Science.gov

Sample records for hydrogen sulfide h2s

  1. Hydrogen sulfide (H 2S) in urban ambient air

    NASA Astrophysics Data System (ADS)

    Kourtidis, K.; Kelesis, A.; Petrakakis, M.

    Despite indications of high hydrogen sulfide levels in some urban environments, only sparse measurements have been reported in the literature. Here we present one full year of hydrogen sulfide measurements in an urban traffic site in the city of Thessaloniki, Greece. In this 1-million-population city the H 2S concentrations were surprisingly high, with a mean annual concentration of 8 μg m -3 and wintertime mean monthly concentrations up to 20 μg m -3 (12.9 ppb). Daily mean concentrations in the winter were up to 30 μg m -3 (19.3 ppb), while hourly concentrations were up to 54 μg m -3 (34.8 ppb). During calm (wind velocity < 0.5 m s -1) conditions, mainly encountered during night-time hours, hourly values of H 2S were highly correlated with those of CO ( r2 = 0.75) and SO 2 ( r2 = 0.70), pointing to a common traffic source from catalytic converters. Annual mean concentrations are above the WHO recommendation for odor annoyance; hence, H 2S might play a role to the malodorous episodes that the city occasionally experiences. The high ambient H 2S levels might also be relevant to the implementation of preservation efforts for outdoor marble and limestone historical monuments that have been targeting SO 2 emissions as an atmospheric acidity source, since the measurements presented here suggest that about 19% of the annual sulfur (SO 2 + H 2S) emissions in Thessaloniki are in the form of H 2S.

  2. Hydrogen polysulfide (H2S n ) signaling along with hydrogen sulfide (H2S) and nitric oxide (NO).

    PubMed

    Kimura, Hideo

    2016-11-01

    Hydrogen sulfide (H2S) is a physiological mediator with various roles, including neuro-modulation, vascular tone regulation, and cytoprotection against ischemia-reperfusion injury, angiogenesis, and oxygen sensing. Hydrogen polysulfide (H2S n ), which possesses a higher number of sulfur atoms than H2S, recently emerged as a potential signaling molecule that regulates the activity of ion channels, a tumor suppressor, transcription factors, and protein kinases. Some of the previously reported effects of H2S are now attributed to the more potent H2S n . H2S n is produced by 3-mercaptopyruvate sulfurtransferase (3MST) from 3-mercaptopyruvate (3MP) and is generated by the chemical interaction of H2S with nitric oxide (NO). H2S n sulfhydrates (sulfurates) cysteine residues of target proteins and modifies their activity, whereas H2S sulfurates oxidized cysteine residues as well as reduces cysteine disulfide bonds. This review focuses on the recent progress made in studies concerning the production and physiological roles of H2S n and H2S.

  3. Esterase Activated Carbonyl Sulfide/Hydrogen Sulfide (H2S) Donors.

    PubMed

    Chauhan, Preeti; Bora, Prerona; Ravikumar, Govindan; Jos, Swetha; Chakrapani, Harinath

    2017-01-06

    Hydrogen sulfide (H2S) is a mediator of a number of cellular processes, and modulating cellular levels of this gas has emerged as an important therapeutic area. Localized generation of H2S is thus very useful but highly challenging. Here, we report pivaloyloxymethyl-based carbonothioates and carbamothioates that are activated by the enzyme, esterase, to generate carbonyl sulfide (COS), which is hydrolyzed to H2S.

  4. Visible-Light-Triggered Uncaging of Carbonyl Sulfide for Hydrogen Sulfide (H2S) Release.

    PubMed

    Sharma, Ajay Kumar; Nair, Mrutyunjay; Chauhan, Preeti; Gupta, Kavya; Saini, Deepak K; Chakrapani, Harinath

    2017-09-05

    Generation of hydrogen sulfide (H2S) is challenging and few methods are capable of localized delivery of this gas. Here, a boron dipyrromethene-based carbamothioate (BDP-H2S) that is uncaged by visible light of 470 nm to generate carbonyl sulfide (COS), which is rapidly hydrolyzed to H2S in the presence of carbonic anhydrase, a widely prevalent enzyme, is reported.

  5. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 250.215 Section 250.215 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... Contents of Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must accompany the...

  6. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550.215 Section 550.215 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... Information Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2S) information must...

  7. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550.215 Section 550.215 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... Information Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2S) information must...

  8. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550.215 Section 550.215 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... Information Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2S) information must...

  9. Bio-orthogonal "click-and-release" donation of caged carbonyl sulfide (COS) and hydrogen sulfide (H2S).

    PubMed

    Steiger, Andrea K; Yang, Yang; Royzen, Maksim; Pluth, Michael D

    2017-01-24

    Hydrogen sulfide (H2S) is an important biomolecule with high therapeutic potential. Here we leverage the inverse-electron demand Diels-Alder (IEDDA) click reaction between a thiocarbamate-functionalized trans-cyclooctene and a tetrazine to deliver carbonyl sulfide (COS), which is quickly converted to H2S by the uniquitous enzyme carbonic anhydrase (CA), thus providing a new strategy for bio-orthogonal COS/H2S donation.

  10. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 250.215 Section 250.215 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION... CONTINENTAL SHELF Plans and Information Contents of Exploration Plans (ep) § 250.215 What hydrogen...

  11. Hydrogen Sulfide (H2S) Releasing Agents: Chemistry and Biological Applications

    PubMed Central

    Zhao, Yu; Biggs, Tyler D.

    2014-01-01

    Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in the field. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of current available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawesson’s reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed. PMID:25019301

  12. Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)

    PubMed Central

    Sitdikova, Guzel F.; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M.; Hermann, Anton

    2014-01-01

    Introduction: Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. Aims: The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H2S on the channel as well as to recalculate and determine the H2S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions. Methods: Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H2S was measured with an anion selective electrode. Results: The concentration of H2S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H2S into account. The results indicate that from a concentration of 300 μM NaHS, only 11–13%, i.e., 34–41 μM is effective as H2S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H2S in ATP-containing solutions. PKA prevented the action of H2S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H2S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H2S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H2S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H2S was also observed in the presence of okadaic acid. Conclusions: Our results suggest that phosphorylation by PKG primes the channels for H2S activation and indicate that channel phosphorylation plays an important role in the response to H2S. PMID:25429270

  13. Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S).

    PubMed

    Sitdikova, Guzel F; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M; Hermann, Anton

    2014-01-01

    Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H2S on the channel as well as to recalculate and determine the H2S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions. Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H2S was measured with an anion selective electrode. The concentration of H2S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H2S into account. The results indicate that from a concentration of 300 μM NaHS, only 11-13%, i.e., 34-41 μM is effective as H2S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H2S in ATP-containing solutions. PKA prevented the action of H2S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H2S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H2S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H2S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H2S was also observed in the presence of okadaic acid. Our results suggest that phosphorylation by PKG primes the channels for H2S activation and indicate that channel phosphorylation plays an important role in the response to H2S.

  14. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 250.245 Section 250.245 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?...

  15. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 250.245 Section 250.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Development Operations Coordination Documents (docd) § 250.245 What hydrogen sulfide (H2S) information...

  16. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

  17. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

  18. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

  19. Hydrogen sulfide (H2S) - the third gas of interest for pharmacologists.

    PubMed

    Łowicka, Ewelina; Bełtowski, Jerzy

    2007-01-01

    Nitric oxide (NO) and carbon monoxide (CO) synthesized from L-arginine by NO synthase and from heme by heme oxygenase, respectively, are the well-known neurotransmitters and are also involved in the regulation of vascular tone. Recent studies suggest that hydrogen sulfide (H(2)S) is the third gaseous mediator in mammals. H(2)S is synthesized from L-cysteine by either cystathionine beta-synthase (CBS) or cystathionine gamma-lyase (CSE), both using pyridoxal 5'-phosphate (vitamin B(6)) as a cofactor. H(2)S stimulates ATP-sensitive potassium channels (K(ATP)) in the vascular smooth muscle cells, neurons, cardiomyocytes and pancreatic beta-cells. In addition, H(2)S may react with reactive oxygen and/or nitrogen species limiting their toxic effects but also, attenuating their physiological functions, like nitric oxide does. In contrast to NO and CO, H(2)S does not stimulate soluble guanylate cyclase. H(2)S is involved in the regulation of vascular tone, myocardial contractility, neurotransmission, and insulin secretion. H(2)S deficiency was observed in various animal models of arterial and pulmonary hypertension, Alzheimer's disease, gastric mucosal injury and liver cirrhosis. Exogenous H(2)S ameliorates myocardial dysfunction associated with the ischemia/reperfusion injury and reduces the damage of gastric mucosa induced by anti-inflammatory drugs. On the other hand, excessive production of H(2)S may contribute to the pathogenesis of inflammatory diseases, septic shock, cerebral stroke and mental retardation in patients with Down syndrome, and reduction of its production may be of potential therapeutic value in these states.

  20. A timeline of hydrogen sulfide (H2S) research: From environmental toxin to biological mediator.

    PubMed

    Szabo, Csaba

    2017-09-22

    The history of H2S - as an environmental toxin - dates back to 1700, to the observations of the Italian physician Bernardino Ramazzini, whose book "De Morbis Artificum Diatriba" described the painful eye irritation and inflammation of "sewer gas" in sewer workers. The gas has subsequently been identified as hydrogen sulfide (H2S), and opened three centuries of research into the biological roles of H2S. The current article highlights the key discoveries in the field of H2S research, including (a) the toxicological studies, which characterized H2S as an environmental toxin, and identified some of its modes of action, including the inhibition of mitochondrial respiration; (b) work in the field of bacteriology, which, starting in the early 1900s, identified H2S as a bacterial product - with subsequently defined roles in the regulation of periodontal disease (oral bacterial flora), intestinal epithelial cell function (enteral bacterial flora) as well as in the regulation of bacterial resistance to antibiotics; and (c), work in diverse fields of mammalian biology, which, starting in the 1940s, identified H2S as an endogenous mammalian enzymatic product, the functions of which - among others, in the cardiovascular and nervous system - have become subjects of intensive investigation for the last decade. The current review not only enumerates the key discoveries related to H2S made over the last three centuries, but also compiles the most frequently cited papers in the field which have been published over the last decade and highlights some of the current 'hot topics' in the field of H2S biology. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Hydrogen sulfide (H2S) and sour gas effects on the eye. A historical perspective.

    PubMed

    Lambert, Timothy William; Goodwin, Verona Marie; Stefani, Dennis; Strosher, Lisa

    2006-08-15

    The toxicology of hydrogen sulfide (H(2)S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98-99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little evidence of eye irritation following short-term exposures to H(2)S at concentrations up to 100ppm and that the H(2)S literature on the eye is a series of unsubstantiated claims reproduced in review articles dating back to the 1930s [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide: a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In this paper, we evaluated this claim through a historical review of the toxicology of the eye. Ramazzini noted the effects of sewer gas on the eye [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc. 1964. 98-99 pp.]. Lehmann experimentally showed eye effects in men at 70-90ppm H(2)S and also in animals [Lehmann K. Experimentalle Studien uber den Einfluss technisch und hygienisch wichtiger Gase und Dampfe auf den Organismus. Arch Hyg 1892;14:135-189]. In 1923, Sayers, Mitchell and Yant reported eye effects in animals and men at 50ppm H(2)S. Barthelemy showed eye effects in animals and men at 20ppm H(2)S [Barthelemy HL. Ten years' experience with industrial hygiene in connection with the manufacture of viscose rayon. J Ind Hyg Toxicol 1939;21:141-51]. Masure experimentally showed that H(2)S is the causative agent of eye impacts in animals and men [Masure R. La Keratoconjunctivite des filatures de viscose; etude clinique and experiementale. Rev Belge Pathol 1950;20:297-341]. Michal upon microscopic examination of the rat's cornea, found nuclear pyknosis, edema and separation of cells in

  2. Homocysteine, hydrogen sulfide (H2S) and NMDA-receptor in heart failure.

    PubMed

    Tyagi, Neetu; Mishra, Paras K; Tyagi, Suresh C

    2009-12-01

    Mitochondrial mechanism of oxidative stress and matrix metalloproteinase (MMP) activation was unclear. Our recent data suggested that MMPs are localized to mitochondria and activated by peroxynitrite, which causes cardiovascular remodeling and failure. Recently, we have demonstrated that elevated levels of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy) increase oxidative stress in the mitochondria. Although HHcy causes heart failure, interestingly, it is becoming very clear that Hcy can generate hydrogen sulfide (H2S), if the enzymes cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CGL) are present. H2S is a strong anti-oxidant and vasorelaxing agent. Paradoxically, it is interesting that Hcy, a precursor of H2S can be cardioprotective. The CGL is ubiquitous, while the CBS is not present in the vascular tissues. Therefore, under normal condition, only half of Hcy can be converted to H2S. However, there is strong potential for gene therapy of CBS to vascular tissue that can mitigate the detrimental effects of Hcy by converting it to H2S. This scenario is possible, if the activities of both the enzymes (CBS and CGL) are increased in tissues by gene therapy.

  3. Pharmacological investigation of hydrogen sulfide (H2S) contractile activity in rat detrusor muscle.

    PubMed

    Patacchini, Riccardo; Santicioli, Paolo; Giuliani, Sandro; Maggi, Carlo Alberto

    2005-02-21

    We have investigated the mechanism through which hydrogen sulfide (H2S) stimulates capsaicin-sensitive primary afferent neurons in the rat isolated urinary bladder. Sodium hydrogen sulfide (NaHS), a donor of H2S, produced concentration-dependent contractile responses (pEC50=3.5+/-0.1) that were unaffected by the transient receptor potential vanilloid receptor 1 (TRPV1) antagonist capsazepine (30 microM) and SB 366791 (10 microM) and by the N-type Ca2+ channel blocker omega-conotoxin GVIA (omega-CTX; 100 nM). In contrast, the unselective transient receptor potential (TRP) cation channels blocker ruthenium red (30 microM) almost abolished NaHS-induced contractions. Ruthenium red (30 microM) greatly reduced capsaicin-induced contractions, whereas it did not attenuate the contractile response to neurokinin A. The putative TRPV1 receptor antagonist iodo-resiniferatoxin, from 100 nM upward, produced agonist responses per se, and could not be tested against NaHS. We conclude that H2S either acts at TRPV1 receptorial sites unblocked by capsazepine or SB 366791, or stimulates a still unidentified transient receptor potential-like channel co-expressed with TRPV1 on sensory neurons.

  4. Inhibition and Promotion of Pyrolysis by Hydrogen Sulfide (H2S) and Sulfanyl Radical (SH).

    PubMed

    Zeng, Zhe; Altarawneh, Mohammednoor; Oluwoye, Ibukun; Glarborg, Peter; Dlugogorski, Bogdan Z

    2016-11-17

    This study resolves the interaction of sulfanyl radical (SH) with aliphatic (C1-C4) hydrocarbons, using CBS-QB3 based calculations. We obtained the C-H dissociation enthalpies and located the weakest link in each hydrocarbon. Subsequent computations revealed that, H abstraction by SH from the weakest C-H sites in alkenes and alkynes, except for ethylene, appears noticeably exothermic. Furthermore, abstraction of H from propene, 1-butene, and iso-butene displays pronounced spontaneity (i.e., ΔrG° < -20 kJ mol(-1) between 300-1200 K) due to the relatively weak allylic hydrogen bond. However, an alkyl radical readily abstracts H atom from H2S, with H2S acting as a potent scavenger for alkyl radicals in combustion processes. That is, these reactions proceed in the opposite direction than those involving SH and alkene or alkyne species, exhibiting shallow barriers and strong spontaneity. Our findings demonstrate that the documented inhibition effect of hydrogen sulfide (H2S) on pyrolysis of alkanes does not apply to alkenes and alkynes. During interaction with hydrocarbons, the inhibitive effect of H2S and promoting interaction of SH radical depend on the reversibility of the H abstraction processes. For the three groups of hydrocarbon, Evans-Polanyi plots display linear correlations between the bond dissociation enthalpies of the abstracted hydrogens and the relevant activation energies. In the case of methane, we demonstrated that the reactivity of SH radicals toward abstracting H atoms exceeds that of HO2 but falls below those of OH and NH2 radicals.

  5. Highly sensitive hydrogen sulfide (H2 S) gas sensors from viral-templated nanocrystalline gold nanowires

    NASA Astrophysics Data System (ADS)

    Moon, Chung Hee; Zhang, Miluo; Myung, Nosang V.; Haberer, Elaine D.

    2014-04-01

    A facile, site-specific viral-templated assembly method was used to fabricate sensitive hydrogen sulfide (H2S) gas sensors at room temperature. A gold-binding M13 bacteriophage served to organize gold nanoparticles into linear arrays which were used as seeds for subsequent nanowire formation through electroless deposition. Nanowire widths and densities within the sensors were modified by electroless deposition time and phage concentration, respectively, to tune device resistance. Chemiresistive H2S gas sensors with superior room temperature sensing performance were produced with sensitivity of 654%/ppmv, theoretical lowest detection limit of 2 ppbv, and 70% recovery within 9 min for 0.025 ppmv. The role of the viral template and associated gold-binding peptide was elucidated by removing organics using a short O2 plasma treatment followed by an ethanol dip. The template and gold-binding peptide were crucial to electrical and sensor performance. Without surface organics, the resistance fell by several orders of magnitude, the sensitivity dropped by more than a factor of 100 to 6%/ppmv, the lower limit of detection increased, and no recovery was detected with dry air flow. Viral templates provide a novel, alternative fabrication route for highly sensitive, nanostructured H2S gas sensors.

  6. Mechanisms of hydrogen sulfide (H2S) action on synaptic transmission at the mouse neuromuscular junction.

    PubMed

    Gerasimova, E; Lebedeva, J; Yakovlev, A; Zefirov, A; Giniatullin, R; Sitdikova, G

    2015-09-10

    Hydrogen sulfide (H2S) is a widespread gasotransmitter also known as a powerful neuroprotective agent in the central nervous system. However, the action of H2S in peripheral synapses is much less studied. In the current project we studied the modulatory effects of the H2S donor sodium hydrosulfide (NaHS) on synaptic transmission in the mouse neuromuscular junction using microelectrode technique. Using focal recordings of presynaptic response and evoked transmitter release we have shown that NaHS (300 μM) increased evoked end-plate currents (EPCs) without changes of presynaptic waveforms which indicated the absence of NaHS effects on sodium and potassium currents of motor nerve endings. Using intracellular recordings it was shown that NaHS increased the frequency of miniature end-plate potentials (MEPPs) without changing their amplitudes indicating a pure presynaptic effect. Furthermore, NaHS increased the amplitude of end-plate potentials (EPPs) without influencing the resting membrane potential of muscle fibers. L-cysteine, a substrate of H2S synthesis induced, similar to NaHS, an increase of EPC amplitudes whereas inhibitors of H2S synthesis (β-cyano-L-alanine and aminooxyacetic acid) had the opposite effect. Inhibition of adenylate cyclase using MDL 12,330A hydrochloride (MDL 12,330A) or elevation of cAMP level with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (pCPT-cAMP) completely prevented the facilitatory action of NaHS indicating involvement of the cAMP signaling cascade. The facilitatory effect of NaHS was significantly diminished when intracellular calcium (Ca(2+)) was buffered by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester (EGTA-AM). Activation of ryanodine receptors by caffeine or ryanodine increased acetylcholine release and prevented further action of NaHS on transmitter release, likely due to

  7. Mathematical modelling and simulation on the adsorption of Hydrogen Sulfide (H2S) gas

    NASA Astrophysics Data System (ADS)

    Zulkefli, N. N.; Masdar, M. S.; Isahak, W. R. W.; Jahim, J.; Majlan, E. H.; Rejab, S. A. M.; Lye, C. C.

