Reduction Of Tetrazolium Salt Research Articles

Colorimetric determination of xanthine dehydrogenase by tetrazolium reduction

1. (1) Xanthine dehydrogenase can be determined colorimetrically or spectrophotometrically by means of reduction of Nitro-BT tetrazolium salt as electron acceptor. The method is about eight times more sensitive than the usual photometric assay. 2. (2) The reaction rate is enhanced by the addition of gelatin, phenazine methosulfate, and EDTA. 3. (3) The method can be readily adapted to the colorimetric assay of xanthine or hypoxanthine.

The enzymic estimation of glutamate and glutamine.

A method of estimating glutamic acid is described, based on its dehydrogenation by glutamate dehydrogenase coupled, by means of N-methylphenazine methosulphate, to the reduction of tetrazolium salts. The method is suitable for the estimation of 0-0.3mumole of glutamic acid. The response is linear, but not stoicheiometric: possible reasons for this are discussed. If suitable precautions are taken, the use of a partially purified preparation of glutaminase makes it possible to estimate glutamine also.

Reduction of tetrazolium salts catalyzed by soluble diaphorase in rat liver and embryos of Vicia faba

The presence of two diaphorases has been shown in rat liver and embryos of Vicia fdba. One of these, the NAD(P)H tetrazolium reductase, was firmly bound in the section and was not lost into the incubation medium under conditions of histochemical assay The second diaphorase (soluble diaphorase) was lost from the section into the incubation medium during the first five minutes of incubation. This soluble diaphorase from both rat liver and embryos of V. faba is capable of transferring electrons from NAD(P)H to MTT, INT, NBT and TNBT, but not to tellurite, TTC, BT and NT. The behaviour of the soluble diaphorase in histochemical reactions involving tetrazolium salts as electron acceptors is discussed.

Use of tetrazolium salts for electron transport studies in meningopneumonitis. I. Reduced nicotinamide adenine dinucleotide system.

Allen, Emma G. (Downstate Medical Center, Brooklyn, N.Y.). Use of tetrazolium salts for electron transport studies in meningopneumonitis. I. Reduced nicotinamide adenine dinucleotide system. J. Bacteriol. 90:1505-1512. 1965.-Purified preparations of meningopneumonitis virus (MP) prepared from allantoic fluids of infected chick embryo reduce several tetrazolium salts in the presence of reduced nicotinamide adenine dinucleotide under both aerobic and anaerobic conditions. The pattern of reduction by MP differs from that seen in normal allantoic membrane homogenates, and is inhibited by several cations but not by KCN, atabrine, amytal, antimycin A, or 2,3-dimercaptopropanol (BAL). The reduction of cytochrome c by purified preparations of MP differs from its reduction of tetrazolium salts in that the cytochrome reaction is completely inhibited by BAL and partially inhibited by amytal, atabrine, and antimycin A. The cytochrome reductase of normal allantoic membrane preparations is completely inhibited by each of these compounds.

EFFECT OF PHENAZINE-METHOSULPHATE ON THE HISTOCHEMICAL LOCALIZATION OF LACTATE DEHYDROGENASE.

THE histochemical reaction for the localization of lactate dehydrogenase (LDH) is a multi-step reaction. The reduction of tetrazolium salts in tissue sections cannot be accomplished directly by LDH but only by means of the so-called tissue NADH-diaphorase1. Unfortunately, tissue diaphorases are not uniformly distributed in all tissues, cells or sub-cellular structures. The absence of these enzymes in certain places is therefore a limiting factor for the determination of LDH activity in tissue sections. Thus, in order to localize LDH at sites where no diaphorases are present, the use of an electron carrier seemed necessary.

SUBSTRATE INHIBITION OF TETRAZOLIUM SALT REDUCTION IN DARK ADAPTED RETINAE.

SUBSTRATE INHIBITION OF TETRAZOLIUM SALT REDUCTION IN DARK ADAPTED RETINAE.

REDUCTION SITES OF TETRAZOLIUM SALTS AND TELLURITE IN CLOSTRIDIUM BOTULINUM AND CLOSTRIDIUM TETANI

Employing ultrathin sectioning and negative staining techniques, the reduction sites of tetrazolium salts (nitro blue tetrazolium=NBT, and triphenyl tetrazolium chloride=TTC) and of potassium tellurite in Clostridium botulinum and Cl. Tetani, were examined electron-microscopically. NBT and TTC were reduced to their formazans on or near the intracytoplasmic membrane system (ICMS) and the cytoplasmic membrane. It was presumed that in ultrathin sectioned preparations, owing to the dissolution of formazans in alcohol during the dehydration process, the sites of formazan deposition were seen as electron-transparent spaces among or around the unit membrane elements of the ICMS; moreover, a high tendency the cell wall to detach from the cytoplasmic membrane was noticed.Potassium tellurite appeared to be reduced mainly on or near the cytoplasmic membrane, but not on the ICMS. This result indicates that the sites of tellurite reduction do not necessarily coincide with those of reduction of tetrazolium salts.

