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Determination of sulfide in brain tissue by gas dialysis/ion chromatography: postmortem studies and two case reports.

An analytical method for the determination of sulfide in human and rat brain is described. It utilizes a continuous flow gas dialysis pretreatment and quantitation by ion chromatography with electrochemical detection. Rat brain sulfide levels were reliably measured after fatal intoxication by intraperitoneal injection of NaHS. By expeditious analysis of samples it was possible to demonstrate the presence of endogenous levels of sulfide in both rat and human brain as well as to measure elevated brain levels of sulfide after intoxication. In postmortem rat brain tissue, elevated sulfide levels could still be reliably demonstrated 96 h after death if the bodies had been refrigerated at 4 degrees C. Two case studies of human hydrogen sulfide inhalation fatalities are presented. The described method was able to measure significantly elevated sulfide levels in both cases.

Adult↗
PubMed2003

The effect of 5-aminosalicylic acid-containing drugs on sulfide production by sulfate-reducing and amino acid-fermenting bacteria.

The toxic, bacterial metabolite sulfide is implicated in ulcerative colitis. Ulcerative colitis patients taking 5-aminosalicylic acid-containing drugs have lower fecal sulfide levels than those not taking these drugs. The effects of sulfasalazine, balsalazide, olsalazine, and 5-aminosalicylic acid on sulfide production were studied in a three-stage chemostat pulsed on days 1 to 3 with 5 g sulfasalazine (40 mM) and in pure cultures of amino acid-fermenting and sulfate-reducing bacteria. By the third day of sulfasalazine addition to the chemostat, sulfide concentrations in vessels 1 through 3 had dropped from 1.73, 1.78, and 1.43 mM to 0.01, 0.15, and 0.9 mM, respectively. In pure cultures, 50% inhibition of sulfide production from amino acids occurred at 2.5 +/- 0.05 mM for sulfasalazine, 5 +/- 0.2 mM for olsalazine, 6 +/- 1 mM for balsalazide, and more than 20 mM for 5-aminosalicylic acid. Fifty percent inhibition of sulfide production from sulfate occurred at 0.25 +/- 0.05 mM for sulfasalazine, 0.7 +/- 0.2 mM for balsalazide, and 9.0 +/- 1.0 mM for 5-aminosalicylic acid. The order of effectiveness of equimolar concentrations of drugs (most effective first) in this assay was sulfasalazine, then olsalazine (though given clinically at half the dose of other 5-aminosalicylic acid prodrugs) and balsalazide, and lastly 5-aminosalicylic acid. Inhibition of sulfide production by 5-aminosalicylic acid-containing drugs may contribute to their therapeutic effect in ulcerative colitis.

Amino Acids↗
PubMed2006

Anaerobic sulfide oxidation with nitrate by a freshwater Beggiatoa enrichment culture.

A lithotrophic freshwater Beggiatoa strain was enriched in O2-H2S gradient tubes to investigate its ability to oxidize sulfide with NO3- as an alternative electron acceptor. The gradient tubes contained different NO3- concentrations, and the chemotactic response of the Beggiatoa mats was observed. The effects of the Beggiatoa sp. on vertical gradients of O2, H2S, pH, and NO3- were determined with microsensors. The more NO3- that was added to the agar, the deeper the Beggiatoa filaments glided into anoxic agar layers, suggesting that the Beggiatoa sp. used NO3- to oxidize sulfide at depths below the depth that O2 penetrated. In the presence of NO3- Beggiatoa formed thick mats (>8 mm), compared to the thin mats (ca. 0.4 mm) that were formed when no NO3- was added. These thick mats spatially separated O2 and sulfide but not NO3- and sulfide, and therefore NO3- must have served as the electron acceptor for sulfide oxidation. This interpretation is consistent with a fourfold-lower O2 flux and a twofold-higher sulfide flux into the NO3- -exposed mats compared to the fluxes for controls without NO3-. Additionally, a pronounced pH maximum was observed within the Beggiatoa mat; such a pH maximum is known to occur when sulfide is oxidized to S0 with NO3- as the electron acceptor.

Anaerobiosis↗
PubMed2000

Influence of sulfide and temperature on species composition and community structure of hot spring microbial mats.