    2017-06-01

    Hydrogen sulfide, H2S, a pollutant in biofuel gas, i.e., biohydrogen and biomethane, is produced at concentrations ranging from 100 ppm to 10,000 ppm and is recommended to be removed at the early stage of gas purification because it is known as a problematic compound. In this study, adsorption technologies show a promising technique to remove H2S from biofuel gas, which mainly depends on the operating parameters and adsorbent ability. In this study, the development of the models is important to investigate the fundamentals of H2S adsorption mechanism. The fitted mathematics model was performed by considering several assumptions made for fixed-bed adsorption, leading to the determination of the breakthrough curve by solving a set of partial differential equations (PDEs). The operating parameters were as follows: varied inlet concentration at 1000 ppm to 10,000 ppm, flow rate at 0.2 L/min to 0.6 L/min, length bed used at 10 cm to 30 cm, and pressure at 1.5 atm to 5 atm. The adsorption performance was also studied by using commercial activated carbon such as palm kernel shell (PKS-AC), coconut shell activated carbon (coconut shell-AC), and zeolite ZSM-5. To support the effectiveness of the mathematical models, the adsorption test was performed by loading the adsorbent into the fixed-bed adsorption column at an overall diameter of 6 cm and height of 30 cm. The system operated under room temperature, H2S inlet concentration of 1000 ppm, and varying flow rate as in the modelling for PKS-AC. As a result, in the modelling study, the inlet concentration effect was highest in adsorption capacity, breakthrough time, and exhaustion time. However, the increase of flow rate and length bed used only affected the breakthrough and exhaustion times but not adsorption capacity. The total pressure used did not affect adsorption performance. Coconut shell-AC shows longer exhaustion time compared with other adsorbents due to the less frequent changes of adsorbent. In the experimental

  8. Hydrogen sulfide (H2S) emission control by aerobic sulfate reduction in landfill

    NASA Astrophysics Data System (ADS)

    Long, Yuyang; Fang, Yuan; Shen, Dongsheng; Feng, Huajun; Chen, Ting

    2016-12-01

    H2S emissions from landfill sites resulting from sulfate reduction has become a serious human health and ecological safety issue. This study investigated H2S emission behavior and sulfate metabolism occurring in simulated landfills under different operating conditions. Under aerobic conditions, great attenuation of the original sulfate content (from around 6000 mg kg-1 dropped to below 800 mg kg-1) with corresponding accumulation of sulfides and elemental sulfur were observed, indicating that sulfate reduction processes were intense under such conditions. Analysis of the bacterial community in these landfills showed great abundance (1.10%) and diversity of sulfur reducing types, confirming their active involvement in this process. In particular, the total abundance of sulfate-reducing bacteria increased nearly 30 times under aerobic conditions, leading to the transformation of sulfate to sulfide and other reduced sulfur species. Although exposure to air promoted the accumulation of sulfide, it did not lead to an increase in H2S release in these landfills.

  9. Hydrogen sulfide (H2S) emission control by aerobic sulfate reduction in landfill

    PubMed Central

    Long, Yuyang; Fang, Yuan; Shen, Dongsheng; Feng, Huajun; Chen, Ting

    2016-01-01

    H2S emissions from landfill sites resulting from sulfate reduction has become a serious human health and ecological safety issue. This study investigated H2S emission behavior and sulfate metabolism occurring in simulated landfills under different operating conditions. Under aerobic conditions, great attenuation of the original sulfate content (from around 6000 mg kg−1 dropped to below 800 mg kg−1) with corresponding accumulation of sulfides and elemental sulfur were observed, indicating that sulfate reduction processes were intense under such conditions. Analysis of the bacterial community in these landfills showed great abundance (1.10%) and diversity of sulfur reducing types, confirming their active involvement in this process. In particular, the total abundance of sulfate-reducing bacteria increased nearly 30 times under aerobic conditions, leading to the transformation of sulfate to sulfide and other reduced sulfur species. Although exposure to air promoted the accumulation of sulfide, it did not lead to an increase in H2S release in these landfills. PMID:27909309

  10. Involvement of endogenous central hydrogen sulfide (H2S) in hypoxia-induced hypothermia in spontaneously hypertensive rats.

    PubMed

    Sabino, João Paulo J; Soriano, Renato N; Donatti, Alberto F; Fernandez, Rodrigo Restrepo; Kwiatkoski, Marcelo; Francescato, Heloísa D C; Coimbra, Terezila M; Branco, Luiz G S

    2017-02-01

    Spontaneously hypertensive rats (SHR) display autonomic imbalance and abnormal body temperature (Tb) adjustments. Hydrogen sulfide (H2S) modulates hypoxia-induced hypothermia, but its role in SHR thermoregulation is unknown. We tested the hypothesis that SHR display peculiar thermoregulatory response to hypoxia and that endogenous H2S overproduced in the caudal nucleus of the solitary tract (NTS) of SHR modulates this response. SHR and Wistar rats were microinjected into the fourth ventricle with aminooxyacetate (AOA, H2S-synthezing enzyme inhibitor) or sodium sulfide (Na2S, H2S donor) and exposed to normoxia (21% inspired O2) or hypoxia (10% inspired O2, 30 min). Tb was continuously measured, and H2S production rate was assessed in caudal NTS homogenates. In both groups, AOA, Na2S, or saline (i.e., control; 1 μL) did not affect euthermia. Hypoxia caused similar decreases in Tb in both groups. AOA presented a longer latency to potentiate hypoxic hypothermia in SHR. Caudal NTS H2S production rate was higher in SHR. We suggest that increased bioavailability of H2S in the caudal NTS of SHR enables the adequate modulation of excitability of peripheral chemoreceptor-activated NTS neurons that ultimately induce suppression of brown adipose tissue thermogenesis, thus accounting for the normal hypoxic hypothermia.

  11. Implications of Hydrogen Sulfide in Glucose Regulation: How H2S Can Alter Glucose Homeostasis through Metabolic Hormones

    PubMed Central

    Pichette, Jennifer

    2016-01-01

    Diabetes and its comorbidities continue to be a major health problem worldwide. Understanding the precise mechanisms that control glucose homeostasis and their dysregulation during diabetes are a major research focus. Hydrogen sulfide (H2S) has emerged as an important regulator of glucose homeostasis. This is achieved through its production and action in several metabolic and hormone producing organs including the pancreas, liver, and adipose. Of importance, H2S production and signaling in these tissues are altered during both type 1 and type 2 diabetes mellitus. This review first examines how H2S is produced both endogenously and by gastrointestinal microbes, with a particular focus on the altered production that occurs during obesity and diabetes. Next, the action of H2S on the metabolic organs with key roles in glucose homeostasis, with a particular focus on insulin, is described. Recent work has also suggested that the effects of H2S on glucose homeostasis goes beyond its role in insulin secretion. Several studies have demonstrated important roles for H2S in hepatic glucose output and adipose glucose uptake. The mechanism of H2S action on these metabolic organs is described. In the final part of this review, future directions examining the roles of H2S in other metabolic and glucoregulatory hormone secreting tissues are proposed. PMID:27478532

  12. Implications of Hydrogen Sulfide in Glucose Regulation: How H2S Can Alter Glucose Homeostasis through Metabolic Hormones.

    PubMed

    Pichette, Jennifer; Gagnon, Jeffrey

    2016-01-01

    Diabetes and its comorbidities continue to be a major health problem worldwide. Understanding the precise mechanisms that control glucose homeostasis and their dysregulation during diabetes are a major research focus. Hydrogen sulfide (H2S) has emerged as an important regulator of glucose homeostasis. This is achieved through its production and action in several metabolic and hormone producing organs including the pancreas, liver, and adipose. Of importance, H2S production and signaling in these tissues are altered during both type 1 and type 2 diabetes mellitus. This review first examines how H2S is produced both endogenously and by gastrointestinal microbes, with a particular focus on the altered production that occurs during obesity and diabetes. Next, the action of H2S on the metabolic organs with key roles in glucose homeostasis, with a particular focus on insulin, is described. Recent work has also suggested that the effects of H2S on glucose homeostasis goes beyond its role in insulin secretion. Several studies have demonstrated important roles for H2S in hepatic glucose output and adipose glucose uptake. The mechanism of H2S action on these metabolic organs is described. In the final part of this review, future directions examining the roles of H2S in other metabolic and glucoregulatory hormone secreting tissues are proposed.

  13. Potential biological chemistry of hydrogen sulfide (H2S) with the nitrogen oxides.

    PubMed

    Bruce King, S

    2013-02-01

    Hydrogen sulfide, an important gaseous signaling agent generated in numerous biological tissues, influences many physiological processes. This biological profile seems reminiscent of nitric oxide, another important endogenously synthesized gaseous signaling molecule. Hydrogen sulfide reacts with nitric oxide or oxidized forms of nitric oxide and nitric oxide donors in vitro to form species that display distinct biology compared to both hydrogen sulfide and NO. The products of these interesting reactions may include small-molecule S-nitrosothiols or nitroxyl, the one-electron-reduced form of nitric oxide. In addition, thionitrous acid or thionitrite, compounds structurally analogous to nitrous acid and nitrite, may constitute a portion of the reaction products. Both the chemistry and the biology of thionitrous acid and thionitrite, compared to nitric oxide or hydrogen sulfide, remain poorly defined. General mechanisms for the formation of S-nitrosothiols, nitroxyl, and thionitrous acid based upon the ability of hydrogen sulfide to act as a nucleophile and a reducing agent with reactive nitric oxide-based intermediates are proposed. Hydrogen sulfide reactivity seems extensive and could have an impact on numerous areas of redox-controlled biology and chemistry, warranting more work in this exciting and developing area.

  14. Fluorescent probes for hydrogen sulfide (H2S) and sulfane sulfur and their applications to biological studies.

    PubMed

    Shimamoto, Kazuhito; Hanaoka, Kenjiro

    2015-04-30

    Hydrogen sulfide (H2S), a toxic gas with the smell of rotten eggs, plays key roles in many physiological processes, including relaxation of vascular smooth muscles, mediation of neurotransmission, inhibition of insulin signaling, and regulation of inflammation. The most commonly used methods or detecting H2S are the methylene blue method and the electrode method, but these methods require destructive sampling, e.g., homogenization of biological samples. On the other hand, the fluorescence detection method has been widely used in biological studies to study the physiological roles of H2S, because this technology provides real-time, easy-to-use, nondestructive detection in live cells or tissues. Many selective fluorescent probes for H2S have been reported. Sulfane sulfur compounds contain divalent sulfur atoms bonded to other sulfur atom(s), as in persulfides (R-S-SH) and polysulfides (R-S-Sn-S-R). They are currently attracting increasing interest because one of the mechanisms of activity regulation of proteins by H2S is sulfhydration of cysteine residues (RSH → RSSH). Since H2S and sulfane sulfur are redox partners, they are very likely to coexist in biological systems, and from a reactivity point-of-view, sulfane sulfur seems likely to be much more effective than H2S in S-sulfhydration. Therefore, sulfane sulfur may be involved in mediating at least some of the biological activities of H2S. In this review, we summarize recent work on fluorescent probes selective for H2S and/or sulfane sulfur, and we briefly review their applications to biological studies.

  15. Exogenous Hydrogen Sulfide (H2S) Protects Alveolar Growth in Experimental O2-Induced Neonatal Lung Injury

    PubMed Central

    Vadivel, Arul; Alphonse, Rajesh S.; Ionescu, Lavinia; Machado, Desiree S.; O’Reilly, Megan; Eaton, Farah; Haromy, Al; Michelakis, Evangelos D.; Thébaud, Bernard

    2014-01-01

    Background Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, remains a major health problem. BPD is characterized by impaired alveolar development and complicated by pulmonary hypertension (PHT). Currently there is no specific treatment for BPD. Hydrogen sulfide (H2S), carbon monoxide and nitric oxide (NO), belong to a class of endogenously synthesized gaseous molecules referred to as gasotransmitters. While inhaled NO is already used for the treatment of neonatal PHT and currently tested for the prevention of BPD, H2S has until recently been regarded exclusively as a toxic gas. Recent evidence suggests that endogenous H2S exerts beneficial biological effects, including cytoprotection and vasodilatation. We hypothesized that H2S preserves normal alveolar development and prevents PHT in experimental BPD. Methods We took advantage of a recently described slow-releasing H2S donor, GYY4137 (morpholin-4-ium-4-methoxyphenyl(morpholino) phosphinodithioate) to study its lung protective potential in vitro and in vivo. Results In vitro, GYY4137 promoted capillary-like network formation, viability and reduced reactive oxygen species in hyperoxia-exposed human pulmonary artery endothelial cells. GYY4137 also protected mitochondrial function in alveolar epithelial cells. In vivo, GYY4137 preserved and restored normal alveolar growth in rat pups exposed from birth for 2 weeks to hyperoxia. GYY4137 also attenuated PHT as determined by improved pulmonary arterial acceleration time on echo-Doppler, pulmonary artery remodeling and right ventricular hypertrophy. GYY4137 also prevented pulmonary artery smooth muscle cell proliferation. Conclusions H2S protects from impaired alveolar growth and PHT in experimental O2-induced lung injury. H2S warrants further investigation as a new therapeutic target for alveolar damage and PHT. PMID:24603989

  16. Potential pitfalls of relying on hydrogen sulfide (H2S) production to identify Salmonella in feed

    USDA-ARS?s Scientific Manuscript database

    Salmonella can be difficult to assess and isolate in poultry feed due to stress, uneven distribution and poor growth. Previous studies have shown that several strains of Salmonella can be affected by environmental changes, resulting in H2S-negative colonies. This is a major concern, as H2S productio...

  17. THE IMPACT OF HYDROGEN SULFIDE (H2S) ON NEUROTRANSMITTER RELEASE FROM THE CAT CAROTID BODY

    PubMed Central

    Fitzgerald, Robert S.; Shirahata, Machiko; Chang, Irene; Kostuk, Eric; Kiihl, Samara

    2011-01-01

    Do cat carotid bodies (CBs) increase their release of acetylcholine and ATP in response to H2S? Two CBs, incubated in a Krebs Ringer bicarbonate solution at 37° C, exhibited a normal response to hypoxia -- increased release of acetylcholine (ACh) and ATP. They were challenged with several concentrations of Na2S, an H2S donor. H2S, a new gasotransmitter, is reported to open KATP channels. Under normoxic conditions the CBs reduced their release of ACh and ATP below control values. They responded identically to pinacidil, a well-known KATP channel opener. CB glomus cells exhibited a positive immunohistochemical signal for cystathione-β-synthetase, a H2S synthesizing enzyme, and for a subunit of the KATP channel. The data suggest that Na2S may have opened the glomus cells’ KATP channels, hyperpolarizing the cells, thus reducing their tonic release of ACh and ATP. Since during hypoxia H2S levels rise, the glomus cells responding very actively to hypoxia may be protected from over-exertion by the H2S opening of the KATP channels. PMID:21292043

  18. Vasodilator activity of hydrogen sulfide (H2S) in human mesenteric arteries.

    PubMed

    Materazzi, Serena; Zagli, Giovanni; Nassini, Romina; Bartolini, Ilenia; Romagnoli, Stefano; Chelazzi, Cosimo; Benemei, Silvia; Coratti, Andrea; De Gaudio, Angelo Raffaele; Patacchini, Riccardo

    2017-01-01

    The role of endogenous H2S has been highlighted as a gaseous transmitter. The vascular smooth muscle inhibitory effects of H2S have been characterized in isolated aorta and mesenteric arteries in rats and mice. Our study was aimed at investigating the vascular effects of H2S on human isolated mesenteric arteries and examining the underlying mechanisms involved. All experiments were performed on rings (4-8mm long) of human mesenteric arteries obtained from patients undergoing abdominal surgery. Ethical approval was obtained from the Ethics Committee of the University Hospital of the University of Florence (app. N. 2015/0024947). The effect of NaHS, an H2S donor, was determined using noradrenaline pre-contracted human isolated mesenteric rings. NaHS evoked a concentration-dependent relaxation (EC50 57μM). In contrast, homocysteine, an endogenous precursor of H2S, failed to affect human isolated mesenteric rings. Vasorelaxant response to NaHS was reduced by endothelium removal, application of the nitric oxide synthase inhibitor L-NAME and ODQ inhibitor of cyclic GMP. SQ 22536, an adenylate-cyclase inhibitor, failed to block NaHS-induced vasorelaxation. Inhibition of endogenous prostanoid production by indomethacin significantly reduced NaHS induced vasorelaxation. The role of potassium channels was also examined: blockers of the Ca(2+)-dependent potassium channel, charybdotoxin and apamin, failed to have any influence on the relaxant response to NaHS on this vascular tissue. In summary, H2S induced relaxation of isolated rings of human mesenteric arteries. Endothelium-dependent related mechanisms with the stimulation of ATP-sensitive potassium channels represents important cellular mechanisms for H2S effect on human mesenteric arteries. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Prevention of hydrogen sulfide (H2S)-induced mouse lethality and cytotoxicity by hydroxocobalamin (vitamin B(12a)).

    PubMed

    Truong, Don H; Mihajlovic, Aleksandra; Gunness, Patrina; Hindmarsh, Wayne; O'Brien, Peter J

    2007-12-05

    Recently, H(2)S (an environmental toxin) was proposed to induce cytotoxicity not only by inhibiting cytochrome oxidase but also by generating reactive oxygen species [Truong, D., Eghbal, M., Hindmarsh, W., Roth, Sh., O'Brien, P., 2006. Molecular mechanisms of hydrogen sulfide toxicity. Drug Metab. Rev. 38, 733-744]. In the following, evidence is presented supporting the use of hydroxocobalamin (vitamin B(12a)) as an antidote against H(2)S poisoning. More than 60% of the mice administered 35 mg/kg (0.63 mmol/kg) of NaSH (LD(90)) survived (at 24 h) when hydroxocobalamin (0.25 mmol/kg) was given after NaSH administration whereas less than 15% of the mice survived without hydroxocobalamin. Hydroxocobalamin (50-100 microM) or cobalt (50-100 microM) also prevented hepatocyte cytotoxicity induced by NaSH (500 microM). Furthermore, adding hydroxocobalamin 60 min later than NaSH still showed some protective activity. Catalytic amounts of hydroxocobalamin or cobalt added to a solution containing NaSH caused the disappearance of NaSH and induced oxygen uptake, indicative of NaSH oxidation and Co reduction, respectively.

  20. Hydrogen Sulfide Sequestration and Storage in Geothermal System: New Mitigation Strategy to Reduce H2S from the Atmosphere and Detect its Mineralization with Multiple Sulfur Isotopic Systematics

    NASA Astrophysics Data System (ADS)

    Marieni, C.; Stefansson, A.; Gudbrandsson, S.; Gunnarsson, I.; Aradottir, E. S.; Gunnarsson Robin, J.; Ono, S.

    2015-12-01

    Hydrogen sulfide (H2S) is one of the major components in geothermal fluids and is commonly emitted into the atmosphere from geothermal power plants causing potential environmental problems. Among several mitigation methods proposed to reduce the H2S emissions, is H2S sequestration into geothermal systems. Reykjavík Energy is undertaking a pilot project at Hellisheidi geothermal system (SW Iceland) called Sulfix project where H2S is being injected into the geothermal reservoir for permanent sequestration into pyrite. The SulFix project started its operation in June 2014: the soluble geothermal gases are dissolved in geothermal waste water, and injected at 8 bars into the high temperature reservoir (>200˚C) at 750 m below the wellhead. The reactions involving sulfur in the geothermal reservoir may be traced using sulfur fluid chemistry and multiple sulfur isotope systematics (32S, 33S, 34S and 36S), including mixing between the reservoir geothermal fluid and the injection fluid, sulfide mineralization and oxidation of sulfide to sulfate. In this study we investigated the multiple sulfur isotope systematics upon sulfide mineralization under geothermal conditions. High temperature flow through experiments were carried out in basaltic glass at 200-250°C and ~5 mmol/kg H2S to study the fluid-rock interaction. The results indicate that the sulfide mineralization occurs rapidly under geothermal conditions, highlighting the leaching rate of iron from the basaltic glass as the mineralization rate determining factor. Moreover, the formation of sulfide may be traced using the δ34S-Δ33S relationship in the fluids and pyrite formation - for example to determine if non-reactive mixing between the injection fluids and reservoir fluids occurs at Hellisheidi. The experimental results have been further supported by geochemical modeling involving multiple sulfur isotope fractionation between aqueous sulfide species and rocks upon basalt dissolution and secondary pyrite formation.

