Effect of sodium thiosulfate on viable areas of the pancreas in experimental pancreatitis

Experimental pancreatitis in white rats is marked by stromal edema, dystrophic changes of acinar cells, with intracellular edema in an intact part of the pancreas. Subsequently the acinar cells undergo intracellular regeneration and hypertrophy, which is accompanied by intensive incorporation of 14C-leucin into glandular proteins. Sodium thiosulfate prevents the development of stromal edema and intracellular edema of the acinar cells and retards the development of acinar cell hypertrophy. The drug produces an inhibitory action on 14C-leucin incorporation into pancreatic proteins.     

Glutamate dehydrogenase activity in the pancreatic tissue in acute experimental pancreatitis and under the action of sodium thiosulphate

It has been established that the development of acute pancreatitis is accompanied by the reduced activity of glutamate dehydrogenase in the mitochondrial fraction of pancreas, pronounced in the focus of tissue necrosis and less expressed in the reactive inflammation focus. Besides this in the pancreas redistribution of enzyme, activity in the subcellular organelles takes place and enzyme activity emerges in the cytosol and further--in the blood and peritoneum liquid. Sodium thiosulfate has a marked correlation effect.     

硫对铅污染水稻土微生物活性及群落结构的影响

对含有不同浓度铅的水稻土添加硫代硫酸钠进行土培试验,研究硫作用下铅污染水稻土微生物活性及群落结构的变化.结果表明:添加硫底物后,土壤的氧化还原电位(Eh)升高,呼吸强度增强,硫氧化菌的数量显著增加.硫促进了土壤中硫氧化菌等微生物的生长并引起群落结构的变化,克隆测序表明,加硫处理下土壤微生物的特异性条带与拟杆菌、硫杆菌、β-变形菌和嗜酸菌具有很高的相似性.硫处理下土壤碳酸盐结合态及铁锰结合态铅含量发生了显著变化.     

A nuclear magnetic relaxation study of conformational changes induced by substrate and temperature in bovine liver thiosulfate sulfurtransferase and yeast hexokinase

Nuclear magnetic relaxation studies have been performed on thiosulfate sulfurtransferase (EC 2.8.1.1) and hexokinase (EC 2.7.1.1). Observation of proton spin-lattice relaxation times T1 indicates that structural transitions occur in these enzymes in the range 0-40 degrees C and that there are different temperature-dependent forms of thiosulfate sulfurtransferase and hexokinase. Thermal transitions between these forms are affected by the binding of the substrates. The results may be due to changes in the interactions between the structural domains into which the single polypeptide chains of thiosulfate sulfurtransferase and hexokinase are folded.     

Protein changes in Lepidium sativum L. exposed to Hg during soil phytoremediation

Some investigations have been carried out in this study to find the best technique of soil reclamation in mercurypolluted soil. In this study, we examined Lepidium sativum L. as a plant useful for Hg phytoextraction. The simultaneous application of compost and thiosulfate was explored as a possible method of enhancing the process of phytoextraction. The results of the investigations of plant protein changes during assisted Hg phytoextraction were also provided. The results of the study show that combined use of compost and thiosulfate significantly increased both the total Hg accumulation and its translocation to aerial plant tissues. Plant protein analysis showed that L. sativum L. has the ability to respond to environmental stress condition by the activation of additional proteins. The additional proteins, like homocysteine methyltransferase, ribulose bisphosphate carboxylases (long and short chains), 14-3-3-like protein, and biosynthesis-related 40S ribosomal protein S15, were activated in plant shoots only in experiments carried out in Hg-polluted soil. There were no protein changes observed in plants exposed to compost and thiosulfate. It suggests that the combined use of compost and thiosulfate decreased Hg toxicity.     