In solfataric fields in southwestern Iceland, neutral and sulfide-rich hot springs are characterized by thick bacterial mats at 60 to 80 degrees C that are white or yellow from precipitated sulfur (sulfur mats). In low-sulfide hot springs in the same area, grey or pink streamers are formed at 80 to 90 degrees C, and a Chloroflexus mat is formed at 65 to 70 degrees C. We have studied the microbial diversity of one sulfur mat (high-sulfide) hot spring and one Chloroflexus mat (low-sulfide) hot spring by cloning and sequencing of small-subunit rRNA genes obtained by PCR amplification from mat DNA. Using 98% sequence identity as a cutoff value, a total of 14 bacterial operational taxonomic units (OTUs) and 5 archaeal OTUs were detected in the sulfur mat; 18 bacterial OTUs were detected in the Chloroflexus mat. Although representatives of novel divisions were found, the majority of the sequences were >95% related to currently known sequences. The molecular diversity analysis showed that Chloroflexus was the dominant mat organism in the low-sulfide spring (1 mg liter(-1)) below 70 degrees C, whereas Aquificales were dominant in the high-sulfide spring (12 mg liter(-1)) at the same temperature. Comparison of the present data to published data indicated that there is a relationship between mat type and composition of Aquificales on the one hand and temperature and sulfide concentration on the other hand.

Archaea↗
PubMed2004

Dissimilatory arsenate reduction with sulfide as electron donor: experiments with mono lake water and Isolation of strain MLMS-1, a chemoautotrophic arsenate respirer.

Anoxic bottom water from Mono Lake, California, can biologically reduce added arsenate without any addition of electron donors. Of the possible in situ inorganic electron donors present, only sulfide was sufficiently abundant to drive this reaction. We tested the ability of sulfide to serve as an electron donor for arsenate reduction in experiments with lake water. Reduction of arsenate to arsenite occurred simultaneously with the removal of sulfide. No loss of sulfide occurred in controls without arsenate or in sterilized samples containing both arsenate and sulfide. The rate of arsenate reduction in lake water was dependent on the amount of available arsenate. We enriched for a bacterium that could achieve growth with sulfide and arsenate in a defined, mineral medium and purified it by serial dilution. The isolate, strain MLMS-1, is a gram-negative, motile curved rod that grows by oxidizing sulfide to sulfate while reducing arsenate to arsenite. Chemoautotrophy was confirmed by the incorporation of H(14)CO(3)(-) into dark-incubated cells, but preliminary gene probing tests with primers for ribulose-1,5-biphosphate carboxylase/oxygenase did not yield PCR-amplified products. Alignment of 16S rRNA sequences indicated that strain MLMS-1 was in the delta-Proteobacteria, located near sulfate reducers like Desulfobulbus sp. (88 to 90% similarity) but more closely related (97%) to unidentified sequences amplified previously from Mono Lake. However, strain MLMS-1 does not grow with sulfate as its electron acceptor.

Arsenates↗
PubMed1993

Sulfide toxicity: mechanical ventilation and hypotension determine survival rate and brain necrosis.

Occupational exposure to hydrogen sulfide is one of the leading causes of sudden death in the workplace, especially in the oil and gas industry. High-dose exposure causes immediate neurogenic apnea and death; lower doses cause "knockdown" (transient loss of consciousness, with apnea). Because permanent neurological sequelae have been reported, we sought to determine whether sulfide can directly kill central nervous system neurons. Ventilated and unventilated rats were studied to allow administration of higher doses of sulfide and to facilitate physiological monitoring. It was extremely difficult to produce cerebral necrosis with sulfide. Only one of eight surviving unventilated rats given high-dose sulfide (a dose that was lethal in > or = 50% of animals) showed cerebral necrosis. Mechanical ventilation shifted the dose that was lethal in 50% of the animals to 190 mg/kg from 94 mg/kg in the unventilated rats. Sulfide was found to potently depress blood pressure. Cerebral necrosis was absent in the ventilated rats (n = 11), except in one rat that showed profound and sustained hypotension to < or = 35 Torr. Electroencephalogram activity ceased during exposure but recovered when the animals regained consciousness. We conclude that very-high-dose sulfide is incapable of producing cerebral necrosis by a direct histotoxic effect.

Animals↗
PubMed2006

Detoxifying toxicants: interactions between sulfide and iron toxicity in freshwater wetlands.