  1. Polysulfides (H2Sn) produced from the interaction of hydrogen sulfide (H2S) and nitric oxide (NO) activate TRPA1 channels

    PubMed Central

    Miyamoto, Ryo; Koike, Shin; Takano, Yoko; Shibuya, Norihiro; Kimura, Yuka; Hanaoka, Kenjiro; Urano, Yasuteru; Ogasawara, Yuki; Kimura, Hideo

    2017-01-01

    Hydrogen sulfide (H2S) exerts synergistic effects with another gaseous signaling molecule nitric oxide (NO) on ion channels and vasculature. However, the mechanism of the synergy is not well understood. Here, we show that the interaction between H2S and NO generates polysulfides (H2Sn), which activate transient receptor potential ankyrin 1 (TRPA1) channels. High performance liquid chromatography with tandem mass spectrometry analysis, along with the imaging of intracellular Ca2+ and H2Sn, showed that H2Sn and their effects were abolished by cyanolysis and by reducing substances such as dithiothreitol (DTT), cysteine, and glutathione (GSH). However, the effects of nitroxyl or nitrosopersulfide, other potential products of H2S and NO interaction, are not affected by cyanolysis or reducing substances. This study demonstrates that H2Sn are products of synergy between H2S and NO and provides a new insight into the signaling mechanisms. PMID:28378773

  2. The effects of hydrogen sulfide on the polymer electrolyte membrane fuel cell anode catalyst: H2S-Pt/C interaction products

    NASA Astrophysics Data System (ADS)

    Lopes, Thiago; Paganin, Valdecir A.; Gonzalez, Ernesto R.

    2011-08-01

    The performance of a polymer electrolyte membrane fuel cell (PEMFC) operating on a simulated hydrocarbon reformate is described. The anode feed stream consisted of 80% H2, ∼20% N2, and 8 ppm hydrogen sulfide (H2S). Cell performance losses are calculated by evaluating cell potential reduction due to H2S contamination through lifetime tests. It is found that potential, or power, loss under this condition is a result of platinum surface contamination with elemental sulfur. Electrochemical mass spectroscopy (EMS) and electrochemical techniques are employed, in order to show that elemental sulfur is adsorbed onto platinum, and that sulfur dioxide is one of the oxidation products. Moreover, it is demonstrated that a possible approach for mitigating H2S poisoning on the PEMFC anode catalyst is to inject low levels of air into the H2S-contaminated anode feeding stream.

  3. Sulfide stress corrosion study of a super martensitic stainless steel in H2S sour environments: Metallic sulfides formation and hydrogen embrittlement

    NASA Astrophysics Data System (ADS)

    Monnot, Martin; Nogueira, Ricardo P.; Roche, Virginie; Berthomé, Grégory; Chauveau, Eric; Estevez, Rafael; Mantel, Marc

    2017-02-01

    Thanks to their high corrosion resistance, super martensitic stainless steels are commonly used in the oil and gas industry, particularly in sour environments. Some grades are however susceptible to undergo hydrogen and mechanically-assisted corrosion processes in the presence of H2S, depending on the pH. The martensitic stainless steel EN 1.4418 grade exhibits a clear protective passive behavior with no sulfide stress corrosion cracking when exposed to sour environments of pH ≥ 4, but undergoes a steep decrease in its corrosion resistance at lower pH conditions. The present paper investigated this abrupt loss of corrosion resistance with electrochemical measurements as well as different physicochemical characterization techniques. Results indicated that below pH 4.0 the metal surface is covered by a thick (ca 40 μm) porous and defect-full sulfide-rich corrosion products layer shown to be straightforwardly related to the onset of hydrogen and sulfide mechanically-assisted corrosion phenomena.

  4. The novel mitochondria-targeted hydrogen sulfide (H2S) donors AP123 and AP39 protect against hyperglycemic injury in microvascular endothelial cells in vitro.

    PubMed

    Gerő, Domokos; Torregrossa, Roberta; Perry, Alexis; Waters, Alicia; Le-Trionnaire, Sophie; Whatmore, Jacqueline L; Wood, Mark; Whiteman, Matthew

    2016-11-01

    The development of diabetic vascular complications is initiated, at least in part, by mitochondrial reactive oxygen species (ROS) production in endothelial cells. Hyperglycemia induces superoxide production in the mitochondria and initiates changes in the mitochondrial membrane potential that leads to mitochondrial dysfunction. Hydrogen sulfide (H2S) supplementation has been shown to reduce the mitochondrial oxidant production and shows efficacy against diabetic vascular damage in vivo. However, the half-life of H2S is very short and it is not specific for the mitochondria. We have therefore evaluated two novel mitochondria-targeted anethole dithiolethione and hydroxythiobenzamide H2S donors (AP39 and AP123 respectively) at preventing hyperglycemia-induced oxidative stress and metabolic changes in microvascular endothelial cells in vitro. Hyperglycemia (HG) induced significant increase in the activity of the citric acid cycle and led to elevated mitochondrial membrane potential. Mitochondrial oxidant production was increased and the mitochondrial electron transport decreased in hyperglycemic cells. AP39 and AP123 (30-300nM) decreased HG-induced hyperpolarisation of the mitochondrial membrane and inhibited the mitochondrial oxidant production. Both H2S donors (30-300nM) increased the electron transport at respiratory complex III and improved the cellular metabolism. Targeting H2S to mitochondria retained the cytoprotective effect of H2S against glucose-induced damage in endothelial cells suggesting that the molecular target of H2S action is within the mitochondria. Mitochondrial targeting of H2S also induced >1000-fold increase in the potency of H2S against hyperglycemia-induced injury. The high potency and long-lasting effect elicited by these H2S donors strongly suggests that these compounds could be useful against diabetic vascular complications. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Reversion of stressed and unstressed hydrogen sulfide (H2S) producing strains of Salmonella in different media.

    USDA-ARS?s Scientific Manuscript database

    Salmonella can be difficult to assess and isolate in poultry feed due to uneven distribution and poor growth. Previous studies have shown that several strains of Salmonella can be affected by changes in environment, resulting in the growth of H2S-negative colonies. This is concerning, as H2S produ...

  6. Anxiolytic-like effect of hydrogen sulfide (H2S) in rats exposed and re-exposed to the elevated plus-maze and open field tests.

    PubMed

    Donatti, Alberto Ferreira; Soriano, Renato Nery; Leite-Panissi, Christie Ramos Andrade; Branco, Luiz G S; de Souza, Albert Schiaveto

    2017-03-06

    Hydrogen sulfide (H2S), an endogenous gaseous mediator, modulates many physiological functions in mammals but evidence of its involvement in emotional and behavioral aspects is currently scarce. We hypothesized that this gas plays a modulatory role in behavioral parameters in rats submitted to tests (for 5min) in the open field (OF) and elevated plus-maze (EPM - test and retest). Male Wistar rats (200-250g) were intraperitoneally injected with saline or Na2S (a H2S donor; 4, 8 and 12mg/kg) either once or for 8days, and submitted to the OF test or to the EPM test and retest. A third group (naïve) was not injected but exposed to the same experimental protocols. In the OF test, Na2S injected for 8days caused a decrease in self-cleaning (4, 8 and 12mg/kg) and freezing behaviors (8 and 12mg/kg), and a rise in the rate of line crossings in the central part of the arena (12mg/kg). In the EPM test and retest, Na2S at 12mg/kg for 8days caused an increase in the number of open arm entries and in the percentage of time spent on open arms. Our data are consistent with the notion that H2S exerts anxiolytic-like effects in rats submitted to the EPM and OF tests. Moreover, this gaseous modulator reduces aversive learning in the EPM retest. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Generation of DNA-damaging reactive oxygen species via the autoxidation of hydrogen sulfide under physiologically relevant conditions: chemistry relevant to both the genotoxic and cell signaling properties of H(2)S.

    PubMed

    Hoffman, Marjorie; Rajapakse, Anuruddha; Shen, Xiulong; Gates, Kent S

    2012-08-20

    Hydrogen sulfide (H(2)S) has long been known for its toxic properties; however, in recent years, evidence has emerged that this small, gaseous molecule may serve as an endogenous cell-signaling agent. Though perhaps surprising in light of its potential role as an endogenous signaling agent, a number of studies have provided evidence that H(2)S is a DNA-damaging mutagen. In the work reported here, the chemical mechanisms of DNA damage by H(2)S were examined. Using a plasmid-based DNA strand cleavage assay, we found that micromolar concentrations of H(2)S generated single-strand DNA cleavage. Mechanistic studies indicate that this process involved autoxidation of H(2)S to generate superoxide, hydrogen peroxide, and, ultimately, the well-known DNA-damaging agent hydroxyl radical via a trace metal-mediated Fenton-type reaction. Strand cleavage by H(2)S proceeded in the presence of physiological thiol concentrations, and the known byproducts of H(2)S oxidation such as thiosulfate, sulfite, and sulfate do not contribute to the strand cleavage process. However, initially generated oxidation products such as persulfide (S(2)(2-)) likely undergo rapid autoxidation reactions that contribute to the generation of superoxide. The potential relevance of autoxidation processes to the genotoxic and cell signaling properties of H(2)S is discussed.

  8. Measurements of hydrogen sulfide (H2S) using PTR-MS: calibration, humidity dependence, inter-comparison and results from field studies in an oil and gas production region

    NASA Astrophysics Data System (ADS)

    Li, R.; Warneke, C.; Graus, M.; Field, R.; Geiger, F.; Veres, P. R.; Soltis, J.; Li, S.-M.; Murphy, S. M.; Sweeney, C.; Pétron, G.; Roberts, J. M.; de Gouw, J.

    2014-06-01

    Natural gas production is associated with emissions of several trace gases, some of them classified as air toxics. While volatile organic compounds (VOCs) have received much attention, hydrogen sulfide (H2S) can also be of concern due to the known health impacts of exposure to this hazardous air pollutant. Here, we present quantitative, fast time-response measurements of H2S using Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS) instruments. An Ultra-Light-Weight PTR-MS (ULW-PTR-MS) in a mobile laboratory was operated for measurements of VOCs and H2S in a gas and oil field during the Uintah Basin Winter Ozone Study (UBWOS) 2012 campaign. Measurements of VOCs and H2S by a PTR-MS were also made at the Horse Pool ground site in the Uintah Basin during UBWOS 2013. The H2S measurement by PTR-MS is strongly humidity dependent because the proton affinity of H2S is only slightly higher than that of water. The H2S sensitivity of PTR-MS ranged between 0.6-1.4 ncps ppbv-1 (normalized counts per second/parts per billion by volume) during UBWOS 2013. We compare the humidity dependence determined in the laboratory with in-field calibrations and determine the H2S mixing ratios for the mobile and ground measurements. The PTR-MS measurements at Horse Pool are evaluated by comparison with simultaneous H2S measurements using a PTR Time-of-Flight MS (PTR-ToF-MS) and a Picarro cavity ring down spectroscopy (CRDS) instrument for H2S/CH4. On average 0.6 ± 0.3 ppbv H2S was present at Horse Pool during UBWOS 2013. The correlation between H2S and methane enhancements suggests that the source of H2S is associated with oil and gas extraction in the basin. Significant H2S mixing ratios of up to 9 ppmv downwind of storage tanks were observed during the mobile measurements. This study suggests that H2S emissions associated with oil and gas production can lead to short-term high levels close to point sources, and elevated background levels away from those sources. In addition, our work has

  9. Measurements of hydrogen sulfide (H2S) using PTR-MS: calibration, humidity dependence, inter-comparison and results from field studies in an oil and gas production region

    NASA Astrophysics Data System (ADS)

    Li, R.; Warneke, C.; Graus, M.; Field, R.; Geiger, F.; Veres, P. R.; Soltis, J.; Li, S.-M.; Murphy, S. M.; Sweeney, C.; Pétron, G.; Roberts, J. M.; de Gouw, J.

    2014-10-01

    Natural gas production is associated with emissions of several trace gases, some of them classified as air toxics. While volatile organic compounds (VOCs) have received much attention, hydrogen sulfide (H2S) can also be of concern due to the known health impacts of exposure to this hazardous air pollutant. Here, we present quantitative, fast time-response measurements of H2S using proton-transfer-reaction mass-spectrometry (PTR-MS) instruments. An ultra-light-weight PTR-MS (ULW-PTR-MS) in a mobile laboratory was operated for measurements of VOCs and H2S in a gas and oil field during the Uintah Basin Winter Ozone Study (UBWOS) 2012 campaign. Measurements of VOCs and H2S by a PTR-MS were also made at the Horse Pool ground site in the Uintah Basin during UBWOS 2013. The H2S measurement by PTR-MS is strongly humidity dependent because the proton affinity of H2S is only slightly higher than that of water. The H2S sensitivity of PTR-MS ranged between 0.6-1.4 ncps ppbv-1 during UBWOS 2013. We compare the humidity dependence determined in the laboratory with in-field calibrations and determine the H2S mixing ratios for the mobile and ground measurements. The PTR-MS measurements at Horse Pool are evaluated by comparison with simultaneous H2S measurements using a PTR time-of-flight MS (PTR-ToF-MS) and a Picarro cavity ring down spectroscopy (CRDS) instrument for H2S / CH4. On average 0.6 ± 0.3 ppbv H2S was present at Horse Pool during UBWOS 2013. The correlation between H2S and methane enhancements suggests that the source of H2S is associated with oil and gas extraction in the basin. Significant H2S mixing ratios of up to 9 ppmv downwind of storage tanks were observed during the mobile measurements. This study suggests that H2S emissions associated with oil and gas production can lead to short-term high levels close to point sources, and elevated background levels away from those sources. In addition, our work has demonstrated that PTR-MS can make reliable measurements of

  10. Cyclodextrin-Based Metal-Organic Nanotube as Fluorescent Probe for Selective Turn-On Detection of Hydrogen Sulfide in Living Cells Based on H2S-Involved Coordination Mechanism

    PubMed Central

    Xin, Xuelian; Wang, Jingxin; Gong, Chuanfang; Xu, Hai; Wang, Rongming; Ji, Shijie; Dong, Hanxiao; Meng, Qingguo; Zhang, Liangliang; Dai, Fangna; Sun, Daofeng

    2016-01-01

    Hydrogen sulfide (H2S) has been considered as the third biologically gaseous messenger (gasotransmitter) after nitric oxide (NO) and carbon monoxide (CO). Fluorescent detection of H2S in living cells is very important to human health because it has been found that the abnormal levels of H2S in human body can cause Alzheimer’s disease, cancers and diabetes. Herein, we develop a cyclodextrin-based metal-organic nanotube, CD-MONT-2, possessing a {Pb14} metallamacrocycle for efficient detection of H2S. CD-MONT-2′ (the guest-free form of CD-MONT-2) exhibits turn-on detection of H2S with high selectivity and moderate sensitivity when the material was dissolved in DMSO solution. Significantly, CD-MONT-2′ can act as a fluorescent turn-on probe for highly selective detection of H2S in living cells. The sensing mechanism in the present work is based on the coordination of H2S as the auxochromic group to the central Pb(II) ion to enhance the fluorescence intensity, which is studied for the first time. PMID:26911657

  11. Cyclodextrin-Based Metal-Organic Nanotube as Fluorescent Probe for Selective Turn-On Detection of Hydrogen Sulfide in Living Cells Based on H2S-Involved Coordination Mechanism.

    PubMed

    Xin, Xuelian; Wang, Jingxin; Gong, Chuanfang; Xu, Hai; Wang, Rongming; Ji, Shijie; Dong, Hanxiao; Meng, Qingguo; Zhang, Liangliang; Dai, Fangna; Sun, Daofeng

    2016-02-25

    Hydrogen sulfide (H2S) has been considered as the third biologically gaseous messenger (gasotransmitter) after nitric oxide (NO) and carbon monoxide (CO). Fluorescent detection of H2S in living cells is very important to human health because it has been found that the abnormal levels of H2S in human body can cause Alzheimer's disease, cancers and diabetes. Herein, we develop a cyclodextrin-based metal-organic nanotube, CD-MONT-2, possessing a {Pb14} metallamacrocycle for efficient detection of H2S. CD-MONT-2' (the guest-free form of CD-MONT-2) exhibits turn-on detection of H2S with high selectivity and moderate sensitivity when the material was dissolved in DMSO solution. Significantly, CD-MONT-2' can act as a fluorescent turn-on probe for highly selective detection of H2S in living cells. The sensing mechanism in the present work is based on the coordination of H2S as the auxochromic group to the central Pb(II) ion to enhance the fluorescence intensity, which is studied for the first time.

  12. Cyclodextrin-Based Metal-Organic Nanotube as Fluorescent Probe for Selective Turn-On Detection of Hydrogen Sulfide in Living Cells Based on H2S-Involved Coordination Mechanism

    NASA Astrophysics Data System (ADS)

    Xin, Xuelian; Wang, Jingxin; Gong, Chuanfang; Xu, Hai; Wang, Rongming; Ji, Shijie; Dong, Hanxiao; Meng, Qingguo; Zhang, Liangliang; Dai, Fangna; Sun, Daofeng

    2016-02-01

    Hydrogen sulfide (H2S) has been considered as the third biologically gaseous messenger (gasotransmitter) after nitric oxide (NO) and carbon monoxide (CO). Fluorescent detection of H2S in living cells is very important to human health because it has been found that the abnormal levels of H2S in human body can cause Alzheimer’s disease, cancers and diabetes. Herein, we develop a cyclodextrin-based metal-organic nanotube, CD-MONT-2, possessing a {Pb14} metallamacrocycle for efficient detection of H2S. CD-MONT-2‧ (the guest-free form of CD-MONT-2) exhibits turn-on detection of H2S with high selectivity and moderate sensitivity when the material was dissolved in DMSO solution. Significantly, CD-MONT-2‧ can act as a fluorescent turn-on probe for highly selective detection of H2S in living cells. The sensing mechanism in the present work is based on the coordination of H2S as the auxochromic group to the central Pb(II) ion to enhance the fluorescence intensity, which is studied for the first time.

  13. H2S exposure elicits differential expression of candidate genes in fish adapted to sulfidic and non-sulfidic environments.

    PubMed

    Tobler, Michael; Henpita, Chathurika; Bassett, Brandon; Kelley, Joanna L; Shaw, Jennifer H

    2014-09-01

    Disentangling the effects of plasticity, genetic variation, and their interactions on organismal responses to environmental stressors is a key objective in ecological physiology. We quantified the expression of five candidate genes in response to hydrogen sulfide (H2S) exposure in fish (Poecilia mexicana, Poeciliidae) from a naturally sulfide-rich environment as well as an ancestral, non-sulfidic population to test for constitutive and environmentally dependent population differences in gene expression patterns. Common garden raised individuals that had never encountered environmental H2S during their lifetime were subjected to short or long term H2S exposure treatments or respective non-sulfidic controls. The expression of genes involved in responses to H2S toxicity (cytochrome c oxidase, vascular endothelial growth factor, and cytochrome P450-2J6), H2S detoxification (sulfide:quinone oxidoreductase), and endogenous H2S production (cystathionine γ lyase) was determined in both gill and liver tissues by real time PCR. The results indicated complex changes in expression patterns that--depending on the gene--not only differed between organs and populations, but also on the type of H2S exposure. Populations differences, both constitutive and H2S exposure dependent (i.e., plastic), in gene expression were particularly evident for sulfide:quinone oxidoreductase, vascular endothelial growth factor, and to a lesser degree for cytochrome P450-2J6. Our study uncovered putatively adaptive modifications in gene regulation that parallel previously documented adaptive changes in phenotypic traits.