A model for NADH-tetrazolium reductase. Histochemical implications of light-induced electron transfer in NADH-riboflavin-tetrazolium complexes.

In the presence of light, reduced nicotinamide adenine dinucleotide (NADH) and riboflavin formed a complex which was able to reduce certain tetrazolium salts. Neither NADH (10−3 M) nor riboflavin (10−4 M) alone was able to induce tetrazolium reduction in the presence of oxygen, but in a nitrogen atmosphere photoreduction of riboflavin induced reduction of tetrazolium salts. Only electrophilic nitro and thiazolyl substituted tetrazolium salts with more positive redox potentials were reduced by the NADH-riboflavin complex, and only monoformazans were produced from the ditetrazolium salts. The reduction kinetics of these tetrazolium salts are given, and the spectral area capable for induction of electron transfer in the NADH-riboflavin complex is screened. It is concluded that the electron transfer in flavin nucleotide dependent dehydrogenase systems will probably proceed without direct interference with the apoenzyme. This may have practical implications for the histochemistry of tetrazolium reductases especially as regards fixation. The catalytic action of light on tetrazolium reduction should also be taken into consideration when tetrazolium salts are used as electron acceptors in a histochemical reaction.

Nonketol Reduction of Tetrazolium Salts in Pharmaceutical Analysis

Nonketol compounds of pharmaceutical interest have been tested for reduction of tetrazolium salts; the quantitative applications of these reactions have been evaluated. Nonketol compounds of pharmaceutical interest have been tested for reduction of tetrazolium salts; the quantitative applications of these reactions have been evaluated.

DETECTION OF TRIOSEPHOSPHATE ISOMERASE AFTER ELECTROPHORESIS.

BY coupling enzymes to the reduction of a tetrazolium salt, dehydrogenases can be located on electrophoresis strips, and several have been shown to consist of more than one protein component1,2. It is possible to detect other enzymes if their action leads to the formation of a compound which can be oxidized by a suitable enzyme in the incubation mixture. In this way triosephosphate isomerase (TPI) has been located by coupling it with phosphoglyceraldehyde dehydrogenase.

A TETRAZOLIUM SALT REDUCTION METHOD FOR DEMONSTRATING LIPOPROTEINS IN TISSUE SECTIONS

A histochemical method demonstrating lipoprotein, depending on the reaction between choline, ethanolamine and serine, and hydroquinone with consequent reduction of tetrazolium salts is described. In vitro tests supporting the chemistry of the reaction are given. The role of this phenomenon in relation to histochemical aspects of the dehydrogenase reactions is discussed.

Reactions of corticosteroids with tetrazolium salts on paper chromatograms

Reduction of blue tetrazolium and other tetrazolium salts by corticosteroids on paper chromatograms gave rise to two formazan fractions, the amounts of which depended on the conditions employed. Evidence is presented that these fractions are not due to impurities. A hypothetical scheme for the reduction of blue tetrazolium and other ditetrazolium salts is given.

Histochemical Studies on Nonspecific Reduction of Tetrazolium Salts in Tissue Sections

Histochemical Studies on Nonspecific Reduction of Tetrazolium Salts in Tissue Sections

REDUCTION OF TETRAZOLIUM SALTS TO FORMAZANS IN FUSOBACTERIUM POLYMORPHUM

The sites of reduction of tetrazolium salts in cells of a strain of Fusobacterium Polymorphum was investigated by means of light microscopy and electron microscopy. The formazans of triphenyltetrazolium chloride were demonstrated to occur as relatively large crystal-shaped depositions in the cytoplasm. As these granules, usually a few in number, seemed to be formed secondarily by the intracellular aggregation of small granules primarily formed in the cytoplasm, it was almost impossible to localize the initial sites of TTC reduction in the cytoplasm. On the contrary, nitrobluetetrazolium formazans were proved to deposit very close to the cytoplasmic membrane and the intracytoplasmic membrane system. These observations strongly suggest that the site of oxidation-reduction activity may be associated with the cytoplasmic membrane and the intracytoplasmic membrane system which have recently been found in various Actinomycetes and Eubacteria.

Oxidative histochemistry of reactive astrocytes.