In many Dutch freshwater wetlands, concentrations of sulfate in the surface water and groundwater have increased. It is especially in peaty areas that this can lead to problems, including the reduction of sulfate to toxic sulfide. Our aquarium experiments showed that even low sulfide concentrations of 50 micromol/L are toxic to the freshwater macrophyte Nitella flexilis and the freshwater oligochaete Ophidonais serpentina. Sulfide toxicity can be modified by the availability of free iron in soil moisture or sediment from iron-rich groundwater discharge. The iron precipitates the sulfide, thereby immobilizing it and decreasing its toxicity. However, iron itself can be a toxicant as well. We found a detoxifying effect of moderate iron concentrations on sulfide toxicity, as well as a toxic effect of high iron concentrations on the growth of Potamogeton acutifolius. At the intermediate range, the formation of metal sulfides can simultaneously decrease metal and sulfide toxicity. Results of the experiments are discussed in relation to hydrological changes in freshwater wetlands.

Fresh Water↗
PubMed2006

Online oxygen control for sulfide oxidation in anaerobic treatment of high-sulfate wastewater.

A new technique for sulfide control was investigated in an upflow-anaerobic filter (UAF) treating high-strength, sulfate-rich wastewater. The technique used periodic oxygen injection using oxidation-reduction potential (ORP) as a controlling parameter to regulate oxygen injection. The UAF was operated at a constant influent total-organic carbon of 6740 mg/L but with different influent sulfates of 1000, 3000, and 6000 mg/L. At 1000 and 3000 mg/L influent sulfates, the produced sulfide did not impose any inhibition to methane-producing bacteria (MPB). However, at 6000 mg/L influent sulfate, the produced dissolved sulfide of 804 mg S/L (free sulfide = 280 mg S/L) severely inhibited the methanogenesis, but not the sulfidogenesis. Upon oxygen injection at elevated ORP of -265 mV, sulfides were almost completely eliminated with a concomitant improvement in methane yield by 46%. If oxygenation was excessive because of an oversetting of ORP, the excess oxygen could be used rapidly by facultative heterotrophs, thereby protecting the MPB from oxygen stress. Regarding online sulfide oxidation, it was found that the biogas and injected oxygen needed to pass through an aqueous layer containing trace metals, which were found to have a significant catalytic effect on abiotic sulfide oxidation.

Anaerobiosis↗
PubMed2002

Synthesis and characterization of metal sulfide clusters for toxicological studies.

Zinc sulfide clusters were synthesized and characterized at low micromolar concentrations to assess the effect of metal-sulfide ligands on metal toxicity to aquatic organisms in oxic environments. Recommended preparation times are greater than 2 h initial reaction of equimolar sodium sulfide and zinc nitrate, followed by oxic aeration for 3 d. Ionic strength, pH, and anoxic stabilization time were found to be relatively unimportant in controlling the final yield. Adsorptive losses of zinc sulfide (ZnS) clusters to surfaces, however, were significant for a variety of vessel materials and membrane filters. Ionic strength and pH were found to be important factors controlling the extent of adsorptive losses with minimal loss for pHs greater than 9 and for soft waters. The Ag(I), Cu(II), and Hg(II) as metal sulfides completely suppress the analysis of sulfide, whereas Pb(II), Mn(II), and Co(II) partially suppress the analysis of sulfide by the methylene blue technique. Ultraviolet and fluorescence spectra are shown for synthesized ZnS clusters.

Adsorption↗
PubMed2002

[Study of radiation synovectomy using (188)Re-Sulfide in hemophilic arthritis].

OBJECTIVE: To study the effectiveness of radiation synovectomy with (188)Re-sulfide. METHODS: Twenty rabbit models of joint synovitis were injected intra-articularly with different doses of (188)Re-sulfide from 7.4 to 37.0 MBq. By pathological examination, the effects of (188)Re-sulfide on synovium and cartilage were evaluated. Clinically, 10 joints of 7 cases of hemophilic arthritis with (188)Re-sulfide radiation synovectomy were performed. MRI was taken before and after the synovectomy to evaluate the treatment effects. RESULTS: In rabbit models, when (188)Re-sulfide dose larger than 14.8 MBq, the radiation effect on synovitis was remarkable, including thinning the thickened synovium and reducing the inflammatory cells. When radio-activity dose increased to 37.0 MBq, pathological damage was noted in cartilage. Clinical trial demonstrated that radiation synovectomy by (188)Re-sulfide could reduce the frequencies of intra-articular hemorrhage. MRI showed that edema and villi reduced. CONCLUSIONS: Radiation synovectomy using (188)Re-sulfide is effective on synovitis in hemophilic arthritis.