  14. VEGFR2 Functions As an H2S-Targeting Receptor Protein Kinase with Its Novel Cys1045–Cys1024 Disulfide Bond Serving As a Specific Molecular Switch for Hydrogen Sulfide Actions in Vascular Endothelial Cells

    PubMed Central

    Tao, Bei-Bei; Liu, Shu-Yuan; Zhang, Cai-Cai; Fu, Wei; Cai, Wen-Jie; Wang, Yi; Shen, Qing; Wang, Ming-Jie; Chen, Ying; Zhang, Li-Jia; Zhu, Yi-Zhun

    2013-01-01

    Abstract Aims: The potential receptor for hydrogen sulfide (H2S) remains unknown. Results: H2S could directly activate vascular endothelial growth factor receptor 2 (VEGFR2) and that a small interfering RNA (siRNA)-mediated knockdown of VEGFR2 inhibited H2S-induced migration of human vascular endothelial cells. H2S promoted angiogenesis in Matrigel plug assay in mice and this effect was attenuated by a VEGF receptor inhibitor. Using tandem mass spectrometry (MS), we identified a new disulfide complex located between Cys1045 and Cys1024 within VEGFR2 that was labile to H2S-mediated modification. Kinase activity of the mutant VEGFR2 (C1045A) devoid of the Cys1045–Cys1024 disulfide bond was significantly higher than wild-type VEGFR2. Transfection with vectors expressing VEGFR2 (C1045A) caused a significant increase in cell migration, while the migration-promoting effect of H2S disappeared in the cells transfected with VEGFR2 (C1045A). Therefore, the Cys1045–Cys1024 disulfide bond serves as an intrinsic inhibitory motif and functions as a molecular switch for H2S. The formation of the Cys1045–Cys1024 disulfide bond disrupted the integrity of the active conformation of VEGFR2. Breaking the Cys1045–Cys1024 disulfide bond recovered the active conformation of VEGFR2. This motif was prone to a nucleophilic attack by H2S via an interaction of their frontier molecular orbitals. siRNA-mediated knockdown of cystathionine γ-lyase attenuated migration of vascular endothelial cells induced by VEGF or moderate hypoxia. Innovation and Conclusion: The study provides the first piece of evidence of a molecular switch in H2S-targeting receptor protein kinase in H2S-induced angiogenesis and that may be applicable to additional kinases containing functionally important disulfide bonds in mediating various H2S actions. Antioxid. Redox Signal. 19, 448–464. PMID:23199280

  15. Impact of fluctuations in gaseous H2S concentrations on sulfide uptake by sewer concrete: The effect of high H2S loads.

    PubMed

    Sun, Xiaoyan; Jiang, Guangming; Bond, Philip L; Keller, Jurg

    2015-09-15

    The acid production from the oxidation of hydrogen sulfide (H2S) in sewer air results in serious corrosion of exposed concrete surfaces in sewers. Large fluctuations of gaseous H2S concentrations occur in sewers due to the diurnal profiles of sewage flow and retention times and the necessity of intermittent pumping of sewage from pressure pipes into gravity pipes. How the high concentrations of H2S due to these events may affect H2S uptake and subsequent corrosion by concrete sewers is largely unknown. This study determined the effect of short- and long-term increases in H2S levels on the sulfide uptake rate (SUR) of concrete surfaces with an active corrosion layer. The results showed that during the high load situation the SUR increased significantly but then decreased (compared to the baseline SUR) by about 7-14% and 41-50% immediately after short- and long-term H2S high-load periods, respectively. For both exposure conditions, the SUR gradually (over several hours) recovered to approximately 90% of the baseline SUR. Further tests suggest multiple factors may contribute to the observed decrease of SUR directly after the high H2S load. This includes the temporary storage of elemental sulfur in the corrosion layer and inhibition of sulfide oxidizing bacteria (SOB) due to high H2S level and temporary acid surge. Additionally, the delay of the corrosion layer to fully recover the SUR after the high H2S load suggests that there is a longer-term inhibitive effect of the high H2S levels on the activity of the SOB in the corrosion layer. Due to the observed activity reductions, concrete exposed to occasional short-term high H2S load periods had an overall lower H2S uptake compared to concrete exposed to constant H2S levels at the same average concentration. To accurately predict H2S uptake by sewer concrete and hence the likely maximum corrosion rates, a correction factor should be adopted for the H2S fluctuations when average H2S levels are used in the prediction.

  16. Hydrogen sulfide (H2S) attenuates uranium-induced acute nephrotoxicity through oxidative stress and inflammatory response via Nrf2-NF-κB pathways.

    PubMed

    Zheng, Jifang; Zhao, Tingting; Yuan, Yan; Hu, Nan; Tang, Xiaoqing

    2015-12-05

    As an endogenous gaseous mediator, H2S exerts anti-oxidative, anti-inflammatory and cytoprotective effects in kidneys. This study was designed to investigate the protective effect of H2S against uranium-induced nephrotoxicity in adult SD male rats after in vivo effect of uranium on endogenous H2S formation was explored in kidneys. The levels of endogenous H2S and H2S-producing enzymes (CBS and CSE) were measured in renal homogenates from rats intoxicated by an intraperitoneally (i.p.) injection of uranyl acetate at a single dose of 2.5, 5 or 10 mg/kg. In rats injected i.p. with uranyl acetate (5 mg/kg) or NaHS (an H2S donor, 28 or 56 μmol/kg) alone or in combination, we determined biochemical parameters and histopathological alteration to assess kidney function, examined oxidative stress markers, and investigated Nrf2 and NF-κB pathways in kidney homogenates. The results suggest that uranium intoxication in rats decreased endogenous H2S generation as well as CBS and CSE protein expression. NaHS administration in uranium-intoxicated rats ameliorated the renal biochemical indices and histopathological effects, lowered MDA accumulation, and restored GSH level and anti-oxidative enzymes activities like SOD, CAT, GPx and GST. NaHS treatment in uranium-intoxicated rats activated uranium-inhibited protein expression and nuclear translocation of transcription factor Nrf2, which increased protein expression of downstream target-Nrf2 genes HO-1, NQO-1, GCLC, and TXNRD-1. NaHS administration in uranium-intoxicated rats inhibited uranium-induced nuclear translocation and phosphorylation of transcription factor κB/p65, which decreased protein expression of target-p65 inflammatory genes TNF-α, iNOS, and COX-2. Taken together, these data implicate that H2S can afford protection to rat kidneys against uranium-induced adverse effects through induction of antioxidant defense by activating Nrf2 pathway and reduction of inflammatory response by suppressing NF-κB pathway

  17. S-Transnitrosation reactions of hydrogen sulfide (H2S/HS(-)/S(2-)) with S-nitrosated cysteinyl thiols in phosphate buffer of pH 7.4: Results and review of the literature.

    PubMed

    Tsikas, Dimitrios; Böhmer, Anke

    2017-05-01

    Cysteine (CysSH) and its derivatives including N-acetylcysteine (NAC) and glutathione (GSH), and cysteine residues in proteins and enzymes are nitrosated with nitric oxide (NO) reaction products such as N2O3 to form S-nitrosated cysteine thiols (RCysSNO). RCysSNO undergo with cysteine thiols (RCysSH) S-transnitrosation reactions, thereby transferring reversibly their nitrosyl ((+)NO) group to RCysSH to form RCysSNO. (•)NO release from RCysSNO and S-transnitrosation are considered the most important features and signalling pathways of RCysSNO. Hydrogen sulfide (H2S: pKa1, 7; HS(-): pKa2, 12.9) is an endogenous product of cysteine metabolism. We hypothesized that RCysSNO would also undergo S-transnitrosation reaction with H2S/HS(-)/S(2-) to form thionitrite (ONS(-)), the smallest S-nitrosated thiol. This article describes spectrophotometric and mass spectrometric investigations of S-transnitrosation reactions in phosphate buffered saline (PBS) of pH 7.4 between H2S/HS(-)/S(2-) (supplied as Na2S) and S-nitrosoglutathione (GSNO), S-nitroso-l-cysteine (CysSNO), S-nitroso-N-acetyl-l-cysteine (SNAC), and the synthetic S-nitroso-N-acetyl-l-cysteine ethyl ester (SNACET). For comparison, we also investigated the reactions of H2S/HS(-)/S(2-) with NO(+)BF4(-) and NO2(+)BF4(-), direct ON(+) and O2N(+) donors, respectively, and assumed formation of ONS(-) and thionitrate (O2NS(-)), respectively. Addition of Na2S (at 1 mM) to buffered RCysSNO solutions resulted in decreases of the absorbance at 340 nm and concomitant increases in the absorbance at 410 nm depending upon the nature and concentration of RCysSNO (range, 25-1000 μM). The reactivity order of RCysSNO against H2S/HS(-)/S(2-) was: CysSNO > SNACET > GSNO > SNAC. Our spectrophotometric and GC-MS analyses indicate that H2S/HS(-)/S(2-) and RCysSNO undergo multiple reactions. Major final reaction products were found to be nitrite and nitrate. ONS(-) and O2NS(-) were not detected by GC-MS, suggesting rapid and

  18. Diffusible gas transmitter signaling in the copepod crustacean Calanus finmarchicus: identification of the biosynthetic enzymes of nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) using a de novo assembled transcriptome.

    PubMed

    Christie, Andrew E; Fontanilla, Tiana M; Roncalli, Vittoria; Cieslak, Matthew C; Lenz, Petra H

    2014-06-01

    Neurochemical signaling is a major component of physiological/behavioral control throughout the animal kingdom. Gas transmitters are perhaps the most ancient class of molecules used by nervous systems for chemical communication. Three gases are generally recognized as being produced by neurons: nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S). As part of an ongoing effort to identify and characterize the neurochemical signaling systems of the copepod Calanus finmarchicus, the biomass dominant zooplankton in much of the North Atlantic Ocean, we have mined a de novo assembled transcriptome for sequences encoding the neuronal biosynthetic enzymes of these gases, i.e. nitric oxide synthase (NOS), heme oxygenase (HO) and cystathionine β-synthase (CBS), respectively. Using Drosophila proteins as queries, two NOS-, one HO-, and one CBS-encoding transcripts were identified. Reverse BLAST and structural analyses of the deduced proteins suggest that each is a true member of its respective enzyme family. RNA-Seq data collected from embryos, early nauplii, late nauplii, early copepodites, late copepodites and adults revealed the expression of each transcript to be stage specific: one NOS restricted primarily to the embryo and the other was absent in the embryo but expressed in all other stages, no CBS expression in the embryo, but present in all other stages, and HO expressed across all developmental stages. Given the importance of gas transmitters in the regulatory control of a number of physiological processes, these data open opportunities for investigating the roles these proteins play under different life-stage and environmental conditions in this ecologically important species.

  19. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.808 Section 250.808... Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown, as defined in § 250.490 of this...

  20. Suicide with hydrogen sulfide.

    PubMed

    Sams, Ralph Newton; Carver, H Wayne; Catanese, Charles; Gilson, Thomas

    2013-06-01

    This presentation will address the recent rise of suicide deaths resulting from the asphyxiation by hydrogen sulfide (H2S) gas.Hydrogen sulfide poisoning has been an infrequently encountered cause of death in medical examiner practice. Most H2S deaths that have been reported occurred in association with industrial exposure.More recently, H2S has been seen in the commission of suicide, particularly in Japan. Scattered reports of this phenomenon have also appeared in the United States.We have recently observed 2 intentional asphyxial deaths in association with H2S. In both cases, the decedents committed suicide in their automobiles. They generated H2S by combining a sulfide-containing tree spray with toilet bowl cleaner (with an active ingredient of hydrogen chloride acid). Both death scenes prompted hazardous materials team responses because of notes attached to the victims' car windows indicating the presence of toxic gas. Autopsy findings included discoloration of lividity and an accentuation of the gray matter of the brain. Toxicology testing confirmed H2S exposure with the demonstration of high levels of thiosulfate in blood.In summary, suicide with H2S appears to be increasing in the United States.

  1. The New Low Value for the Second Dissociation Constant for H2S: Its History, Its Best Value, and Its Impact on the Teaching of Sulfide Equilibria.

    ERIC Educational Resources Information Center

    Myers, Rollie J.

    1986-01-01

    Discusses the historical development of a new value of the second dissociation constant (K2) for hydrogen sulfide (H2S). Describes the differences between the traditional high values for K2. Suggests modification of teaching about sulfide equilibria in light of the new low value for K2. (TW)

  2. The New Low Value for the Second Dissociation Constant for H2S: Its History, Its Best Value, and Its Impact on the Teaching of Sulfide Equilibria.

    ERIC Educational Resources Information Center

    Myers, Rollie J.

    1986-01-01

    Discusses the historical development of a new value of the second dissociation constant (K2) for hydrogen sulfide (H2S). Describes the differences between the traditional high values for K2. Suggests modification of teaching about sulfide equilibria in light of the new low value for K2. (TW)

  3. Reaction of the C3(X(1)Σg (+)) carbon cluster with H2S(X(1)A1), hydrogen sulfide: photon-induced formation of C3S, tricarbon sulfur.

    PubMed

    Roehr, Nathan P; Szczepanski, Jan; Fu, Yi; Polfer, Nicolas C; Vala, Martin

    2014-11-28

    In this paper we report on the neutral-neutral reaction of the C3 carbon cluster with H2S in solid inert argon at 12 K, conditions that mimic, in part, the surfaces of interstellar grains. In the first step of the reaction, a C3•H2S complex is formed via an almost barrierless entrance addition mechanism. This complex, stabilized by an estimated 7.45 kJ/mol (CCSD(T)/aug-cc-pVTZ//B3LYP/6-311++G(d,p) level), is formed by the interaction of a terminal carbon of C3 with a hydrogen in H2S. This con-covalent complex displays a band at 2044.1 cm(-1) observed via Fourier transform infrared absorption spectroscopy. With the help of the MP2/aug-ccpVDZ level method, this band is assigned to the CC asymmetric vibration mode. When the complex is exposed to UV-visible photons (hν < 5.5 eV) the tricarbon sulfur C3S molecule is identified, based on the appearance of a characteristic CC stretching band at 2047.5 cm(-1). Calculated ground-state potential energy surfaces also confirm the concomitant formation of molecular H2. This facile reaction pathway involves an attainable transition state of 174.4 kJ/mol. Conversely, competing lower-energy reaction pathways that would lead to the generation of H2C3S (propadienethione), or C2H2 (acetylene) and CS, involve much more complex, multi-stage pathways, and are not observed experimentally.

  4. Reaction of the C3(X1Σg+) carbon cluster with H2S(X1A1), hydrogen sulfide: Photon-induced formation of C3S, tricarbon sulfur

    NASA Astrophysics Data System (ADS)

    Roehr, Nathan P.; Szczepanski, Jan; Fu, Yi; Polfer, Nicolas C.; Vala, Martin

    2014-11-01

    In this paper we report on the neutral-neutral reaction of the C3 carbon cluster with H2S in solid inert argon at 12 K, conditions that mimic, in part, the surfaces of interstellar grains. In the first step of the reaction, a C3•H2S complex is formed via an almost barrierless entrance addition mechanism. This complex, stabilized by an estimated 7.45 kJ/mol (CCSD(T)/aug-cc-pVTZ//B3LYP/6-311++G(d,p) level), is formed by the interaction of a terminal carbon of C3 with a hydrogen in H2S. This con-covalent complex displays a band at 2044.1 cm-1 observed via Fourier transform infrared absorption spectroscopy. With the help of the MP2/aug-ccpVDZ level method, this band is assigned to the CC asymmetric vibration mode. When the complex is exposed to UV-visible photons (hν < 5.5 eV) the tricarbon sulfur C3S molecule is identified, based on the appearance of a characteristic CC stretching band at 2047.5 cm-1. Calculated ground-state potential energy surfaces also confirm the concomitant formation of molecular H2. This facile reaction pathway involves an attainable transition state of 174.4 kJ/mol. Conversely, competing lower-energy reaction pathways that would lead to the generation of H2C3S (propadienethione), or C2H2 (acetylene) and CS, involve much more complex, multi-stage pathways, and are not observed experimentally.

  5. Hydrogen sulfide and translational medicine

    PubMed Central

    Guo, Wei; Cheng, Ze-yu; Zhu, Yi-zhun

    2013-01-01

    Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations. PMID:24096643

  6. Criegee intermediate-hydrogen sulfide chemistry at the air/water interface† †Electronic supplementary information (ESI) available: Radial distribution functions for the H2S–H2O and CH2OO–H2O interactions; probability distributions P(θ 1,θ 2) for H2S at the air–water interface; videos of trajectories of the BOMD simulations for the concerted and stepwise reactions between CH2OO and H2S at the air/water interface; BLYP/aug-cc-pVTZ-optimized geometries of key stationary points for the gas-phase reactions of CH2OO with H2S and H2S–H2O, respectively. See DOI: 10.1039/c7sc01797a Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.

    PubMed Central

    Kumar, Manoj; Zhong, Jie

    2017-01-01

    We carry out Born–Oppenheimer molecular dynamic simulations to show that the reaction between the smallest Criegee intermediate, CH2OO, and hydrogen sulfide (H2S) at the air/water interface can be observed within few picoseconds. The reaction follows both concerted and stepwise mechanisms with former being the dominant reaction pathway. The concerted reaction proceeds with or without the involvement of one or two nearby water molecules. An important implication of the simulation results is that the Criegee-H2S reaction can provide a novel non-photochemical pathway for the formation of a C–S linkage in clouds and could be a new oxidation pathway for H2S in terrestrial, geothermal and volcanic regions.

  7. Sulfidation Kinetics of Natural Chromite Ore Using H2S Gas

    NASA Astrophysics Data System (ADS)

    Ahmad, Sazzad; Rhamdhani, M. Akbar; Pownceby, Mark I.; Bruckard, Warren J.

    2015-04-01

    The kinetics and mechanism of natural chromite (FeCr2O4) sulfidation using 5 pct H2S (balance Ar) gas were studied in the temperature range 1173 K to 1473 K (900 °C to 1200 °C). Reaction products were examined using combined X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Results indicated the formation of an outer sulfide-rich layer comprising mixed (Fe,Cr)1- x S and (Cr,Fe)1- x S phases, underlain by a cation-depleted diffusion zone. The kinetics investigation indicated that the reaction rate increased with increasing temperature and that the sulfidation of chromite followed a shrinking unreacted core model. It is proposed that Cr3+ cation diffusion through the reaction product was the rate controlling step with an apparent activation energy of 166 ± 4 kJ mol-1. The calculated activation energy lies between the activation energy for Fe2+ and Cr3+ diffusion through pure chromite spinel and Fe-Cr alloy. Possible reasons for the discrepancy from pure chromite are expected to be the presence of minor Al and Mg in the natural chromite sample, and the partial pressure of oxygen under the reaction conditions used.

  8. Synergism between hydrogen sulfide (H(2)S) and nitric oxide (NO) in vasorelaxation induced by stonustoxin (SNTX), a lethal and hypotensive protein factor isolated from stonefish Synanceja horrida venom.

    PubMed

    Liew, H C; Khoo, H E; Moore, P K; Bhatia, M; Lu, J; Moochhala, S M

    2007-04-10

    Stonustoxin (SNTX) is a 148 kDa, dimeric, hypotensive and lethal protein factor isolated from the venom of the stonefish Synanceja horrida. SNTX (10-320 ng/ml) progressively causes relaxation of endothelium-intact, phenylephrine (PE)-precontracted rat thoracic aortic rings. The SNTX-induced vasorelaxation was inhibited by L-N(G)-nitro arginine methyl ester (L-NAME), suggesting that nitric oxide (NO) contributes to the SNTX-induced response. Interestingly, D, L-proparglyglycine (PAG) and beta-cyano-L-alanine (BCA), irreversible and competitive inhibitors of cystathionine-gamma-lyase (CSE) respectively, also inhibited SNTX-induced vasorelaxation, indicating that H(2)S may also play a part in the effect of SNTX. The combined use of L-NAME with PAG or BCA showed that H(2)S and NO act synergistically in effecting SNTX-induced vasorelaxation.

  9. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  10. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  11. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  12. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in...

  13. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in...

  14. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in...

  15. Medical Functions of Hydrogen Sulfide.

    PubMed

    Olas, Beata

    2016-01-01

    Hydrogen sulfide (H(2)S) is a gasomediator synthesized from L- and D-cysteine in various tissues. It is involved in a number of physiological and pathological processes. H(2)S exhibits antiatherosclerotic, vasodilator, and proangiogenic properties, and protects the kidney and heart from damage following ischemia/reperfusion injury. H(2)S donors may be natural or synthetic, and may be used for the safe treatment of a wide range of diseases. This review article summarizes the current state of knowledge of the therapeutic function of H(2)S.