Cytological research on the action of sodium thiosulfate on the process of induced acute pancreatitis in rats

The influence of sodium thiosulfate (STS) on the process of experimental acute pancreatitis (EAP) in rats was studied by cytomorphology, morphometry, autoradiography and cytophotometry. The influence was shown to vary at different stages of disease development. At the first stage ("primary effect" state) STS leads to the increase in the stability of exocrine pancreacytes (EP) against the toxins and to the decrease in the activity of proteases formed during necrobiosis. This results in the drop of the number of degrading EP and of the degree of inter- and intracellular oedema, and brings about shifts towards the normal values of the nucleus cytoplasm shapes, the nucleus/cytoplasm ratio, the EP population structure and their RNA and protein content. At the second stage STS stimulates DNA synthesis in EP and their proliferation leading to accelerated restoration of the number of viable cells. STS also stimulates the regeneration process hence preventing pancreatitis from passage to its chronic form. The mechanism of STS action of EP functions in normal cells and during pathogenesis is discussed.     

Electrochemistry and spectroscopy of sulfate and thiosulfate complexes of iron porphyrins

The electrochemical and spectroscopic properties of the complex formed by the addition of thiosulfate to ferric porphyrins were examined. The NMR spectrum of the thiosulfate-ferric porphyrin complex was consistent with a high-spin ferric complex, while the EPR spectrum at liquid nitrogen temperatures indicated that the complex under these conditions was low-spin. Such behavior has been previously observed for other ferric porphyrin complexes. The visible spectra were characterized by a shift in the Soret band to higher energies, with smaller changes in the longer wavelength region. The complex was reasonably stable in DMF, but slowly reduced over several hours to Fe^II(TPP) and S₄O₆ ²⁻. The voltammetric behavior of the thiosulfate complex in DMF consists of two waves, the first of which was irreversible. The ferric/ferrous reduction in the presence of thiosulfate was shifted negatively about 400 mV, compared to the Fe(TPP)(Cl) reduction. The visible, NMR and EPR spectra were most consistent with a Fe-S bonded ferric porphyrin-thiosulfate complex, Fe(P)(SSO₃)⁻. The kinetics of the reduction of ferric porphyrin by thiosulfate in DMSO indicated an autocatalytic mechanism, where the first step is the formation of the catalyst. The identity of the catalyst could not be determined because it must be present at low concentrations, but it is formed from the reaction of the ferric complex with thiosulfate. Coordination of thiosulfate to the porphyrin was not necessary for the reduction to occur, and the reduction of Fe(TPP)(Cl) by thiosulfate was accelerated by the addition of sulfate. Under these conditions, sulfate had replaced thiosulfate as the axial ligand for the ferric porphyrin. In the presence of sulfate, the reduction occurred in a single kinetic pseudo-first order step.     

Thiosulfate metabolism in Rhodopseudomonas palustris

The cells of the purple nonsulfur bacterium Rhodopseudomonas palustris, Nakamura strain, are capable of oxidizing thiosulfate and sulfide both under the anaerobic conditions in the light and under the aerobic conditions in the dark. Regardless of the presence of thiosulfate in the medium, the cells contain thiosulfate reductase, rodanase, thiosulfate oxidase, and sulfite oxidase. However, the capability to oxidize thiosulfate and sulfide is induced in Rh. palustris after the cells have been incubated in the presence of thiosulfate for 2--4 hours. The process of induction is related to the synthesis of protein components. Decomposition of thiosulfate in Rh. palustris when its concentration in the medium is low (2--5 mM) is accompanied with the formation of an equimolar quantity of sulfate. When the concentration of thiosulfate is higher (10--20 mM), the products of its oxidation are tetrathionate and sulfate. Therefore, the metabolic pathway of thiosulfate in Rh. palustris depends on its concentration in the medium.     