Animals↗
PubMed2003

Use of ORP (oxidation-reduction potential) to control oxygen dosing for online sulfide oxidation in anaerobic treatment of high sulfate wastewater.

In this study, oxidation-reduction potential (ORP) was used as a controlling parameter to regulate oxygen dosing to the recycled biogas for online sulfide oxidation in an upflow anaerobic filter (UAF) system. The UAF was operated with a constant influent COD of 18,000 mg/L, but with different influent sulfates of 1000, 3000 and 6000 mg/L. The reactor was initially operated under a natural ORP of -290 mV (without oxygen injection), and was then followed by oxygenation to raise its ORP by 25 mV above the natural level for each influent sulfate condition. At 6,000 mg/L sulfate without oxygen injection, the dissolved sulfide reached 733.8 mg S/L with a corresponding free sulfide of 250.3 mg S/L, thus showing a considerable inhibition to methanogens. Upon oxygenation to raise its ORP to -265 mV (i.e., a 25 mV increase), the dissolved sulfide was reduced by more than 98.5% with a concomitant 45.9% increase of the methane yield. Under lower influent sulfate levels of 1,000 and 3,000 mg/L, the levels of sulfides produced, even under the natural ORP, did not impose any noticeable toxicity to methanogens. Upon oxygenation to raise the ORP by +25 mV, the corresponding methane yields were actually reduced by 15.5% and 6.2%, respectively. However, such reductions were not due to the adverse impact of the elevated ORP; instead, they were due to a diversion of some organic carbon to support the facultative activities inside the reactor as a result of excessive oxygenation. In other words, to achieve satisfactory sulfide oxidation for the lower influent sulfate conditions, it was not necessary to raise the ORP by as much as +25 mV. The ORP increase actually needed depended on both the influent sulfate and also actual wastewater characteristics. This study had proved that the ORP controlled oxygenation was reliable for achieving consistent online sulfide control.

Automation↗
PubMed2003

[Changes of telomerase activity and hTERT mRNA expression in the process of apoptosis of HL-60 cells induced by arsenic sulfide].

AIM: To explore the effect of arsenic sulfide on telomerase activity of HL-60 cells. METHODS: Telomerase activity was determined by PCR-ELISA. The expression of hTERT-mRNA was analyzed by semi-quantitative RT-PCR. Flow cytometry was used to analyze the cell cycle,apoptosis and CD11b expression of HL-60 cells. RESULTS: Treament of HL-60 cells with 0.3-0.6 mg/L arsenic sulfide for 72 h did not induce apoptosis of the cells, while 1.5-3.0 mg/L did. Furthermore, 1.5-3.0 mg/L arsenic sulfide inhibited the telomerase activity and hTERT-mRNA expression in HL-60 cells. Proportion of the cells in G2/M phase was increased when being treated with arsenic sulfide. 3.0 mg/L arsenic sulfide upregulated CD11b expression in HL-60 cells from 1.0 % to 6.8%. CONCLUSION: Arsenic sulfide can inhibit telomerase activity. The increase of proportion of HL-60 cells in G2/M phase may be related to the reduction of telomerase activity. High dosage of arsenic sulfide can slightly induce differentiation of HL-60 cells.

Apoptosis↗
PubMed2004

Comparison of field olfactometers in a controlled chamber using hydrogen sulfide as the test odorant.