  16. Identification of nickel sulfides on Ni-YSZ cermet exposed to H 2 fuel containing H 2S using Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Dong, Jian; Cheng, Zhe; Zha, Shaowu; Liu, Meilin

    Ni-YSZ cermet was exposed to hydrogen containing different concentrations of H 2S to identify the phases formed under various conditions using Raman spectroscopy and X-ray diffraction (XRD). For Ni-YSZ samples exposed to hydrogen containing 100 ppm H 2S at 727 °C for 5 days, thermodynamic calculations indicate that Ni-YSZ would be stable and XRD analysis was unable to detect any changes. However, the vibration modes of Ni 3S 2 were detected using Raman spectroscopy, suggesting that Raman spectroscopy could be a powerful tool for in situ study of sulfur poisoning of SOFC anodes. For Ni-YSZ cermet exposed to hydrogen containing 10% H 2S at 950 °C for 5 days, Ni was converted to nickel sulfide, and vibration modes of NiS were detected using Raman spectroscopy.

  17. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 005 www.epa.gov / iris TOXICOLOGICAL REVIEW OF HYDROGEN SULFIDE ( CAS No . 7783 - 06 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been

  18. Hydrogen sulfide and vascular relaxation.

    PubMed

    Sun, Yan; Tang, Chao-Shu; DU, Jun-Bao; Jin, Hong-Fang

    2011-11-01

    To review the vasorelaxant effects of hydrogen sulfide (H(2)S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved. The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and "vascular relaxation". Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected. H(2)S plays an important role in the regulation of cardiovascular tone. The vasomodulatory effects of H(2)S depend on factors including concentration, species and tissue type. The H(2)S donor, sodium hydrosulfide (NaHS), causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner. This effect was more pronounced than that observed in pulmonary arterial rings. The expression of K(ATP) channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings. H(2)S is involved in the pathogenesis of a variety of cardiovascular diseases. Downregulation of the endogenous H(2)S pathway is an important factor in the pathogenesis of cardiovascular diseases. The vasorelaxant effects of H(2)S have been shown to be mediated by activation of K(ATP) channels in vascular smooth muscle cells and via the induction of acidification due to activation of the Cl(-)/HCO(3)(-) exchanger. It is speculated that the mechanisms underlying the vasoconstrictive function of H(2)S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation. H(2)S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.

  19. Characterization of recycled rubber media for hydrogen sulphide (H2S) control.

    PubMed

    Wang, Ning; Park, Jaeyoung; Evans, Eric A; Ellis, Timothy G

    2014-01-01

    Hydrogen sulphide (H2S) adsorption capacities on recycled rubber media, tyre-derived rubber particle (TDRP), and other rubber material (ORM) have been evaluated. As part of the research, densities, moisture contents, and surface properties of TDRP and ORM have been determined. The research team findings show that TDRP and ORM are more particulate in nature and not highly porous-like activated carbon. The characteristics of surface area, pore size, and moisture content support chemisorption on the macrosurface rather than physical adsorption in micropores. For example, moisture content is essential for H2S adsorption on ORM, and an increase in moisture content results in an increase in adsorption capacity.

  20. High-dose hydroxocobalamin administered after H2S exposure counteracts sulfide-poisoning-induced cardiac depression in sheep.

    PubMed

    Haouzi, Philippe; Chenuel, Bruno; Sonobe, Takashi

    2015-01-01

    Severe H2S poisoning leads to death by rapid respiratory and cardiac arrest, the latter can occur within seconds or minutes in severe forms of intoxication. To determine the time course and the nature of H2S-induced cardiac arrest and the effects of high-dose hydroxocobalamin administered after the end of sulfide exposure. NaHS was infused in 16 sedated mechanically ventilated sheep to reach concentrations of H2S in the blood, which was previously found to lead to cardiac arrest within minutes following the cessation of H2S exposure. High-dose hydroxocobalamin (5 g) or saline solution was administered intravenously, 1 min after the cessation of NaHS infusion. All animals were still alive at the cessation of H2S exposure. Three animals (18%) presented a cardiac arrest within 90 s and were unable to receive any antidote or vehicle. In the animals that survived long enough to receive either hydroxocobalamin or saline, 71% (5/7) died in the control group by cardiac arrest within 10 min. In all instances, cardiac arrest was the result of a pulseless electrical activity (PEA). In the group that received the antidote, intravenous injection of 5 g of hydroxocobalamin provoked an abrupt increase in blood pressure and blood flow; PEA was prevented in all instances. However, we could not find any evidence for a recovery in oxidative metabolism in the group receiving hydroxocobalamin, as blood lactate remained elevated and even continued to rise after 1 h, despite restored hemodynamics. This, along with an unaltered recovery of H2S kinetics, suggests that hydroxocobalamin did not act through a mechanism of H2S trapping. In this sheep model, there was a high risk for cardiac arrest, by PEA, persisting up to 10 min after H2S exposure. Very high dose of hydroxocobalamin (5 g), injected very early after the cessation of H2S exposure, improved cardiac contractility and prevented PEA.

  1. Hydrogen sulfide induces calcium waves in astrocytes.

    PubMed

    Nagai, Yasuo; Tsugane, Mamiko; Oka, Jun-Ichiro; Kimura, Hideo

    2004-03-01

    Hydrogen sulfide (H2S) modifies hippocampal long-term potentiation (LTP) and functions as a neuromodulator. Here, we show that H2S increases intracellular Ca2+ and induces Ca2+ waves in primary cultures of astrocytes as well as hippocampal slices. H2S increases the influx of Ca2+ and to a lesser extent causes the release from intracellular Ca2+ stores. Ca2+ waves induced by neuronal excitation as well as responses to exogenously applied H2S are potently blocked by La3+ and Gd3+, inhibitors of Ca2+ channels. These observations suggest that H2S induces Ca2+ waves that propagate to neighboring astrocytes.

  2. Microaeration reduces hydrogen sulfide in biogas

    USDA-ARS?s Scientific Manuscript database

    Although there are a variety of biological and chemical treatments for removal of hydrogen sulfide (H2S) from biogas, all require some level of chemical or water inputs and maintenance. In practice, managing biogas H2S remains a significant challenge for agricultural digesters where labor and opera...

  3. Photoinduced oxidation of H2S species: A sink for sulfide in seawater

    NASA Astrophysics Data System (ADS)

    Pos, Willer H.; Milne, Peter J.; Riemer, Daniel D.; Zika, Rod G.

    1997-06-01

    Photokinetic studies demonstrate that sulfide is consumed in seawater upon light exposure. The half-life (t1/2) of sulfide (10 μM) added to Biscayne Bay water and Gulf Stream water are 49(±15) and 147(±10) min, respectively. Both UV and visible radiation were shown to accelerate the photodecomposition of sulfide. However, due to a higher amount of radiation in the visible range reaching the sea surface, we predict that this portion of the light spectrum will be most important in inducing photoreaction of sufide in seawater. This as yet unaccounted sink of sulfide in seawater could be responsible for the sulfide daytime low and nighttime high concentration values observed by several investigators. This finding further unbalances the sulfide budget and reinforces the need for systematic research on the role of photochemical processes on sulfur species in seawater.

  4. [Hydrogen sulfide and penile erection].

    PubMed

    Huang, Yi-Ming; Cheng, Yong; Jiang, Rui

    2012-09-01

    Hydrogen sulfide (H2S) is the third type of active endogenous gaseous signal molecule following nitric oxide (NO) and carbon monoxide (CO). In mammalians, H2S is mainly synthesized by two proteases, cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE). H2S plays an essential function of physiological regulation in vivo, and promotes penile erection by acting on the ATP-sensitive potassium channels to relax the vascular smooth muscle as well as by the synergistic effect with testosterone and NO to relax the corpus cavernosum smooth muscle (CCSM). At present, the selective phosphodiesterase type 5 (PDE5) inhibitor is mainly used for the treatment of erectile dysfunction (ED), but some ED patients fail to respond. Therefore, further studies on the mechanism of H2S regulating penile erection may provide a new way for the management of erectile dysfunction.

  5. Hydrogen Sulfide as a Gasotransmitter

    PubMed Central

    Gadalla, Moataz M.; Snyder, Solomon H.

    2010-01-01

    Nitric oxide (NO) and carbon monoxide (CO) are well established as messenger molecules throughout the body, gasotransmitters, based on striking alterations in mice lacking the appropriate biosynthetic enzymes. Hydrogen sulfide (H2S) is even more chemically reactive, but till recently there was little definitive evidence for its physiologic formation. Cystathionine β-synthase (CBS, EC 4.2.1.22), and Cystathionine γ-lyase (CSE; EC 4.4.1.1), also known as cytathionase, can generate H2S from cyst(e)ine. Very recent studies with mice lacking these enzymes have established that CSE is responsible for H2S formation in the periphery, while in the brain CBS is the biosynthetic enzyme. Endothelial-derived relaxing factor (EDRF) activity is reduced 80% in the mesenteric artery of mice with deletion of CSE, establishing H2S as a major physiologic EDRF. H2S appears to signal predominantly by S-sulfhydrating cysteines in its target proteins, analogous to S-nitrosylation by NO. Whereas S-nitrosylation typically inhibits enzymes, S-sulfhydration activates them. S-nitrosylation basally affects 1–2% of its target proteins, while 10–25% of H2S target proteins are S-sulfhydrated. In summary, H2S appears to be a physiologic gasotransmitter of comparable importance to NO and CO. PMID:20067586

  6. Signaling of hydrogen sulfide and polysulfides.

    PubMed

    Kimura, Hideo

    2015-02-10

    It has been almost two decades since the first demonstration of hydrogen sulfide (H2S) as a physiological mediator of cognitive function and vascular tone. H2S is physiologically important because it protects various organs from ischemia-reperfusion injury besides regulating inflammation, oxygen sensing, cell growth, and senescence. The production, metabolism, and regulation of H2S have been studied extensively. H2S modulates target proteins through sulfhydration (or sulfuration) or by the reduction of cysteine disulfide bonds. A large number of novel H2S-donating compounds are being developed owing to the therapeutic potential of H2S. Recently, polysulfides, rather than H2S, have been identified as molecules that sulfhydrate (or sulfurate) their target proteins.

  7. Hydrogen sulfide in gastrointestinal and liver physiopathology.

    PubMed

    Cipriani, Sabrina; Mencarelli, Andrea

    2011-04-01

    Hydrogen sulfide (H(2)S) is a gas that can be formed by the action of two enzymes, cystathionine gamma lyase (CSE) and cystathionine beta synthase (CBS). H(2)S has been known for hundreds of years for its poisoning effect, however the idea that H(2)S is not only a poison, but can exert a physiological role in mammalian organisms, originates from the evidence that this gaseous mediator is produced endogenously. In addition to H(2)S synthesis by gastrointestinal tissue, the intestinal mucosa, particularly in the large intestine, is regularly exposed to high concentrations of H(2)S that are generated by some species of bacteria and through the reduction of unabsorbed intestinal inorganic sulphate. This review reports on the effects of H(2)S in the gastrointestinal tract and liver and provides information on the therapeutic applications of H(2)S-donating drugs.

  8. Measurements of dimethyl sulfide and H2S over the western North Atlantic and the tropical Atlantic

    NASA Astrophysics Data System (ADS)

    Andreae, T. W.; Andreae, M. O.; Bingemer, H. G.; Leck, C.

    1993-12-01

    Airborne measurements of DMS and H2S were made off the east coast of the United States and over the tropical Atlantic off Brazil. Samples were collected through a fluorinated ethylene propylene Teflon inlet manifold. Dimethyl sulfide (DMS) was preconcentrated onto gold wool and analyzed by gas chromatography/flame photometric detection. H2S was collected on AgNO3-impregnated filters and determined by fluorescence quenching. Use of a new scrubber material (cotton) to remove negative interference on DMS measurements was investigated. Comparison with a Na2CO3/Anakrom scrubber gave good overall agreement. Only under extreme conditions, e.g., on flight 9 (continental air mass, low humidity, high O3, and low DMS values) did Na2CO3 show noticeable loss of DMS compared to cotton. On most flights, especially in marine air masses with high humidity and relatively low O3, the results from both scrubbers agreed well with each other and with other instruments used during the intercalibration. Off the U.S. East Coast, DMS levels showed strong dependence on air mass origin with high values (up to 83 ppt) in marine tropical air masses and low values (10-20 ppt) in continental and polar air. Over the tropical Atlantic, DMS ranged over 20-100 ppt in the mixed layer. Nighttime values were a factor of 1.6-2.3 higher than daytime levels. DMS decreased with altitude to <1 ppt at 4000 m. H2S in the mixed layer off the U.S. East Coast ranged from 10 to 200 ppt. Significant influence from terrestrial and pollution sources was evident. H2S in air masses originating over the eastern seaboard was much higher than in continental polar air or over the remote tropical continents. In contrast, over the tropical Atlantic, concentrations were very low (5-10 ppt), typical of truly marine air. Night/day ratios were about 1.4. No significant geographical variability was seen in H2S levels over the tropical Atlantic. The correlation of atmospheric 222Rn and H2S was significant, with both being higher

  9. Estimation of bacterial hydrogen sulfide production in vitro

    PubMed Central

    Basic, Amina; Blomqvist, Susanne; Carlén, Anette; Dahlén, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  10. Hydrogen sulfide: neurochemistry and neurobiology.

    PubMed

    Qu, K; Lee, S W; Bian, J S; Low, C-M; Wong, P T-H

    2008-01-01

    Current evidence suggests that hydrogen sulfide (H2S) plays an important role in brain functions, probably acting as a neuromodulator as well as an intracellular messenger. In the mammalian CNS, H2S is formed from the amino acid cysteine by the action of cystathionine beta-synthase (CBS) with serine (Ser) as the by-product. As CBS is a calcium and calmodulin dependent enzyme, the biosynthesis of H2S should be acutely controlled by the intracellular concentration of calcium. In addition, it is also regulated by S-adenosylmethionine which acts as an allosteric activator of CBS. H2S, as a sulfhydryl compound, has similar reducing properties as glutathione. In neurons, H2S stimulates the production of cAMP probably by direct activation of adenylyl cyclase and thus activate cAMP-dependent processes. In astrocytes, H2S increases intracellular calcium to an extent capable of inducing and propagating a "calcium wave", which is a form of calcium signaling among these cells. Possible physiological functions of H2S include potentiating long-term potentials through activation of the NMDA receptors, regulating the redox status, maintaining the excitatory/inhibitory balance in neurotransmission, and inhibiting oxidative damage through scavenging free radicals and reactive species. H2S is also involved in CNS pathologies such as stroke and Alzheimer's disease. In stroke, H2S appears to act as a mediator of ischemic injuries and thus inhibition of its production has been suggested to be a potential treatment approach in stroke therapy.

  11. Measurements of dimethyl sulfide and H2S over the western North Atlantic and the tropical Atlantic

    NASA Technical Reports Server (NTRS)

    Andreae, T. W.; Andreae, M. O.; Bingemer, H. G.; Leck, C.

    1993-01-01

    Airborne measurements of DMS and H2S were made off the east coast of the United States and over the tropical Atlantic off Brazil. Samples were collected through a fluorinated ethylene propylene Teflon inlet manifold. Dimethyl sulfide (DMS) was preconcentrated onto gold wool and analyzed by gas chromatography/flame photometric detection. H2S was collected on AgNO3-impregnated filters and determined by fluorescence quenching. Use of a new scrubber material (cotton) to remove negative interference on DMS measurements was investigated. Comparison with a Na2CO3/Anakrom scrubber gave good overall agreement. Only under extreme conditions, e.g., on flight 9 (continental air mass, low humidity, high O3, and low DMS values) did Na2CO3 show noticeable loss of DMS compared to cotton. On most flights, especially in marine air masses with high humidity and relatively low O3, the results from both scrubbers agreed well with each other and with other instruments used during the intercalibration. Off the U.S. East Coast, DMS levels showed strong dependence on air mass origin with high values (up to 83 ppt) in marine tropical air masses and low values (10-20 ppt) in continental and polar air. Over the tropical Atlantic, DMS ranged over 20-100 ppt in the mixed layer. Nighttime values were a factor of 1.6-2.3 higher than daytime levels. DMS decreased with altitude to less than 1 ppt at 4000 m. H2S in the mixed layer off the U.S. East Coast ranged from 10 to 200 ppt. Significant influence from terrestrial and pollution sources was evident. H2S in air masses originating over the eastern seaboard was much higher than in continental polar air or over the remote tropical continents. In contrast, over the tropical Atlantic, concentrations were very low (5-10 ppt), typical of truly marine air. Night/day ratios were about 1.4. No significant geographical variability was seen in H2S levels over the tropical Atlantic. The correlation of atmospheric Rn-222 and H2S was significant, with both

  12. Measurements of dimethyl sulfide and H2S over the western North Atlantic and the tropical Atlantic

    NASA Technical Reports Server (NTRS)

    Andreae, T. W.; Andreae, M. O.; Bingemer, H. G.; Leck, C.

    1993-01-01

    Airborne measurements of DMS and H2S were made off the east coast of the United States and over the tropical Atlantic off Brazil. Samples were collected through a fluorinated ethylene propylene Teflon inlet manifold. Dimethyl sulfide (DMS) was preconcentrated onto gold wool and analyzed by gas chromatography/flame photometric detection. H2S was collected on AgNO3-impregnated filters and determined by fluorescence quenching. Use of a new scrubber material (cotton) to remove negative interference on DMS measurements was investigated. Comparison with a Na2CO3/Anakrom scrubber gave good overall agreement. Only under extreme conditions, e.g., on flight 9 (continental air mass, low humidity, high O3, and low DMS values) did Na2CO3 show noticeable loss of DMS compared to cotton. On most flights, especially in marine air masses with high humidity and relatively low O3, the results from both scrubbers agreed well with each other and with other instruments used during the intercalibration. Off the U.S. East Coast, DMS levels showed strong dependence on air mass origin with high values (up to 83 ppt) in marine tropical air masses and low values (10-20 ppt) in continental and polar air. Over the tropical Atlantic, DMS ranged over 20-100 ppt in the mixed layer. Nighttime values were a factor of 1.6-2.3 higher than daytime levels. DMS decreased with altitude to less than 1 ppt at 4000 m. H2S in the mixed layer off the U.S. East Coast ranged from 10 to 200 ppt. Significant influence from terrestrial and pollution sources was evident. H2S in air masses originating over the eastern seaboard was much higher than in continental polar air or over the remote tropical continents. In contrast, over the tropical Atlantic, concentrations were very low (5-10 ppt), typical of truly marine air. Night/day ratios were about 1.4. No significant geographical variability was seen in H2S levels over the tropical Atlantic. The correlation of atmospheric Rn-222 and H2S was significant, with both

  13. Synthesis and characterization of new ternary transition metal sulfide anodes for H 2S-powered solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Vorontsov, V.; Luo, J. L.; Sanger, A. R.; Chuang, K. T.

    A number of ternary transition metal sulfides with general composition AB 2S 4 (where A and B are different transition metal atoms) have been prepared and investigated as potential anode catalysts for use in H 2S-powered solid oxide fuel cells (SOFCs). For the initial screening, polarization resistance of the materials was measured in a two electrode symmetrical cell at 700-850 °C. Vanadium-based materials showed the lowest polarization resistance, and so were chosen for subsequent full cell tests using the configuration [H 2S, AV 2S 4/YSZ/Pt, air] (where A = Ni, Cr, Mo). MoV 2S 4 anode had superior activity and performance in the full cell setup, consistent with results from symmetrical cell tests. Polarization curves showed MoV 2S 4 had the lowest potential drop, with up to a 200 mA cm -2 current density at 800 °C. The highest power density of ca. 275 mW cm -2 at 800 °C was obtained with a pure H 2S stream. Polarization resistance of materials was a strong function of current density, and showed a sharp change of slope attributable to a change in the rate-limiting step of the anode reaction mechanism. MoV 2S 4 was chemically stable during prolonged (10 days) exposure to H 2S at 850 °C, and fuel cell performance was stable during continuous 3-day operation at 370 mA cm -2 current density.

  14. Chemical Foundations of Hydrogen Sulfide Biology

    PubMed Central

    Li, Qian; Lancaster, Jack R.

    2013-01-01

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  15. Hydrogen sulfide in hemostasis: friend or foe?