In the present report the results of a morphologic histochemical study of oxidative enzymes in reactive astrocytes will be presented. This investigation was undertaken as an effort to determine whether reactive astrocytes show a different pattern of enzymatic activities from normal cells and if so, the duration of such changes. For this purpose morphologic histochemical procedures were chosen since brain tissue is composed of many different cell types and major biochemical changes occurring in one cell type can be easily overlooked by classical methods of gross analysis. Recent advances in tetrazolium salt techniques have made it possible to study a number of oxidative enzymes in histologic sections. Many colorless, or near colorless, water-soluble tetrazolium salts can serve as hydrogen acceptors in a number of oxidative enzymatic reactions, yielding highly colored insoluble formazan precipitates at the site of enzymatic activity.1-5In the present work techniques employing tetrazolium salt reduction have

Species differentiation of group D streptococci.

Three hundred and fourteen strains of group D streptococci were studied by means of a number of tests. The majority of the strains were identified as Streptococcus faecalis (83 strains), Streptococcus faecium (131 strains), or Streptococcus bovis (32 strains). Several strains (47 or nearly 15%) either shared characteristics of two species or were completely atypical. S. faecalis and S. bovis were more easily identified than S. faecium, which is not sharply defined from the other species and could be subdivided into several fermentative types on the basis of fermentation of arabinose, mannitol, sorbitol, glycerol, and sucrose. The value of some characteristics in species identification is discussed. Growth in the presence of potassium tellurite 1:2,500 and in the presence of 6.5% NaCl and fermentation of arabinose, glycerol, and raffinose are very important tests for the identification of the three species. The reduction of tetrazolium salts, the reduction of litmus milk, and the fermentation of sorbitol may serve as complementary tests for the same purpose. For the differentiation of these three species the "pattern of reactions" is more important than single tests.

Species Differentiation of Group D Streptococci

Three hundred and fourteen strains of group D streptococci were studied by means of a number of tests. The majority of the strains were identified as Streptococcus faecalis (83 strains), Streptococcus faecium (131 strains), or Streptococcus bovis (32 strains). Several strains (47 or nearly 15%) either shared characteristics of two species or were completely atypical. S. faecalis and S. bovis were more easily identified than S. faecium, which is not sharply defined from the other species and could be subdivided into several fermentative types on the basis of fermentation of arabinose, mannitol, sorbitol, glycerol, and sucrose. The value of some characteristics in species identification is discussed. Growth in the presence of potassium tellurite 1:2,500 and in the presence of 6.5% NaCl and fermentation of arabinose, glycerol, and raffinose are very important tests for the identification of the three species. The reduction of tetrazolium salts, the reduction of litmus milk, and the fermentation of sorbitol may serve as complementary tests for the same purpose. For the differentiation of these three species the "pattern of reactions" is more important than single tests.

Studies on the Reduction of Tetrazolium Salt by Plant Tissues

Studies on the Reduction of Tetrazolium Salt by Plant Tissues

Studies on the Reduction of Tetrazolium Salt by Plant Tissues

1. A colorimetric method to determine the activity of TTC reduction in tissue slices of bean embryo was established.2. The reduction proceeded at constant rate under aerobic condition as well as under anaerobic condition.3. The reduction rate increased with reaction temperature till 50°C. The pH of surrounding medium influenced the reaction rate slightly.4. Plasmolysis with sugar solutions depressed the reaction, whereas urea favoured it at high concentration. Deplasmolysis prior to the reaction stimulated the reduction.5. Plasmolysis with inorganic salt solutions influenced the reduction in different degrees. At the plasmolysing concentrations, anions affected the reaction in the order of the lyotropic series. No serious order was observed among cations.6. Relationship between the activity of the reaction and site of the enzymes in the cytoplasm and its colloidal state was discussed.

Alterations in the oxidative metabolism of rats with induced tolerance: in vitro study of diaphragm.

Oxidative metabolism of diaphragms from endotoxin- and trauma-tolerant rats was investigated, utilizing the reduction of tetrazolium salt. It was found that diaphragms from normal and stress-tolerant animals did not differ in "oxidative performance" (activity in the absence of the redox dye phenazine methosulfate). However, diaphragms from tolerant animals exhibited a highly significant enhancement in "oxidative potential" (activity in the presence of phenazine methosulfate). This change was apparently not precipitated by adjustments in circulatory dynamics, nor was it related to reticuloendothelial stimulation. The suggestion is made that the effects observed may develop through the secondary release of endogenous epinephrine. Evidence is presented suggesting that the enhancement of "oxidative potential" exhibited by the parenchymal tissues of tolerant animals represents an adaptation in metabolism whereby pools of potentially oxidizable foodstuffs are stockpiled.