A standard method for measuring and quantifying odour in the ambient air utilizes a portable odour detecting and measuring device known as a field olfactometer (US Public Health Service Project Grant A-58-541). The field olfactometer dynamically dilutes the ambient air with carbon-filtered air in distinct ratios known as "Dilutions-to-Threshold" dilution factors (D/Ts), i.e. 2, 4, 7, 15, etc. Thirteen US states and several cities in North America currently utilize field olfactometry as a key component of determining compliance to odour regulations and ordinances. A controlled environmental chamber was utilized, with hydrogen sulfide as the known test odorant. A hydrogen sulfide environment was created in this controlled chamber using an Advanced Calibration Designs, Inc. Cal2000 Hydrogen Sulfide Generator. The hydrogen sulfide concentration inside the chamber was monitored using an Arizona Instruments, Inc. Jerome Model 631 H2S Analyzer. When the environmental chamber reached a desired test concentration, test operators entered the chamber. The dilution-to-threshold odour concentration was measured using a Nasal Ranger Field Olfactometer (St Croix Sensory, Inc.) and a Barnebey Sutcliffe Corp. Scentometer. The actual hydrogen sulfide concentration was also measured at the location in the room where the operators were standing while using the two types of field olfactometers. This paper presents a correlation between dilution-to-threshold values (D/T) and hydrogen sulfide ambient concentration. For example, a D/T of 7 corresponds to ambient H2S concentrations of 5.7-15.6 microg/m3 (4-11 ppbv). During this study, no significant difference was found between results obtained using the Scentometer or the Nasal Ranger (r = 0.82). Also, no significant difference was found between results of multiple Nasal Ranger users (p = 0.309). The field olfactometers yielded hydrogen sulfide thresholds of 0.7-3.0 microg/m3 (0.5-2.0 ppbv). Laboratory olfactometry yielded comparable thresholds of 0.64-1.3 microg/m3 (0.45-0.9 ppbv). These thresholds are consistent with published values.

Air Pollutants↗
PubMed2004

Hydrogen sulfide emission in sewer networks: a two-phase modeling approach to the sulfur cycle.

Wherever transport of anaerobic wastewater occurs, potential problems associated with hydrogen sulfide in relation to odor nuisance, health risk and corrosion exist. Improved understanding of prediction of hydrogen sulfide emission into the sewer atmosphere is needed for better evaluation of such problems in sewer networks. A two-phase model for emission of hydrogen sulfide along stretches of gravity sewers is presented to estimate the occurrence of both sulfide in the water phase and hydrogen sulfide in the sewer atmosphere. The model takes into account air-water mass transfer of hydrogen sulfide and interactions with other processes in the sulfur cycle. Various emission scenarios are simulated to illustrate the release characteristics of hydrogen sulfide.

Air Pollutants↗
PubMed2005

Simulation of sulfide buildup in wastewater and atmosphere of sewer networks.

A model concept for prediction of sulfide buildup in sewer networks is presented. The model concept is an extension to--and a further development of--the WATS model (Wastewater Aerobic-anaerobic Transformations in Sewers), which has been developed by Hvitved-Jacobsen and co-workers at Aalborg University. In addition to the sulfur cycle, the WATS model simulates changes in dissolved oxygen and carbon fractions of different biodegradability. The sulfur cycle was introduced via six processes: 1. sulfide production taking place in the biofilm covering the permanently wetted sewer walls; 2. biological sulfide oxidation in the permanently wetted biofilm; 3. chemical and biological sulfide oxidation in the water phase; 4. sulfide precipitation with metals present in the wastewater; 5. emission of hydrogen sulfide to the sewer atmosphere and 6. adsorption and oxidation of hydrogen sulfide on the moist sewer walls where concrete corrosion may take place.

Biofilms↗
PubMed2006

[Survey of plasma lipid value in children in Beijing area and the changes of gaseous molecule-hydrogen sulfide in the ones with dyslipidemia].

OBJECTIVE: To evaluate plasma lipid value in children in Beijing areas and to explore the relationship between plasma hydrogen sulfide (H(2)S) level and lipid components. METHODS: A total of 971 healthy school students were chosen randomly, all coming from Beijing city and its counties. They were divided into four groups according to their gender and age (boys and girls in school age and in puberty). Body mass index (BMI) was calculated according to the measurement of body height and weight. Familial history, past medical history and the history of present illness were investigated. Physical examination was also carried on. Alanine aminotransferase (ALT), total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C) were detected by HITACHI 7060 automatic biochemical analyzer. Forty children (31 males and 9 females) with dyslipidemia were chosen randomly among them as patients. Other 60 children (38 males and 22 females) with normal plasma lipid level served as controls. Plasma H(2)S level was detected by modified sulfide electrode. RESULTS: There were 91 children with dyslipidemia (58 males and 33 females) in 971 students. The prevalence rate was 9.37%. The average value of BMI in patients was higher than that of controls. An association of increased ALT level with the prevalence of dyslipidemia was observed. Hydrogen sulfide concentration in plasma showed out skew distribution. Measurement data were presented as median (P(25), P(75)). Hydrogen sulfide was 34.40 (32.98, 35.47) micromol/L in children with dyslipidemia and 38.81(36.53, 40.66) micromol/L in controls. There was statistical difference between the two groups (P<0.01). Average value of plasma hydrogen sulfide was 35.54 (33.41, 39.24) micromol/L in males and 37.82 (33.84, 39.80) micromol/L in females. There was no difference in plasma hydrogen sulfide between male and female subjects (P>0.05). CONCLUSION: The prevalence rate of dyslipidemia in Beijing children is relatively high as compared with what it was during the past several decades. There was a significant decrease in plasma endogenous H(2)S level in children with dyslipidemia as compared with that of healthy children. There was an obvious correlation between plasma hydrogen sulfide and plasma lipids.