    PubMed

    Olas, Beata

    2014-06-25

    Hydrogen sulfide (H2S) is a well known toxic gas that is synthesized from the amino acids: cysteine (Cys) and homocysteine (Hcy) by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and mercaptopyruvate sulfurtransferase (3-MST). Hydrogen sulfide, like carbon monoxide (CO) or nitric oxide (NO) is a signaling molecule in different biological systems, including the cardiovascular system. Moreover, hydrogen sulfide plays a role in the pathogenesis of various cardiovascular diseases. It modulates different elements of hemostasis (activation of blood platelet, and coagulation process) as well as proliferation and apoptosis of vascular smooth muscle cells. However, the biological role and the therapeutic potential of H2S is not clear. This review summarizes the different functions of hydrogen sulfide in hemostasis.

  16. Hydrogen sulfide in the mammalian cardiovascular system.

    PubMed

    Liu, Yi-Hong; Lu, Ming; Hu, Li-Fang; Wong, Peter T-H; Webb, George D; Bian, Jin-Song

    2012-07-01

    For more than a century, hydrogen sulfide (H(2)S) has been regarded as a toxic gas. This review surveys the growing recognition of the role of H(2)S as an endogenous signaling molecule in mammals, with emphasis on its physiological and pathological pathways in the cardiovascular system. In biological fluids, H(2)S gas is a weak acid that exists as about 15% H(2)S, 85% HS(-), and a trace of S(2-). Here, we use "H(2)S" to refer to this mixture. H(2)S has been found to influence heart contractile functions and may serve as a cardioprotectant for treating ischemic heart diseases and heart failure. Alterations of the endogenous H(2)S level have been found in animal models with various pathological conditions such as myocardial ischemia, spontaneous hypertension, and hypoxic pulmonary hypertension. In the vascular system, H(2)S exerts biphasic regulation of a vascular tone with varying effects based on its concentration and in the presence of nitric oxide. Over the past decade, several H(2)S-releasing compounds (NaHS, Na(2)S, GYY4137, etc.) have been utilized to test the effect of exogenous H(2)S under different physiological and pathological situations in vivo and in vitro. H(2)S has been found to promote angiogenesis and to protect against atherosclerosis and hypertension, while excess H(2)S may promote inflammation in septic or hemorrhagic shock. H(2)S-releasing compounds and inhibitors of H(2)S synthesis hold promise in alleviating specific disease conditions. This comprehensive review covers in detail the effects of H(2)S on the cardiovascular system, especially in disease situations, and also the various underlying mechanisms.

  17. Hydrogen sulfide and nervous system regulation.

    PubMed

    Zhou, Cheng-Fang; Tang, Xiao-Qing

    2011-11-01

    This review discusses the current status and progress in studies on the roles of hydrogen sulfide (H(2)S) in regulation of neurotoxicity, neuroprotection, and neuromodulator, as well as its therapeutic potential for neurodegenerative disorders. The data used in this review were mainly from Medline and PubMed published in English from 2001 to August 2011. The search terms were "hydrogen sulfide", "neuron", and "neurodegenerative disorders". Articles regarding the regulation of neuronal function, the protection against neuronal damage and neurological diseases, and their possible cellular and molecular mechanisms associated with H(2)S were selected. The inhibited generation of endogenous H(2)S is implicated in 1-methy-4-phenylpyridinium ion, 6-OHDA, and homocysteine-triggered neurotoxicity. H(2)S elicits neuroprotection in Alzheimer's disease and Parkinson's disease models as well as protecting neurons against oxidative stress, ischemia, and hypoxia-induced neuronal death. H(2)S offers anti-oxidant, anti-inflammatory and anti-apoptotic effects, as well as activates ATP-sensitive potassium channels and cystic fibrosis transmembrane conductance regulator Cl- channels. H(2)S regulates the long-term potentiation (LTP) and GABAB receptors in the hippocampus, as well as intracellular calcium and pH homeostasis in neurons and glia cells. These articles suggest that endogenous H(2)S may regulate the toxicity of neurotoxin. H(2)S not only acts as a neuroprotectant but also serves as a novel neuromodulator.

  18. Hydrogen Sulfide Signaling in the Gastrointestinal Tract

    PubMed Central

    2014-01-01

    Abstract Significance: The current literature regarding the effects of the gaseous signal molecule hydrogen sulfide (H2S) in the gastrointestinal system is reviewed. Bacterial, host and pharmaceutical-derived H2S are all considered and presented according to the physiological or pathophysiological effects of the gaseous signal molecule. These subjects include the toxicology of intestinal H2S with emphasis on bacterial-derived H2S, especially from sulfate-reducing bacteria, the role of endogenous and exogenous H2S in intestinal inflammation, and the roles of H2S in gastrointestinal motility, secretion and nociception. Recent Advances: While its pro- and anti-inflammatory, smooth muscle relaxant, prosecretory, and pro- and antinociceptive actions continue to remain the major effects of H2S in this system; recent findings have expanded the potential molecular targets for H2S in the gastrointestinal tract. Critical Issues: Numerous discrepancies remain in the literature, and definitive molecular targets in this system have not been supported by the use of competitive antagonism. Future Directions: Future work will hopefully resolve discrepancies in the literature and identify molecular targets and mechanisms of action for H2S. It is clear from the current literature that the long-appreciated relationship between H2S and the gastrointestinal tract continues to be strong as we endeavor to unravel its mysteries. Antioxid. Redox Signal. 20, 818–830. PMID:23582008

  19. Hydrogen Sulfide in Biochemistry and Medicine

    PubMed Central

    Predmore, Benjamin Lee; Lefer, David Joseph

    2012-01-01

    Abstract Significance: An abundance of experimental evidence suggests that hydrogen sulfide (H2S) plays a prominent role in physiology and pathophysiology. Many targets exist for H2S therapy. The molecular targets of H2S include proteins, enzymes, transcription factors, and membrane ion channels. Recent Advances: Novel H2S precursors are being synthesized and discovered that are capable of releasing H2S in a slow and sustained manner. This presents a novel and advantageous approach to H2S therapy for treatment of chronic conditions associated with a decline in endogenous H2S, such as diabetes and cardiovascular disease. Critical Issues: While H2S is cytoprotective at physiological concentrations, it is not universally cytoprotective, as it appears to have pro-apoptotic actions in cancer cells and is well known to be toxic at supraphysiological concentrations. Many of the pleiotropic effects of H2S on health are associated with the inhibition of inflammation and upregulation of prosurvival pathways. The powerful anti-inflammatory, cytoprotective, immunomodulating, and trophic effects of H2S on the vast majority of normal cells seem to be mediated mainly by its actions as an extremely versatile direct and indirect antioxidant and free radical scavenger. While the overall effects of H2S on transformed (i.e., malignant) cells can be characterized as pro-oxidant and pro-apoptotic, they contrast sharply with the cytoprotective effects on most normal cells. Future Directions: H2S has become a molecule of great interest, and several slow-releasing H2S prodrugs are currently under development. We believe that additional agents regulating H2S bioavailability will be developed during the next 10 years. Antioxid. Redox Signal. 17, 119–140. PMID:22432697

  20. Hydrogen sulfide and polysulfides as signaling molecules

    PubMed Central

    KIMURA, Hideo

    2015-01-01

    Hydrogen sulfide (H2S) is a familiar toxic gas that smells of rotten eggs. After the identification of endogenous H2S in the mammalian brain two decades ago, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress, angiogenesis, anti-inflammation, and oxygen sensing. Enzymes that produce H2S, such as cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase have been studied intensively and well characterized. Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors, and tumor suppressors with greater potency than that of H2S. This article focuses on our contribution to the discovery of these molecules and their metabolic pathways and mechanisms of action. PMID:25864468

  1. Hydrogen Sulfide and Inflammatory Joint Diseases.

    PubMed

    Burguera, Elena Fernandez; Meijide-Failde, Rosa; Blanco, Francisco J

    2016-08-29

    Rheumatoid arthritis (RA) and osteoarthritis (OA) are widespread rheumatic diseases characterized by persistent inflammation and joint destruction. Hydrogen sulfide (H2S) is an endogenous gas with important physiologic functions in the brain, vasculature and other organs. Recent studies have found H2S to be a mediator in inflammatory joint diseases. H2S exhibited anti-inflammatory, anti-catabolic and/or anti-oxidant effects in rodent models of acute arthritis and in in vitro models using human synoviocytes and articular chondrocytes from RA and OA tissues. These findings suggest that exogenous supplementation of H2S may provide a viable therapeutic option for these diseases. The earliest studies used fast-dissolving salts, such as NaSH, but GYY4137, which produces H2S more physiologically, shortly appeared. More recently still, new H2S-forming compounds that target mitochondria have been synthesized. These compounds open exciting opportunities for investigating the role of H2S in cell bioenergetics, typically altered in arthritides. Positive results have been also obtained when H2S is administered as a sulphurous water bath, an option meriting further study. This review summarizes the recent literature concerning H2S and inflammatory joint diseases, highlighting relevant developments.

  2. A rapid, non-destructive methodology to monitor activity of sulfide-induced corrosion of concrete based on H2S uptake rate.

    PubMed

    Sun, Xiaoyan; Jiang, Guangming; Bond, Philip L; Wells, Tony; Keller, Jurg

    2014-08-01

    Many existing methods to monitor the corrosion of concrete in sewers are either very slow or destructive measurements. To overcome these limitations, a rapid, non-invasive methodology was developed to monitor the sulfide-induced corrosion process on concrete through the measurement of the H2S uptake rates of concrete at various corrosion stages. The H2S uptake rate for a concrete coupon was determined by measuring the gaseous H2S concentrations over time in a temperature- and humidity-controlled gas-tight reactor. The reliability of this method was evaluated by carrying out repeated tests on different concrete coupons previously exposed to 50 ppm of H2S, at 30 °C and 100% relative humidity for over 32 months. The H2S uptake measurements showed good reproducibility. It was also shown that a severely corroded coupon exhibited higher sulfide uptake rates than a less corroded coupon. This could be explained by the corrosion layer in the more corroded coupon having a higher biological sulfide oxidation activity than the less corroded coupon. Additionally, temperature changes had a stronger effect on the uptake rate of the heavily corroded coupon compared to the less corroded coupon. A corrosion rate of 8.9 ± 0.5 mm/year, estimated from the H2S uptake results, agreed well with the corrosion rate observed in real sewers under similar conditions. The method could be applied to investigate important factors affecting sulfide-induced concrete corrosion, particularly temperature, fluctuating gaseous H2S concentrations, oxygen concentrations, surface pH and relative humidity.

  3. Identification of Hydrogen Disulfanes and Hydrogen Trisulfanes in H2S Bottle, in Flint, and in Dry Mineral White Wine.

    PubMed

    Starkenmann, Christian; Chappuis, Charles Jean-Francois; Niclass, Yvan; Deneulin, Pascale

    2016-11-30

    Through the accidental contamination of a gas cylinder of H2S, the importance of polysulfanes for flint, gun powder, and match odors was discovered. The hydrogen disulfane was prepared from disulfanediylbis[methyl(diphenyl)silane], and its odor descriptor was evaluated in the gas phase from a gas chromatograph coupled to an olfaction port. The occurrence of this compound in flint and pebbles was confirmed by analyses after derivatization with pentafluorobromobenzene. The occurrence of this sulfane was also confirmed in two dry white Swiss Chasselas wines, sorted by a large-scale sensory analysis from 80 bottles and evaluated by 62 wine professionals. The occurrence of disulfane was confirmed for the two wines described as the most mineral. Polysulfane comprises a class of compounds contributing to the flint odor and that may contribute to the wine mineral odor descriptor. Due to the high volatility and instability pure HSSH was not isolated but kept in solution and its odor profile was described by gas chromatography coupled to an olfaction port as flint, matches, and fireworks with a higher odor intensity compared to H2S.

  4. The role of hydrogen sulfide in burns.

    PubMed

    Akter, Farhana

    2016-05-01

    Hydrogen sulfide is a novel gasotransmitter that has been shown to play a major role in regulating vascular tone. However, the role of hydrogen sulfide in inflammation, sepsis and burns has only recently been studied. In animal studies, hydrogen sulfide has been shown to play a role in both promoting and inhibiting inflammation. Understanding the role of H2S in sepsis and shock is particularly important due to the high mortality associated with both conditions. In animal sepsis models, hydrogen sulfide appears to increase survival. Severe burns are associated with an inflammatory response that causes increased permeability and edema. Currently, there are few studies that have examined the exact role of hydrogen sulfide in burns. However, the role of hydrogen sulfide in inflammation enables us to hypothesize its role in burns. This review highlights the role of hydrogen sulfide in the mechanisms of action underlying inflammation, wound healing and sepsis as well as examining the potential role of hydrogen sulfide in burns. The authors of this article hope that this review will stimulate research to discover the exact role of this fascinating molecule in burns.

  5. Biological chemistry of hydrogen sulfide and persulfides.

    PubMed

    Cuevasanta, Ernesto; Möller, Matías N; Alvarez, Beatriz

    2017-03-01

    Hydrogen sulfide (H2S) has been traditionally considered to be a toxic molecule for mammals. However, it can be formed endogenously and exert physiological effects with potential health benefits. H2S can partition two-fold in biological membranes and traverse them rapidly, diffusing between compartments. H2S reactivity has similarities to that of thiols, although it is less nucleophilic than thiols and it can form different products. H2S can react with oxidants derived from the partial reduction of oxygen, but direct scavenging is unlikely to explain H2S protective actions. Important effects are exerted on mitochondria including the stimulation or the inhibition of the electron transport chain. Possible mechanisms for unleashing biological consequences are the reactions with metal centers and with thiol oxidation products. The reactions of H2S with disulfides (RSSR) and sulfenic acids (RSOH) lead to the formation of persulfides (RSSH). Persulfides have enhanced nucleophilicity with respect to the corresponding thiol, consistent with the alpha effect. Besides, the inner and outer sulfurs can both act as electrophiles. In this review, we describe the reactions of H2S with oxidized thiol products and the properties of the persulfides formed in the context of the chemical biology of H2S.

  6. Signaling Molecules: Hydrogen Sulfide and Polysulfide

    PubMed Central

    2015-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a signaling molecule as well as a cytoprotectant. It modulates neurotransmission, regulates vascular tone, and protects various tissues and organs, including neurons, the heart, and kidneys, from oxidative stress and ischemia-reperfusion injury. H2S is produced from l-cysteine by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase. Recent Advances: In addition to these enzymes, we recently identified a novel pathway to produce H2S from d-cysteine, which involves d-amino acid oxidase (DAO) along with 3MST. These enzymes are localized in the cytoplasm, mitochondria, and peroxisomes. However, some enzymes translocate to organelles under specific conditions. Moreover, H2S-derived potential signaling molecules such as polysulfides and HSNO have been identified. Critical Issues: The physiological stimulations, which trigger the production of H2S and its derivatives and maintain their local levels, remain unclear. Future Directions: Understanding the regulation of the H2S production and H2S-derived signaling molecules and the specific stimuli that induce their release will provide new insights into the biology of H2S and therapeutic development in diseases involving these substances. Antioxid. Redox Signal. 22, 362–376. PMID:24800864

  7. Hydrogen sulfide as a vasculoprotective factor

    PubMed Central

    2013-01-01

    Hydrogen sulfide is a novel mediator with the unique properties of a gasotransmitter and many and varied physiological effects. Included in these effects are a number of cardiovascular effects that are proving beneficial to vascular health. Specifically, H2S can elicit vasorelaxation, prevention of inflammation and leukocyte adhesion, anti-proliferative effects and anti-thrombotic effects. Additionally, H2S is a chemical reductant and nucleophile that is capable of inhibiting the production of reactive oxygen species, scavenging and neutralising reactive oxygen species and boosting the efficacy of endogenous anti-oxidant molecules. These result in resistance to oxidative stress, protection of vascular endothelial function and maintenance of blood flow and organ perfusion. H2S has been shown to be protective in hypertension, atherosclerosis and under conditions of vascular oxidative stress, and deficiency of endogenous H2S production is linked to cardiovascular disease states. Taken together, these effects suggest that H2S has a physiological role as a vasculoprotective factor and that exogenous H2S donors may be useful therapeutic agents. This review article will discuss the vascular effects and anti-oxidant properties of H2S as well as examine the protective role of H2S in some important vascular disease states. PMID:23628084

  8. H2S regulation of nitric oxide metabolism

    PubMed Central

    Kolluru, Gopi K.; Yuan, Shuai; Shen, Xinggui; Kevil, Christopher G.

    2015-01-01

    Nitric oxide (NO) and hydrogen sulfide (H2S) are two major gaseous signaling molecules that regulate diverse physiological functions. Recent publications indicate the regulatory role of H2S on NO metabolism. In this chapter, we discuss the latest findings on H2S-NO interactions through formation of novel chemical derivatives, and experimental approaches to study these adducts. This chapter also addresses potential H2S interference on various NO detection techniques, along with precautions for analyzing biological samples from various sources. This information will facilitate critical evaluation and clearer insight into H2S regulation of NO signaling and its influence on various physiological functions. PMID:25725527

  9. Hydrogen Sulfide Inhibits Amyloid Formation

    PubMed Central

    2015-01-01

    Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer’s disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL). HEWL forms typical β-sheet rich fibrils during the course of 70 min at low pH and high temperatures. The addition of H2S completely inhibits the formation of β-sheet and amyloid fibrils, as revealed by deep UV resonance Raman (DUVRR) spectroscopy and ThT fluorescence. Nonresonance Raman spectroscopy shows that disulfide bonds undergo significant rearrangements in the presence of H2S. Raman bands corresponding to disulfide (RSSR) vibrational modes in the 550–500 cm–1 spectral range decrease in intensity and are accompanied by the appearance of a new 490 cm–1 band assigned to the trisulfide group (RSSSR) based on the comparison with model compounds. The formation of RSSSR was proven further using a reaction with TCEP reduction agent and LC-MS analysis of the products. Intrinsic tryptophan fluorescence study shows a strong denaturation of HEWL containing trisulfide bonds. The presented evidence indicates that H2S causes the formation of trisulfide bridges, which destabilizes HEWL structure, preventing protein fibrillation. As a result, small spherical aggregates of unordered protein form, which exhibit no cytotoxicity by contrast with HEWL fibrils. PMID:25545790

  10. Mitochondrial Sulfide Quinone Oxidoreductase Prevents Activation of the Unfolded Protein Response in Hydrogen Sulfide*

    PubMed Central

    Horsman, Joseph W.

    2016-01-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous molecule with important roles in cellular signaling. In mammals, exogenous H2S improves survival of ischemia/reperfusion. We have previously shown that exposure to H2S increases the lifespan and thermotolerance in Caenorhabditis elegans, and improves protein homeostasis in low oxygen. The mitochondrial SQRD-1 (sulfide quinone oxidoreductase) protein is a highly conserved enzyme involved in H2S metabolism. SQRD-1 is generally considered important to detoxify H2S. Here, we show that SQRD-1 is also required to maintain protein translation in H2S. In sqrd-1 mutant animals, exposure to H2S leads to phosphorylation of eIF2α and inhibition of protein synthesis. In contrast, global protein translation is not altered in wild-type animals exposed to lethally high H2S or in hif-1(ia04) mutants that die when exposed to low H2S. We demonstrate that both gcn-2 and pek-1 kinases are involved in the H2S-induced phosphorylation of eIF2α. Both ER and mitochondrial stress responses are activated in sqrd-1 mutant animals exposed to H2S, but not in wild-type animals. We speculate that SQRD-1 activity in H2S may coordinate proteostasis responses in multiple cellular compartments. PMID:26677221

  11. The liver as a central regulator of hydrogen sulfide.

    PubMed

    Norris, Eric J; Culberson, Catherine R; Narasimhan, Sriram; Clemens, Mark G

    2011-09-01

    The liver is likely exposed to high levels of hydrogen sulfide (H2S) from endogenous hepatic synthesis and exogenous sources from the gastrointestinal tract. Little is known about the consequence of H2S exposure on the liver or hepatic regulation of H2S levels. We hypothesized that the liver has a high capacity to metabolize H2S and that H2S oxidation is decreased during sepsis, a condition in which hepatic O2 is limited and H2S synthesis is increased. Using a nonrecirculating isolated and perfused liver system, we demonstrated rapid hepatic H2S metabolism up to an infusion concentration of 200' μM H2S. Hydrogen sulfide metabolism was associated with an increase in O2 consumption from a baseline 96.7 ± 7.6 μmol O2/min/kg to 109 ± 7.4 μmol O2/min/kg at an infusion concentration of 150 μM H2S (P < 0.001). Removal of O2 from the perfusate decreased H2S clearance from a maximal 97% to only 23%. Livers isolated from rats subjected to cecal ligation and puncture (CLP) did not differ significantly from control livers in their capacity to metabolize H2S, suggesting that H2S oxidation remains a priority during sepsis. To test whether H2S induces O2 consumption in vivo, intravital microscopy was utilized to monitor the oxygen content in the hepatic microenvironment. Infusion of H2S increased the NADH/NAD+ ratio (645 gray-scale-unit increase, P = 0.035) and decreased hepatic O2 availability visualized with Ru(Phen)3(2+) (439 gray-scale-unit increase, P = 0.040). We conclude that the liver has a high hepatic capacity for H2S metabolism. Moreover, H2S oxidation consumes available oxygen and may exacerbate the tissue hypoxia associated with sepsis.