Chemolithoautotrophic growth on elemental sulfur (S°) and respiratory oxidation of S° by Thiobacillus versutus and another sulfur-oxidizing bacterium

Abstract Thiobacillus versutus was shown to grow chemolithoautotrophically under microaerophilic conditions, with crystalline elemental sulfur (S°) and thiosulfate as sole electron source. The exponential growth rate on S° ( μ = 0.106 h⁻¹) measured in batch culture was similar to the reported maximum growth rate on thiosulfate in chemostat cultures. The rates of thiosulfate, S° and sulfite oxidation were measured respirometrically using an oxygen electrode. During growth under air on thiosulfate, as well as under low oxygen pressure on S° and thiosulfate, a relatively strong sulfuroxidizing activity (SOA) was measured. The induction of the SOA on cells growing with thiosulfate and the similar growth rates on S° and thiosulfate strongly suggest that S° could be an important intermediate during thiosulfate utilization.     

Growth of thermophilic obligately autotrophic hydrogen-oxidizing bacteria on thiosulfate

Thermophilic obligately autotrophic H₂-oxidizing bacteria from Icelandic hot springs were tested for growth on thiosulfate. Ten strains were tested and all grew on thiosulfate but not on sulfite or sulfur. The product of thiosulfate oxidation was sulfate. The growth rate on thiosulfate was slower (μ=0.12 h^-1) than on H₂ (μ=0.34 h^-1). Washed cells which had been grown on thiosulfate could oxidize thiosulfate rapidly but H₂-grown cells oxidized thiosulfate much more slowly and with about a 3 h lag time. The bacteria would not grow on agar medium under H₂ but grew on agar medium containing thiosulfate.     

Are thiosulfate and trithionate intermediates in dissimilatory sulfate reduction?

The fate of 35-S during anaerobic metabolism of [35-S]sulfate, [35-S]thiosulfate, and [35-S]sulfate plus unlabeled thiosulfate by washed cell suspensions of Desulfovibrio spp, and of [35-S]thiosulfate by growing D. desulfuricans was examined. The results appear to be inconsistent with the hypothesis that thiosulfate is an intermediate in sulfate reduction. Since thiosulfate was produced from trithionate, the latter is also unlikely to be an intermediate in the reduction pathway. Extracts of D. desulfuricans catalysed exchange between sulfite and the sulfonate group of thiosulfate.     

Effect of Thiosulfate on the Photosynthetic Growth of Rhodopseudomonas palustris

Cell yields of Rhodopseudomonas palustris grown photoheterotrophically in pyruvate-mineral salts medium were increased by the photooxidation of added thiosulfate. However, thiosulfate had no effect on cell yields of cultures grown aerobically in darkness, although thiosulfate was also oxidized. The presence of thiosulfate increased photosynthetic cell yields on a variety of other organic substrates. Growth of cells in thiosulfate-containing medium, or the addition of thiosulfate to cells grown in thiosulfate-free medium, induced the formation of a thiosulfate-oxidizing system which quantitatively photooxidized thiosulfate to sulfate. R. palustris grew photoautotrophically with thiosulfate as an oxidizable substrate. Large amounts of supplemental bicarbonate carbon were incorporated when cells were grown photosynthetically in pyruvate-thiosulfate medium. Cells harvested after photoautotrophic or photoheterotrophic growth in fumarate-thiosulfate medium fixed (14)CO(2) at an 8- to 10-fold greater rate when provided with thiosulfate. The evolution of (14)CO(2) from pyruvate-1-(14)C during photoassimilation by R. palustris was greatly suppressed by the presence of thiosulfate. The increase in photoheterotrophic cell yields of R. palustris caused by the oxidation of thiosulfate may result from assimilation of substrate carbon which is normally evolved as carbon dioxide.     

Thiosulfate sulfur transferases (Rhodaneses) ofChlorobium vibrioforme f.thiosulfatophilum