Adolescent↗
PubMed1989

Alkylaryl sulfides as peroxidase reducing substrates for prostaglandin H synthase. Probes for the reactivity and environment of the ferryl-oxo complex.

The peroxidase activity of prostaglandin (PGH) synthase catalyzes the reduction of PGG2 and other natural and synthetic hydroperoxides by reducing substrates. Sulfides serve as reductants by incorporating the oxo ligand from the ferryl-oxo complex which represents the higher oxidation state of the peroxidase (Compound I). A series of alkylaryl sulfides and substituted dihydrobenzo[b]thiophenes were synthesized to determine the electronic and steric requirements of PGH synthase for sulfide reducing substrates. Kinetic parameters were determined for most of the molecules by determining their ability to support reduction of 5-phenyl-4-pentenyl-1-hydroperoxide in the presence of PGH synthase purified from ram seminal vesicle microsomes. Electron-donating groups on the aryl moiety para to the sulfide enhanced reducing substrate activity (p = -0.8). As expected from previous results, the major oxidation product of p-methylthioanisole was the corresponding sulfoxide. The presence of a para-amino group increased binding to the enzyme and changed the reduction mechanism from oxygen transfer to electron transfer. The major oxidation product of p-(dimethylamino)thioanisole was identified as p-(methylamino)thioanisole; an equivalent amount of formaldehyde was produced. Increasing the size of the alkyl group attached to sulfur decreased the ability of the sulfide to act as a peroxidase reductant. The maximal turnover for reduction by p-methoxyphenylalkyl sulfides decreased 10-fold on substitution of isopropyl for ethyl. Chiral derivatives of benzo[b]thiophenes demonstrated differences in the ability of the two enantiomers to support reduction. Introduction of a carboxylic acid moiety anywhere in the molecule decreased the maximal turnover for reduction. Esterification of the carboxylate doubled the extent of reduction relative to the free acid. The results are used to develop models for the interaction of sulfides with Compound I of PGH synthase.

Allosteric Regulation↗
PubMed1986

Sulfide and sulfoxide derivatives of substituted benzimidazoles inhibit acid formation in isolated gastric glands by different mechanisms.

The sulfoxide and sulfide forms of three pairs of substituted benzimidazoles, including omeprazole, were investigated using isolated gastric glands and microsomal membranes containing H+,K+-adenosine Triphosphatase (ATPase). The sulfoxides inhibited stimulated aminopyrine (AP) uptake giving IC50 values between 0.47 and 1.1 microM, whereas the sulfides were less potent and showed a greater variation in IC50 values, 9.5 to 170 microM. The decrease in stimulated oxygen consumption induced by the sulfoxides was parallel to their inhibition of AP-uptake, with IC50 values of 0.40 to 3.7 microM, whereas the sulfides were virtually without effect, IC50 greater than 100 microM. The permeable buffers imidazole and 2,6-dimethylpyridine mimiced the effect of the sulfides on both AP accumulation and oxygen consumption. When tested on H+, K+-ATPase, an enzyme suggested to be the proton pump of the gastric mucosa, the sulfoxides inhibited the ATPase activity with IC50 values between 0.25 to 2.8 microM, in contrast to the sulfides, which were without inhibitory action. The sulfoxide-induced inhibition of AP-uptake in gastric glands and H+, K+-ATPase activity was prevented by the addition of beta-mercaptoethanol, whereas the mercaptane was without effect on sulfide-induced inhibition of AP-accumulation. When tested on vesicles containing H+, K+-ATPase, both the sulfide and sulfoxide derivatives dissipated the proton gradient generated by the enzyme, but only the sulfoxide-induced inhibition was prevented by the addition of beta-mercaptoethanol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