  12. Oxidation of H2S in mammalian cells and mitochondria.

    PubMed

    Abou-Hamdan, Abbas; Guedouari-Bounihi, Hala; Lenoir, Véronique; Andriamihaja, Mireille; Blachier, François; Bouillaud, Frédéric

    2015-01-01

    Hydrogen sulfide (H2S) is the third gasotransmitter described in mammals. These gasotransmitters (H2S, CO, and NO) are small molecules able to diffuse freely across membranes and thus susceptible to reach easily intracellular targets, one of which is the respiratory enzyme cytochrome oxidase subject to complete inhibition by low micromolar concentrations of these gases. However in contrast to NO or CO, H2S can be metabolized by a sulfide quinone reductase feeding the mitochondrial respiratory chain with the hydrogen atoms of sulfide. Sulfide is thus a two-sided molecule: substrate or poison according to the concentration. The aim of this chapter is to present a mean to monitor sulfide oxidation by isolated mitochondria or cells and to summarize how the properties of this amazing couple (mitochondria and sulfide) translate into practical and conceptual consequences.

  13. Organelle-Targeted H2S Probes Enable Visualization of the Subcellular Distribution of H2S Donors.

    PubMed

    Montoya, Leticia A; Pluth, Michael D

    2016-06-07

    Hydrogen sulfide (H2S) is an essential biological signaling molecule in diverse biological regulatory pathways. To provide new chemical tools for H2S imaging, we report here a fluorescent H2S detection platform (HSN2-BG) that is compatible with subcellular localization SNAP-tag fusion protein methodologies and use appropriate fusion protein constructs to demonstrate mitochondrial and lysosomal localization. We also demonstrate the efficacy of this detection platform to image endogenous H2S in Chinese hamster ovary (CHO) cells and use the developed constructs to report on the subcellular H2S distributions provided by common H2S donor molecules AP39, ADT-OH, GYY4137, and diallyltrisulfide (DATS). The developed constructs provide a platform poised to provide new insights into the subcellular distribution of common H2S donors and a useful tool for investigating H2S biochemistry.

  14. Detection of thiol modifications by hydrogen sulfide.

    PubMed

    Williams, E; Pead, S; Whiteman, M; Wood, M E; Wilson, I D; Ladomery, M R; Teklic, T; Lisjak, M; Hancock, J T

    2015-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in both animals and plants. Many physiological events, including responses to stress, have been suggested to involve H2S, at least in part. On the other hand, numerous responses have been reported following treatment with H2S, including changes in the levels of antioxidants and the activities of transcription factors. Therefore, it is important to understand and unravel the events that are taking place downstream of H2S in signaling pathways. H2S is known to interact with other reactive signaling molecules such as reactive oxygen species (ROS) and nitric oxide (NO). One of the mechanisms by which ROS and NO have effects in a cell is the modification of thiol groups on proteins, by oxidation or S-nitrosylation, respectively. Recently, it has been reported that H2S can also modify thiols. Here we report a method for the determination of thiol modifications on proteins following the treatment with biological samples with H2S donors. Here, the nematode Caenorhabditis elegans is used as a model system but this method can be used for samples from other animals or plants. © 2015 Elsevier Inc. All rights reserved.

  15. Interstellar hydrogen sulfide.

    NASA Technical Reports Server (NTRS)

    Thaddeus, P.; Kutner, M. L.; Penzias, A. A.; Wilson, R. W.; Jefferts, K. B.

    1972-01-01

    Hydrogen sulfide has been detected in seven Galactic sources by observation of a single line corresponding to the rotational transition from the 1(sub 10) to the 1(sub 01) levels at 168.7 GHz. The observations show that hydrogen sulfide is only a moderately common interstellar molecule comparable in abundance to H2CO and CS, but somewhat less abundant than HCN and much less abundant than CO.

  16. Interstellar hydrogen sulfide.

    NASA Technical Reports Server (NTRS)

    Thaddeus, P.; Kutner, M. L.; Penzias, A. A.; Wilson, R. W.; Jefferts, K. B.

    1972-01-01

    Hydrogen sulfide has been detected in seven Galactic sources by observation of a single line corresponding to the rotational transition from the 1(sub 10) to the 1(sub 01) levels at 168.7 GHz. The observations show that hydrogen sulfide is only a moderately common interstellar molecule comparable in abundance to H2CO and CS, but somewhat less abundant than HCN and much less abundant than CO.

  17. Protective Effects of Hydrogen Sulfide in the Ageing Kidney

    PubMed Central

    Hou, Cui-Lan; Wang, Ming-Jie; Sun, Chen; Huang, Yong; Jin, Sheng; Mu, Xue-Pan; Chen, Ying

    2016-01-01

    Aims. The study aimed to examine whether hydrogen sulfide (H2S) generation changed in the kidney of the ageing mouse and its relationship with impaired kidney function. Results. H2S levels in the plasma, urine, and kidney decreased significantly in ageing mice. The expression of two known H2S-producing enzymes in kidney, cystathionine γ-lyase (CSE) and cystathionine-β-synthase (CBS), decreased significantly during ageing. Chronic H2S donor (NaHS, 50 μmol/kg/day, 10 weeks) treatment could alleviate oxidative stress levels and renal tubular interstitial collagen deposition. These protective effects may relate to transcription factor Nrf2 activation and antioxidant proteins such as HO-1, SIRT1, SOD1, and SOD2 expression upregulation in the ageing kidney after NaHS treatment. Furthermore, the expression of H2S-producing enzymes changed with exogenous H2S administration and contributed to elevated H2S levels in the ageing kidney. Conclusions. Endogenous hydrogen sulfide production in the ageing kidney is insufficient. Exogenous H2S can partially rescue ageing-related kidney dysfunction by reducing oxidative stress, decreasing collagen deposition, and enhancing Nrf2 nuclear translocation. Recovery of endogenous hydrogen sulfide production may also contribute to the beneficial effects of NaHS treatment. PMID:27882191

  18. Protective Effects of Hydrogen Sulfide in the Ageing Kidney.

    PubMed

    Hou, Cui-Lan; Wang, Ming-Jie; Sun, Chen; Huang, Yong; Jin, Sheng; Mu, Xue-Pan; Chen, Ying; Zhu, Yi-Chun

    2016-01-01

    Aims. The study aimed to examine whether hydrogen sulfide (H2S) generation changed in the kidney of the ageing mouse and its relationship with impaired kidney function. Results. H2S levels in the plasma, urine, and kidney decreased significantly in ageing mice. The expression of two known H2S-producing enzymes in kidney, cystathionine γ-lyase (CSE) and cystathionine-β-synthase (CBS), decreased significantly during ageing. Chronic H2S donor (NaHS, 50 μmol/kg/day, 10 weeks) treatment could alleviate oxidative stress levels and renal tubular interstitial collagen deposition. These protective effects may relate to transcription factor Nrf2 activation and antioxidant proteins such as HO-1, SIRT1, SOD1, and SOD2 expression upregulation in the ageing kidney after NaHS treatment. Furthermore, the expression of H2S-producing enzymes changed with exogenous H2S administration and contributed to elevated H2S levels in the ageing kidney. Conclusions. Endogenous hydrogen sulfide production in the ageing kidney is insufficient. Exogenous H2S can partially rescue ageing-related kidney dysfunction by reducing oxidative stress, decreasing collagen deposition, and enhancing Nrf2 nuclear translocation. Recovery of endogenous hydrogen sulfide production may also contribute to the beneficial effects of NaHS treatment.

  19. Release and control of hydrogen sulfide during sludge thermal drying

    SciTech Connect

    Weng, Huanxin; Dai, Zhixin; Ji, Zhongqiang; Gao, Caixia; Liu, Chongxuan

    2015-04-15

    The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: 1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, 2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and 3) decreasing sludge pH increased the H2S release. Based on the findings from this study, a new system that integrates sludge drying and H2S gas treatment was developed to reduce the amount of H2S released from sludge treatments.

  20. Hydrogen Sulfide Is a Signaling Molecule and a Cytoprotectant

    PubMed Central

    Shibuya, Norihiro; Kimura, Yuka

    2012-01-01

    Abstract Significance: Accumulating evidence shows that hydrogen sulfide may function as a signaling molecule in processes such as neuromodulation in the brain and smooth muscle relaxation in the vascular system. It also has a cytoprotective effect, since it can protect neurons and cardiac muscle from oxidative stress and ischemia-reperfusion injury, respectively. Hydrogen sulfide can also modulate inflammation, insulin release, and angiogenesis. Recent Advances: The regulation of the activity of 3-mercaptopyruvate sulfur transferase (3MST) along with cysteine aminotransferase (CAT), one of the H2S producing pathways, has been demonstrated. The production of H2S by the pathway, which is regulated by Ca2+ and facilitated by thioredoxin and dihydrolipoic acid, is also involved in H2S signaling as well as cytoprotection. Sulfur hydration of proteins by H2S has been proposed to modulate protein functions. H2S-sensitive fluorescent probes, which enable us to measure the localization of H2S in real time, have been developed. Critical Issues: The basal concentrations of H2S have recently been measured and found to be much lower than those initially reported. However, the concentration of H2S reached in stimulated cells, as well as the regulation of H2S producing enzymes is not well understood. It has been proposed that some of the effects of H2S on the regulation of enzymes and receptors might be explained through the properties of sulfane sulfur (S0), another form of active sulfur. Future Directions: The determination of H2S concentrations in activated cells using new methods including H2S-sensitive fluorescent probes, as well as the investigation of the effects of H2S using specific inhibitors, may provide better understanding of the physiological function of this molecule. Clarifying mechanisms of H2S activity may also facilitate the development of new therapeutic compounds. Antioxid. Redox Signal. 17, 45–57. PMID:22229673

  1. Hydrogen sulfide and polysulfides as biological mediators.

    PubMed

    Kimura, Hideo

    2014-10-09

    Hydrogen sulfide (H2S) is recognized as a biological mediator with various roles such as neuromodulation, regulation of the vascular tone, cytoprotection, anti-inflammation, oxygen sensing, angiogenesis, and generation of mitochondrial energy. It is produced by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST). The activity of CBS is enhanced by S-adenosyl methionine (SAM) and glutathionylation, while it is inhibited by nitric oxide (NO) and carbon monoxide (CO). The activity of CSE and cysteine aminotransferase (CAT), which produces the 3MST substrate 3-mercaptopyruvate (3MP), is regulated by Ca2+. H2S is oxidized to thiosulfate in mitochondria through the sequential action of sulfide quinone oxidoreductase (SQR), sulfur dioxygenase, and rhodanese. The rates of the production and clearance of H2S determine its cellular concentration. Polysulfides (H2Sn) have been found to occur in the brain and activate transient receptor potential ankyrin 1 (TRPA1) channels, facilitate the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus, and suppress the activity of phosphatase and tensin homolog (PTEN) by sulfurating (sulfhydrating) the target cysteine residues. A cross talk between H2S and NO also plays an important role in cardioprotection as well as regulation of the vascular tone. H2S, polysulfides, and their cross talk with NO may mediate various physiological and pathophysiological responses.

  2. Hydrogen Sulfide as an Oxygen Sensor

    PubMed Central

    2015-01-01

    Abstract Significance Although oxygen (O2)-sensing cells and tissues have been known for decades, the identity of the O2-sensing mechanism has remained elusive. Evidence is accumulating that O2-dependent metabolism of hydrogen sulfide (H2S) is this enigmatic O2 sensor. Recent Advances The elucidation of biochemical pathways involved in H2S synthesis and metabolism have shown that reciprocal H2S/O2 interactions have been inexorably linked throughout eukaryotic evolution; there are multiple foci by which O2 controls H2S inactivation, and the effects of H2S on downstream signaling events are consistent with those activated by hypoxia. H2S-mediated O2 sensing has been demonstrated in a variety of O2-sensing tissues in vertebrate cardiovascular and respiratory systems, including smooth muscle in systemic and respiratory blood vessels and airways, carotid body, adrenal medulla, and other peripheral as well as central chemoreceptors. Critical Issues Information is now needed on the intracellular location and stoichometry of these signaling processes and how and which downstream effectors are activated by H2S and its metabolites. Future Directions Development of specific inhibitors of H2S metabolism and effector activation as well as cellular organelle-targeted compounds that release H2S in a time- or environmentally controlled way will not only enhance our understanding of this signaling process but also provide direction for future therapeutic applications. Antioxid. Redox Signal. 22, 377–397. “Nothing in Biology Makes Sense Except in the Light of Evolution” —Theodosius Dobzhansky (29) PMID:24801248

  3. Using hydrogen sulfide to design and develop drugs.

    PubMed

    Calderone, Vincenzo; Martelli, Alma; Testai, Lara; Citi, Valentina; Breschi, Maria C

    2016-01-01

    Hydrogen sulfide (H2S) is an endogenous gasotransmitter, involved in the regulation of several biological functions. Conversely, impaired biosynthesis of H2S is associated with important diseases. This paves the way for exciting pharmacological perspectives for drugs acting on the 'H2S system'. At the beginning of this manuscript, the authors present the biological roles and mechanisms of action of hydrogen sulfide. The authors then discuss the developments in the modulation of the H2S system via heterogeneous molecules, which behave as sources of exogenous H2S, and are promising drugs for a number of diseases. The rate of H2S generation, the physicochemical characteristics and the bioavailability greatly affect the overall pharmacological profile of each H2S-releasing compound. Therefore, the development of broad collections of original moieties endowed with heterogeneous rates/mechanisms of H2S release and a variety of physicochemical, biological and pharmacological features is the most timely and compelling issue in the field of H2S-based drug discovery.

  4. Hydrogen Sulfide and Cellular Redox Homeostasis

    PubMed Central

    Xie, Zhi-Zhong; Liu, Yang; Bian, Jin-Song

    2016-01-01

    Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S) is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H2S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H2S are still poorly comprehended. This review presents an overview of the current understanding of H2S specially focusing on the new understanding and mechanisms of the antioxidant effects of H2S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H2S-induced S-sulfhydration of key proteins (e.g., p66Shc and Keap1) is also one of the focuses of this review. PMID:26881033

  5. H2S: a novel gasotransmitter that signals by sulfhydration

    PubMed Central

    Paul, Bindu D.; Snyder, Solomon H.

    2015-01-01

    Hydrogen sulfide is a member of the growing family of gasotransmitters. Once regarded as a noxious molecule predominantly present in the atmosphere, H2S is now known to be synthesized endogenously in mammals. H2S participates in a myriad of physiological processes ranging from regulation of blood pressure to neuroprotection. Its chemical nature precludes H2S from being stored in vesicles and acting on receptor proteins in the fashion of other chemical messengers. Thus, novel cellular mechanisms have evolved to mediate its effects. This article focuses on sulfhydration (or persulfidation), which appears to be the principal post-translational modification elicited by H2S. PMID:26439534

  6. Eukaryotic and prokaryotic contributions to colonic hydrogen sulfide synthesis.

    PubMed

    Flannigan, Kyle L; McCoy, Kathy D; Wallace, John L

    2011-07-01

    Hydrogen sulfide (H(2)S) is an important modulator of many aspects of digestive function, both in health and disease. Colonic tissue H(2)S synthesis increases markedly during injury and inflammation and appears to contribute to resolution. Some of the bacteria residing in the colon can also produce H(2)S. The extent to which bacterial H(2)S synthesis contributes to what is measured as colonic H(2)S synthesis is not clear. Using conventional and germ-free mice, we have delineated the eukaryotic vs. prokaryotic contributions to colonic H(2)S synthesis, both in healthy and colitic mice. Colonic tissue H(2)S production is entirely dependent on the presence of the cofactor pyridoxal 5'-phosphate (vitamin B(6)), while bacterial H(2)S synthesis appears to occur independent of this cofactor. As expected, approximately one-half of the H(2)S produced by feces is derived from eukaryotic cells. While colonic H(2)S synthesis is markedly increased when the tissue is inflamed, and, in proportion to the extent of inflammation, fecal H(2)S synthesis does not change and tissue granulocytes do not appear to be the source of the elevated H(2)S production. Rats fed a B vitamin-deficient diet for 6 wk exhibited significantly diminished colonic H(2)S synthesis, but fecal H(2)S synthesis was not different from that of rats on the control diet. Our results demonstrate that H(2)S production by colonic bacteria does not contribute significantly to what is measured as colonic tissue H(2)S production, using the acetate trapping assay system employed in this study.

  7. Role of cGMP in hydrogen sulfide signaling.

    PubMed

    Bibli, Sofia-Iris; Yang, Guangdong; Zhou, Zongmin; Wang, Rui; Topouzis, Stavros; Papapetropoulos, Andreas

    2015-04-30

    The importance of hydrogen sulfide (H2S) in physiology and disease is being increasingly recognized in recent years. Unlike nitric oxide (NO) that signals mainly through soluble guanyl cyclase (sGC)/cGMP, H2S is more promiscuous, affecting multiple pathways. It interacts with ion channels, enzymes, transcription factors and receptors. It was originally reported that H2S does not alter the levels of cyclic nucleotides. More recent publications, however, have shown increases in intracellular cGMP following exposure of cells or tissues to exogenously administered or endogenously produced H2S. Herein, we discuss the evidence for the participation of cGMP in H2S signaling and reconcile the seemingly divergent results presented in the literature on the role of this cyclic nucleotide in the biological actions of H2S. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Detoxification of hydrogen sulfide and methanethiol in the cecal mucosa.

    PubMed

    Levitt, M D; Furne, J; Springfield, J; Suarez, F; DeMaster, E

    1999-10-01

    Colonic bacteria liberate large quantities of the highly toxic gases hydrogen sulfide (H(2)S) and methanethiol (CH(3)SH). The colonic mucosa presumably has an efficient means of detoxifying these compounds, which is thought to occur through methylation of H(2)S to CH(3)SH and CH(3)SH to dimethylsulfide (CH(3)SCH(3)). We investigated this detoxification pathway by incubating rat cecal mucosal homogenates with gas containing H(2)S, CH(3)SH, or CH(3)SCH(3). Neither CH(3)SH nor CH(3)SCH(3) was produced during H(2)S catabolism, whereas catabolism of CH(3)SH liberated H(2)S but not CH(3)SCH(3). Thus, H(2)S and CH(3)SH are not detoxified by methylation to CH(3)SCH(3). Rather, CH(3)SH is demethylated to H(2)S, and H(2)S is converted to nonvolatile metabolites. HPLC analysis of the homogenate showed the metabolite to be primarily thiosulfate. Analysis of cecal venous blood obtained after intracecal instillation of H(2)(35)S revealed that virtually all absorbed H(2)S had been oxidized to thiosulfate. The oxidation rate of H(2)S by colonic mucosa was 10,000 times greater than the reported methylation rate. Conversion to thiosulfate appears to be the mechanism whereby the cecal mucosa protects itself from the injurious effects of H(2)S and CH(3)SH, and defects in this detoxification possibly could play a role in colonic diseases such as ulcerative colitis.