Two enzymes containing thiosulfate sulfur transferase activity were purified fromChlorobium vibrioforme f.thiosulfatophilum by ion exchange chromatography, gel filtration and isoelectrofocusing. Enzyme I is a basic protein with an isoelectric point at pH 9.2 and has a molecular weight of 39,000. TheK _m-values for thiosulfate and cyanide of the purified basic protein were 0.25 mM (thiosulfate) and 5 mM (cyanide). Enzyme II is an acidic protein. The enzyme has an isoelectric point at pH 4.6–4.7 and a molecular weight of 34,000. TheK _m-values of the acidic protein were found to be 5 mM for thiosulfate and 125 mM for cyanide.In addition to thiosulfate sulfur transferase activity, cellfree extracts ofChlorobium vibrioforme f.thiosulfatophilum also contained low thiosulfate oxidase activity and negligible thiosulfate reductase activity. The percent distribution of thiosulfate sulfur transferase and thiosulfate oxidase activities in the organism was independent of the offered sulfur compound (thiosulfate, sulfide or both) in the medium.Abbreviations C Chlorobium - SDS sodium dodecylsulfate Dedicated to Prof. Dr. Norbert Pfennig on the occasion of his 60th birthday     

Assimilatory sulfur metabolism in marine microorganisms: a novel sulfate transport system in Alteromonas luteo-violaceus.

The sulfate transport mechanism of a marine bacterium, Alteromonas luteo-violaceus, was unique among microorganisms in its extremely low affinity for the sulfate analog thiosulfate. Distinguishing characteristics included weak inhibition of sulfate transport by thiosulfate, inability to transport thiosulfate effectively, poor growth using thiosulfate as the sole source of sulfur, and a mild effect of the sulfhydryl reagent para-hydroxymercuribenzoate. In contrast, sulfate transport by a marine pseudomonad, Pseudomonas halodurans, was strongly inhibited by thiosulfate, and para-hydroxymercuribenzoate reversibly but completely blocked sulfate transport.     

Sulfite-oxido-reductase is involved in the oxidation of sulfite in Desulfocapsa sulfoexigens during disproportionation of thiosulfate and elemental sulfur

The enzymatic pathways of elemental sulfur and thiosulfate disproportionation were investigated using cell-free extract of Desulfocapsa sulfoexigens. Sulfite was observed to be an intermediate in the metabolism of both compounds. Two distinct pathways for the oxidation of sulfite have been identified. One pathway involves APS reductase and ATP sulfurylase and can be described as the reversion of the initial steps of the dissimilatory sulfate reduction pathway. The second pathway is the direct oxidation of sulfite to sulfate by sulfite oxidoreductase. This enzyme has not been reported from sulfate reducers before. Thiosulfate reductase, which cleaves thiosulfate into sulfite and sulfide, was only present in cell-free extract from thiosulfate disproportionating cultures. We propose that this enzyme catalyzes the first step in thiosulfate disproportionation. The initial step in sulfur disproportionation was not identified. Dissimilatory sulfite reductase was present in sulfur and thiosulfate disproportionating cultures. The metabolic function of this enzyme in relation to elemental sulfur or thiosulfate disproportionation was not identified. The presence of the uncouplers HQNO and CCCP in growing cultures had negative effects on both thiosulfate and sulfur disproportionation. CCCP totally inhibited sulfur disproportionation and reduced thiosulfate disproportionation by 80% compared to an unamended control. HQNO reduced thiosulfate disproportionation by 80% and sulfur disproportionation by 90%.     

Thiosulfate oxidation and mixotrophic growth of Methylobacterium oryzae

Thiosulfate oxidation and mixotrophic growth with succinate or methanol plus thiosulfate was examined in nutrient-limited mixotrophic condition for Methylobacterium oryzae CBMB20, which was recently characterized and reported as a novel species isolated from rice. Methylobacterium oryzae was able to utilize thiosulfate in the presence of sulfate. Thiosulfate oxidation increased the protein yield by 25% in mixotrophic medium containing 18.5 mmol.L-1 of sodium succinate and 20 mmol.L-1 of sodium thiosulfate on day 5. The respirometric study revealed that thiosulfate was the most preferable reduced inorganic sulfur source, followed by sulfur and sulfite. Thiosulfate was predominantly oxidized to sulfate and intermediate products of thiosulfate oxidation, such as tetrathionate, trithionate, polythionate, and sulfur, were not detected in spent medium. It indicated that bacterium use the non-S4 intermediate sulfur oxidation pathway for thiosulfate oxidation. Thiosulfate oxidation enzymes, such as rhodanese and sulfite oxidase activities appeared to be constitutively expressed, but activity increased during growth on thiosulfate. No thiosulfate oxidase (tetrathionate synthase) activity was detected.     

