimulated by AAD but inhibited at concentrations higher than 100 microM. The presented results suggest that submicromolar concentrations of AAD only stimulate the respiratory burst and apparently not degranulation of zymosan-prestimulated polymorphonuclear neutrophils (PMN).

Adamantane↗
PubMed1999

Formation and characterization of iron-oligonucleotide complexes with matrix-assisted laser desorption/ionization fourier transform ion cyclotron resonance mass spectrometry.

Iron-containing oligonucleotide negative ions can be generated by matrix-assisted laser desorption/ionization from a stainless steel target disk (by either defocusing the laser beam or by mixing iron salts such as FeCl3 with the matrix compound during the sample preparation). High resolution mass measurements reveal the presence of both Fe2+ (as M + Fe - 3H)- and Fe3+ (as M + Fe - 4H)- in the metal-oligonucleotide ions. The presence of Fe3+ is unexpected, and must involve replacement of protons from the nucleic bases or ribose groups as well as the phosphate groups of the oligonucleotides. Inspection of a range of small oligonucleotides and mononucleotides reveals that the presence of both Fe2+ and Fe3+ in the iron-biomolecule complexes is dependent on the number of acidic hydrogens that can be replaced in the oligonucleotide or nucleotide. Collisional dissociation of several metal-tetranucleotide ions revealed that the presence of the iron ion alters the fragmentation observed. The iron atom was observed to be present in all of the fragment ions, and, whenever possible, seemed to enhance the abundance of fragment ions containing both iron and a guanine nucleic base. These results suggest that iron may serve as a useful probe for characterizing phosphorylated biomolecules.

Chlorides↗
PubMed2005

Glial cell line-derived neurotrophic factor-conjugated nanoparticles suppress acquisition of cocaine self-administration in rats.

The neurotrophic factor glial cell line-derived neurotrophic factor (GDNF) may have therapeutic potential for preventing and treating cocaine addiction. Previously, we found that transplantation of a GDNF-expressing astrocyte cell line into the striatum and nucleus accumbens attenuates cocaine-seeking behavior in Sprague-Dawley rats. However, as a potential treatment for humans, cell transplantation presents several technical and ethical complications. Nanoparticulate systems are a safe and effective method for introducing exogenous compounds into the brain. Therefore, we examined the effect of GDNF-conjugated nanoparticles microinjected into the striatum and nucleus accumbens on cocaine self-administration in rats. GDNF-conjugated nanoparticles blocked the acquisition of cocaine self-administration compared to control treatments. Furthermore, a cocaine dose response demonstrated that decreased lever response in rats that received GDNF-conjugated nanoparticles persisted after substitution with different cocaine doses. This effect is not due to a non-specific disruption of locomotor or operant behavior, as seen following a water operant task. The current study is one of the first demonstrations that drug-conjugated nanoparticles may be effective in treating brain disorders. These findings suggest that GDNF-conjugated nanoparticles may serve as a novel potential treatment for drug addiction.

Animals↗
PubMed2000

Iron supplementation in preterm infants: a study comparing the effect and tolerance of a Fe2+ and a nonionic FeIII compound.

The more widely used divalent forms of iron (Fe2+) supplementation often lead to gastrointestinal symptoms in preterm infants although little is known about the use of nonionic trivalent iron preparations (FeIII) in these patients. It is especially under this nonionic form that dietary iron is available. For this reason, a randomized controlled study was undertaken to compare the efficacy and the extent of possible side effects in two groups of preterm infants. In one group, the elemental iron was given in the Fe2+ form, while the other group received a nonionic trivalent iron (FeIII) complexed with polysaccharides of low molecular weight. Both groups received 7.5 mg elemental iron daily. Measured parameters in the two study groups did not differ significantly throughout the study period of 14 weeks. Both forms of iron supplementation were well tolerated. However, vomiting, diarrhea, or constipation occurred slightly more often in the group receiving iron supplementation in the Fe2+ form without reaching statistical difference. The authors found a nonionic trivalent polysaccharide-iron complex given as iron supplementation as effective as the generally more favored ferrous sulphate. Since iron therapy is mandatory in the preterm infant, the use of trivalent iron complexes can be considered as a good alternative.

Dietary Supplements↗
PubMed1984

Effects of antiperoxidants on FeCl2-induced lipid peroxidation and focal edema in rat brain.

Head trauma with contusion or cortical laceration and hemorrhage causes focal edema with encephalomalacia and gliosis. Because cerebral hemorrhage ultimately results in deposition of heme compounds and iron into the neuropil, we injected an aqueous solution of iron salts to simulate the decompartmentalization of iron after trauma. We pretreated animals with saline or with 600 mg/kg alpha-tocopherol plus 5 ppm selenium added to the drinking water. Formation of lipid peroxidation products was significantly inhibited within the iron injection site in the antiperoxidant-pretreated rats at 30, 60, and 120 min after injection of iron into the isocortex. The antiperoxidants failed to prevent formation of focal brain edema at the injection site between 1 and 8 h after injection; however, significantly less edema was present in the alpha-tocopherol + selenium-pretreated animals 24 and 48 h after injection. The efficacy of antiperoxidants in preventing lipid peroxidation, and enhancing the resolution of ferrous-induced focal brain edema suggest that tocopherol + selenium administration caused free radical quenching and termination of lipid peroxidation, and increased membrane stabilization, an effect similar to the action of glucocorticoids.

Animals↗