A sulfate,sulfite and thiosulfate incorporating system inCandida utilis

Sulfate, sulfite and thiosulfate incorporation in the yeastCandida utilis is inhibited by extracellular sulfate, sulfite and thiosulfate and by sulfate analogues selenate, chromate and molybdate. The three processes are blocked if sulfate, sulfite, thiosulfate, cysteine and homocysteine are allowed to accumulate endogenously. Incorporation of the three inorganic sulfur oxy anions is inactivated by heat at the same rate. Mutants previously shown to be defective in sulfate incorporation are also affected in sulfite and thiosulfate uptake. Revertants of these mutants selected by plating in ethionine-supplemented minimal medium recovered the capacity to incorporate sulfate, sulfite and thiosulfate. These results taken together with previous evidence demonstrate the existence of a common sulfate, sulfite and thiosulfate incorporating system in this yeast.     

Thiosulfate oxidation by nonsulfur purple bacteria

The capability to oxidize thiosulfate was studied in 11 cultures of purple bacteria belonging to Rhodomicrobium vannielii, Rhodopseudmonas viridis, Rh. sphaeroides, Rh. capsulata, and Rhodospirillum rubrum. All the bacteria oxidized thiosulfate under aerobic conditions in the dark. The strains 2R, 8259, A1, A2 and D1 of Rh. sphaeroides oxidized thiosulfate under anaerobic conditions in the light, and the process was coupled with carbon dioxide fixation. All the strains contained thiosulfate reductase, and the majority of them possessed also the activity of thiosulfate oxidase and sulfite oxidase.     

Growth of thermophilic, obligatorily chemolithoautotrophic hydrogen-oxidizing bacteria related to Hydrogenobacter with thiosulfate and elemental sulfur as electron and energy source

Abstract Strains related to Hydrogenobacter , a genus of thermophilic, obligatorily chemolithoautotrophic bacteria, were able to utilize elemental sulfur or thiosulfate, as well as molecular hydrogen, as sole electron and energy source. Extracellular elemental sulfur was produced as an intermediate during oxidation of thiosulfate. Growth with thiosulfate alone was strongly microaerophilic, whereas no hydrogenase activity was detected. Mixolithotrophic growth with both hydrogen and thiosulfate was faster than with hydrogen alone, and the cells harbored a hydrogenase activity comparable to that of cells grown under hydrogen without thiosulfate.     

Metabolism of thiosulfate and tetrathionate by heterotrophic bacteria from soil

Two heterotrophic bacteria that oxidized thiosulfate to tetrathionate were isolated from soil. The enzyme system in one of the isolates (C-3) was constitutive, but in the other isolate (A-50) it was induced by thiosulfate or tetrathionate. The apparent K(m) for oxygen for thiosulfate oxidation by A-50 was about 223 mum, but, for lactate oxidation by A-50 or thiosulfate oxidation by C-3, the apparent K(m) for oxygen was below 2 mm. The oxidation of thiosulfate by A-50 was first order with respect to oxygen from 230 mum. The rate of oxidation was greatest at pH 6.3 to 6.8 and at about 10 mm thiosulfate, and it was strongly inhibited by several metal-binding reagents. Extracts of induced A-50 reduced ferricyanide, endogenous cytochrome c, and mammalian cytochrome c in the presence of thiosulfate. A-50, once induced to oxidize thiosulfate, also reduced tetrathionate to thiosulfate in the presence of an electron donor such as lactate. The optimal pH for this reaction was at 8.5 to 9.5, and the reaction was first order with respect to tetrathionate. There was no correlation between the formation of the thiosulfate-oxidizing enzyme of A-50 and the incorporation of thiosulfate-sulfur into cell sulfur. Thiosulfate did not affect the growth rate or yield of A-50.