  9. Detoxification of H(2)S by differentiated colonic epithelial cells: implication of the sulfide oxidizing unit and of the cell respiratory capacity.

    PubMed

    Mimoun, Sabria; Andriamihaja, Mireille; Chaumontet, Catherine; Atanasiu, Calina; Benamouzig, Robert; Blouin, Jean Marc; Tomé, Daniel; Bouillaud, Frédéric; Blachier, François

    2012-07-01

    Sulfide is released in the large intestine lumen by the microbiota and is an inhibitor of mitochondrial respiration and a genotoxic agent in colonocytes when present in excess. Deciphering how colonocytes metabolize sulfide is an important issue. In this study, using the human colonic epithelial HT-29 Glc(-/+) cells, we found that 50 μM sodium hydrogen sulfide represents the threshold of concentration above which respiration is decreased. The capacity of HT-29 Glc(-/+) cells to oxidize lower concentration of sulfide was associated with the expression of transcripts corresponding to the enzymes of the sulfide oxidizing unit (SOU), that is, sulfide quinone reductase (SQR), dioxygenase ethylmalonic encephalopathy, and thiosulfate sulfur transferase (TST). Inhibition of cell O(2) consumption by sulfide was reverted by zinc but not by calcium and iron. When the cells undergo either spontaneous or butyrate-induced differentiation, their capacity to oxidize sulfide was significantly increased. The expression levels of the genes corresponding to the enzymes of the SOU were not increased, whereas increased cellular maximal respiratory capacity and oxygen consumption by the dioxygenase were both measured. In human biopsies recovered from various parts of the large intestine, the three enzymes of the SOU were expressed. SOU and cell respiratory capacity are crucial for sulfide detoxification in colonocytes. Sulfide oxidative capacity in the colonic mucosa is higher in differentiated than in proliferative epithelial cells. The cell respiratory capacity and SOU activity appear to represent major determinants allowing sulfide detoxification in colonic epithelial cells.

  10. Growth and Characterization of Zinc Sulfide Films by Conversion of Zinc Oxide Films with H2S

    DTIC Science & Technology

    1989-09-26

    zinc vide single crystal (12). The peak position of the absorption band of the zinc sulfide films was at 278 cm - 1. Kwasniewski (13) reported a broad...11, 190 (1959). 13. E. A. Kwasniewski , E. S. Koteles and W. R. Datars, Can. J. Phys., 54, 1053 (1976). 14. 0. Brafman and S. S. Mitra, Phys. Rev., 171

  11. Growth and Characterization of Zinc Sulfide Films by Conversion of Zinc Oxide Films with H2S

    DTIC Science & Technology

    1989-09-26

    of the absorption band of the zinc sulfide films was at 278 cm-’. Kwasniewski (13) reported a broad absorption band covering 250 - 355 cm-’ in the...Collins and D. A. Kleinman, J. Phys. Chem. Solids, 11, 190 (1959). 13. E. A. Kwasniewski , E. S. Koteles and W. R. DaLars, Can. J. Phys., 54, 1053

  12. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs.

    PubMed

    Klatt, Judith M; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-09-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2 S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2 S: (i) H2 S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2 S on photosystem I components and/or on the Calvin cycle. (ii) H2 S concentrations of up to 210 μM temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2 S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2 S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2 S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2 S concentrations, such as those occurring in microbial mats and biofilms.

  13. Nanostructured N-doped TiO2 marigold flowers for an efficient solar hydrogen production from H2S

    NASA Astrophysics Data System (ADS)

    Chaudhari, Nilima S.; Warule, Sambhaji S.; Dhanmane, Sushil A.; Kulkarni, Milind V.; Valant, Matjaz; Kale, Bharat B.

    2013-09-01

    Nitrogen-doped TiO2 nanostructures in the form of marigold flowers have been synthesized for the first time using a facile solvothermal method. The structural analysis has shown that such an N-doped TiO2 system crystallizes in the anatase structure. The optical absorption spectra have clearly shown the shift in the absorption edge towards the visible-light range, which indicates successful nitrogen doping. The nitrogen doping has been further confirmed by photoluminescence and photoemission spectroscopy. Microscopy studies have shown the thin nanosheets (petals) of N-TiO2 with a thickness of ~2-3 nm, assembled in the form of the marigold flower with a high surface area (224 m2 g-1). The N-TiO2 nanostructure with marigold flowers is an efficient photocatalyst for the decomposition of H2S and production of hydrogen under solar light. The maximum hydrogen evolution obtained is higher than other known N-TiO2 systems. It is noteworthy that photohydrogen production using the unique marigold flowers of N-TiO2 from abundant H2S under solar light is hitherto unattempted. The proposed synthesis method can also be utilized to design other hierarchical nanostructured N-doped metal oxides.Nitrogen-doped TiO2 nanostructures in the form of marigold flowers have been synthesized for the first time using a facile solvothermal method. The structural analysis has shown that such an N-doped TiO2 system crystallizes in the anatase structure. The optical absorption spectra have clearly shown the shift in the absorption edge towards the visible-light range, which indicates successful nitrogen doping. The nitrogen doping has been further confirmed by photoluminescence and photoemission spectroscopy. Microscopy studies have shown the thin nanosheets (petals) of N-TiO2 with a thickness of ~2-3 nm, assembled in the form of the marigold flower with a high surface area (224 m2 g-1). The N-TiO2 nanostructure with marigold flowers is an efficient photocatalyst for the decomposition of H2S and

  14. Identification of H2S3 and H2S produced by 3-mercaptopyruvate sulfurtransferase in the brain.

    PubMed

    Kimura, Yuka; Toyofuku, Yukiko; Koike, Shin; Shibuya, Norihiro; Nagahara, Noriyuki; Lefer, David; Ogasawara, Yuki; Kimura, Hideo

    2015-10-06

    Hydrogen polysulfides (H2Sn) have a higher number of sulfane sulfur atoms than hydrogen sulfide (H2S), which has various physiological roles. We recently found H2Sn in the brain. H2Sn induced some responses previously attributed to H2S but with much greater potency than H2S. However, the number of sulfur atoms in H2Sn and its producing enzyme were unknown. Here, we detected H2S3 and H2S, which were produced from 3-mercaptopyruvate (3 MP) by 3-mercaptopyruvate sulfurtransferase (3MST), in the brain. High performance liquid chromatography with fluorescence detection (LC-FL) and tandem mass spectrometry (LC-MS/MS) analyses showed that H2S3 and H2S were produced from 3 MP in the brain cells of wild-type mice but not 3MST knockout (3MST-KO) mice. Purified recombinant 3MST and lysates of COS cells expressing 3MST produced H2S3 from 3 MP, while those expressing defective 3MST mutants did not. H2S3 was localized in the cytosol of cells. H2S3 was also produced from H2S by 3MST and rhodanese. H2S2 was identified as a minor H2Sn, and 3 MP did not affect the H2S5 level. The present study provides new insights into the physiology of H2S3 and H2S, as well as novel therapeutic targets for diseases in which these molecules are involved.

  15. The role of hydrogen sulfide in stroke

    PubMed Central

    Dou, Yang; Wang, Zhong; Chen, Gang

    2016-01-01

    Stroke is a kind of acute cerebrovascular disease characterized by the focal lack of neurological function, including ischemic stroke and hemorrhagic stroke. As society ages rapidly, stroke has become the second leading cause of disability and death, and also become the main threat to human health and life. In recent years, findings from increasing animal and clinical trials have supplied scientific evidences for the treatment of stroke. Hydrogen sulfide (H2S), which has always been seen as a toxic gas, now has been thought to be the third gaseous signaling molecule following nitric oxide and carbon monoxide. Accumulating evidences indicate that H2S plays an important role in stroke. Given that its neuroprotective effect is dose-dependent, only when its concentration is relatively low, H2S can yield the neuroprotection, while high dose may lead to neurotoxicity. All these study results suggest that H2S may offer a new promising application for the therapy of stroke. Here, our review will present the role of H2S in stroke from its mechanism to animal and clinical studies. PMID:27867473

  16. Enamel surface changes caused by hydrogen sulfide

    PubMed Central

    Yamaguchi, Takao; Hanabusa, Masao; Hosoya, Noriyasu; Chiba, Toshie; Yoshida, Takumasa; Morito, Akiyuki

    2015-01-01

    Background: Volatile sulfur compounds (VSCs) produced inside the mouth are a well-known cause of halitosis. Recent studies have suggested that VSCs modify the pathology of periodontitis by encouraging the migration of bacterial toxins associated with increased permeability of gingival epithelia, and enhancing the production of matrix metalloproteinases in gingival connective tissue. Nonetheless, the effects on the enamel of direct exposure to VSCs within the oral cavity remain unclear. In the present study, we observed the effects of VSCs in the form of hydrogen sulfide (H2S) on enamel surfaces and determined their effects on restorations. Materials and Methods: Extracted human tooth and bovine tooth samples were divided into the H2S experimental side and the control side. We observed the effects of H2S on enamel surfaces using electron microscopy and conducted a shear test. Results: We found that exposure to H2S obscured the enamel surface's crystal structure. The surface also exhibited coarseness and reticular changes. Shear testing did not reveal any differences in bond strength. Conclusions: Our findings suggested that H2S occurring inside the mouth causes changes to the crystal structure of the enamel surface that can lead to tooth wear, but that it does not diminish the effects of dental bonding in adhesive restorations. PMID:26752833

  17. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract

    PubMed Central

    Singh, Sudha B.; Lin, Henry C.

    2015-01-01

    Hydrogen sulfide (H2S) is a Janus-faced molecule. On one hand, several toxic functions have been attributed to H2S and exposure to high levels of this gas is extremely hazardous to health. On the other hand, H2S delivery based clinical therapies are being developed to combat inflammation, visceral pain, oxidative stress related tissue injury, thrombosis and cancer. Since its discovery, H2S has been found to have pleiotropic effects on physiology and health. H2S is a gasotransmitter that exerts its effect on different systems, such as gastrointestinal, neuronal, cardiovascular, respiratory, renal, and hepatic systems. In the gastrointestinal tract, in addition to H2S production by mammalian cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE), H2S is also generated by the metabolic activity of resident gut microbes, mainly by colonic Sulfate-Reducing Bacteria (SRB) via a dissimilatory sulfate reduction (DSR) pathway. In the gut, H2S regulates functions such as inflammation, ischemia/ reperfusion injury and motility. H2S derived from gut microbes has been found to be associated with gastrointestinal disorders such as ulcerative colitis, Crohn’s disease and irritable bowel syndrome. This underscores the importance of gut microbes and their production of H2S on host physiology and pathophysiology. PMID:27682122

  18. Biochemistry and therapeutic potential of hydrogen sulfide - reality or fantasy?

    PubMed

    Brodek, Paulina; Olas, Beata

    2016-08-11

    Hydrogen sulfide (H2S) is a signaling gasotransmitter, involved in different physiological and pathological processes. H2S regulates apoptosis, the cell cycle and oxidative stress. H2S exerts powerful effects on smooth muscle cells, endothelial cells, inflammatory cells, endoplasmic reticulum, mitochondria and nuclear transcription factors. H2S is known to be produced from L-cysteine, D-cysteine and L-homocysteine in the body. Four enzymes - cystathionine-b synthase (CBS), mercaptopyruvate sulfurtransferase (3-MST), cystathionine-γ lyase (CSE) and cysteine aminotransferase (CAT) - are involved in H2S synthesis. The biosynthetic pathway for the production of H2S from D-cysteine involves 3-MST and D-amino acid oxidase (DAO). The therapeutic potential of H2S is not clear. However, recently results have demonstrated that H2S has protective action for ischemic heart disease or hypertension, and protects against ischemia of the brain. This review summarizes the negative and the positive roles of H2S in various biological systems, for example the cardiovascular system and nervous system. We also discuss the function of classical, therapeutic and natural (for example garlic) donors of H2S in pre-clinical and clinical studies.

  19. Electronic structure of H2S, SF2, and HSF and implications for hydrogen-substituted hypervalent sulfur fluorides.

    PubMed

    Lindquist, Beth A; Woon, David E; Dunning, Thom H

    2014-02-20

    It is well known that hypervalent molecules are more stable with very electronegative ligands such as fluorine. For example, while SF6 is uniquely stable and experimentally well characterized and many of the features of SF4 have been characterized, neither H4S nor H6S has been observed. Furthermore, no hypervalent sulfur species with mixed hydrogen and fluorine ligands have been experimentally characterized to date. In this work, we present detailed calculations of the electronic structure of H2S, SF2, and HSF. While all three compounds have similar bent singlet ground states, the potential energy surfaces of various low lying electronic states as a function of bond angle reveal very different behaviors, in particular for linear geometries. We use the disparate bonding motifs of the low-lying triplet states to rationalize the differences between SF4 and the hypothetical H4S molecule. We also make predictions about the effects of hydrogen substitution on the energetics and geometries of hypervalent sulfur fluoride compounds.

  20. Reaction between H2, CO, and H2S over Fe,Ni metal in the solar nebula: Experimental evidence for the formation of sulfur-bearing organic molecules and sulfides

    NASA Astrophysics Data System (ADS)

    Llorca, Jordi; Casanova, Ignasi

    2000-07-01

    Detailed laboratory studies have been carried out in order to simulate the interaction between nanometer-sized kamacite metal particles and different gas mixtures consisting of H2:H2S (250:0.1), H2:CO (250:1) and H2:CO:H2S (250:1:0.1) under nebular-type conditions (5x10-4 atm and 473 K). Reaction of H2+H2S with kamacite particles for 1000 h leads to the formation of pyrrhotite. Incorporation of CO into the gaseous reactant mixture results in the formation of both sulfide and carbide phases. At the same time, amorphous carbon is deposited onto the metal particles and organic molecules are evolved, namely hydrocarbons and thiols in the C1-C5 and C1-C2 range, respectively. Carbon deposition and production of organics are enhanced with respect to experiments performed with H2+CO, where a carbide phase is formed. There is no evidence for the existence of sulfur poisoning effects on the metal-catalysed hydrogenation of CO through Fischer-Tropsch-type reactions in nebular environments. In fact, it is experimentally demonstrated that sulfur-containing organic species could be synthesized by such reactions from nebular gas.

  1. Is hydrogen sulfide a circulating "gasotransmitter" in vertebrate blood?

    PubMed

    Olson, Kenneth R

    2009-07-01

    Hydrogen sulfide (H(2)S) is gaining acceptance as a signaling molecule and has been shown to elicit a variety of biological effects at concentrations between 10 and 1000 micromol/l. Dissolved H(2)S is a weak acid in equilibrium with HS(-) and S(2-) and under physiological conditions these species, collectively referred to as sulfide, exist in the approximate ratio of 20% H(2)S, 80% HS(-) and 0% S(2-). Numerous analyses over the past 8 years have reported plasma or blood sulfide concentrations also in this range, typically between 30 and 300 micromol/l, thus supporting the biological studies. However, there is some question whether or not these concentrations are physiological. First, many of these values have been obtained from indirect methods using relatively harsh chemical conditions. Second, most studies conducted prior to 2000 failed to find blood sulfide in micromolar concentrations while others showed that radiolabeled (35)S-sulfide is rapidly removed from blood and that mammals have a relatively high capacity to metabolize exogenously administered sulfide. Very recent studies using H(2)S gas-sensing electrodes to directly measure sulfide in plasma or blood, or HPLC analysis of head-space gas, have also indicated that sulfide does not circulate at micromolar levels and is rapidly consumed by blood or tissues. Third, micromolar concentrations of sulfide in blood or exhaled air should be, but are not, malodorous. Fourth, estimates of dietary sulfur necessary to sustain micromolar levels of plasma sulfide greatly exceed the daily intake. Collectively, these studies imply that many of the biological effects of sulfide are only achieved at supra-physiological concentrations and they question whether circulating sulfide is a physiologically relevant signaling molecule. This review examines the blood/plasma sulfide measurements that have been reported over the past 30 years from the perspective of the analytical methods used and the potential sources of error.

  2. International Union of Basic and Clinical Pharmacology. CII: Pharmacological Modulation of H2S Levels: H2S Donors and H2S Biosynthesis Inhibitors.

    PubMed

    Szabo, Csaba; Papapetropoulos, Andreas

    2017-10-01

    Over the last decade, hydrogen sulfide (H2S) has emerged as an important endogenous gasotransmitter in mammalian cells and tissues. Similar to the previously characterized gasotransmitters nitric oxide and carbon monoxide, H2S is produced by various enzymatic reactions and regulates a host of physiologic and pathophysiological processes in various cells and tissues. H2S levels are decreased in a number of conditions (e.g., diabetes mellitus, ischemia, and aging) and are increased in other states (e.g., inflammation, critical illness, and cancer). Over the last decades, multiple approaches have been identified for the therapeutic exploitation of H2S, either based on H2S donation or inhibition of H2S biosynthesis. H2S donation can be achieved through the inhalation of H2S gas and/or the parenteral or enteral administration of so-called fast-releasing H2S donors (salts of H2S such as NaHS and Na2S) or slow-releasing H2S donors (GYY4137 being the prototypical compound used in hundreds of studies in vitro and in vivo). Recent work also identifies various donors with regulated H2S release profiles, including oxidant-triggered donors, pH-dependent donors, esterase-activated donors, and organelle-targeted (e.g., mitochondrial) compounds. There are also approaches where existing, clinically approved drugs of various classes (e.g., nonsteroidal anti-inflammatories) are coupled with H2S-donating groups (the most advanced compound in clinical trials is ATB-346, an H2S-donating derivative of the non-steroidal anti-inflammatory compound naproxen). For pharmacological inhibition of H2S synthesis, there are now several small molecule compounds targeting each of the three H2S-producing enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase. Although many of these compounds have their limitations (potency, selectivity), these molecules, especially in combination with genetic approaches, can be instrumental for the delineation of the

  3. Therapeutic application of hydrogen sulfide donors: the potential and challenges.

    PubMed

    Wu, Dan; Hu, Qingxun; Zhu, Yizhun

    2016-03-01

    Hydrogen sulfide (H2S), a colorless gas smelling of rotten egg, has long been considered a toxic gas and environment hazard. However, evidences show that H2S plays a great role in many physiological and pathological activities, and it exhibits different effects when applied at various doses. In this review, we summarize the chemistry and biomedical applications of H2S-releasing compounds, including inorganic salts, phosphorodithioate derivatives, derivatives of Allium sativum extracts, derivatives of thioaminoacids, and derivatives of antiinflammatory drugs.

  4. Geothermal hydrogen sulfide removal

    SciTech Connect

    Urban, P.

    1981-04-01

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  5. Developing sulfide-oxidizing biofilm on H2S-exhausted carbon for sustainable bio-regeneration and biofiltration.

    PubMed

    Jiang, Xia; Yan, Rong; Tay, Joo Hwa

    2009-05-30

    The feasibility of developing biofilm on exhausted carbon using pre-deposited sulfur compounds as the sole energy source was studied, aiming to re-use them in odor biofiltration. The exhausted carbon with different properties, including surface pH, sulfur content and porosity, was used. A series of off-line trials were conducted to investigate the release of sulfur compounds from the exhausted carbon and the attachment of sulfide-oxidizing bacteria on the exhausted carbon. Without any pre-treatment, a few bacteria attachment on exhausted carbon was observed by SEM, due to possibly the limitation of reduced sulfur compounds release for bacterial growth. The biofilm development was much improved by adding NaOH solution to partially pre-desorb the deposited sulfur into liquid phase, which provided initial energy for bacterial growth. With the attached bacteria, the further significant release of the deposited sulfur was achieved through an additional driving force: biodegradation. The key issues for developing biofilm on exhausted carbon were concluded, which mainly concerned of desorption of pre-deposited reduced sulfur compounds and porosity of carbon. The sulfur-associated reactions occurring in developing biofilm on exhausted carbon was proposed. Bio-regeneration of exhausted carbon in the course of biofilm development was also preliminarily assessed.

  6. Role of Hydrogen Sulfide in Ischemia-Reperfusion Injury

    PubMed Central

    Wu, Dongdong; Wang, Jun; Li, Hui; Xue, Mengzhou; Ji, Ailing; Li, Yanzhang

    2015-01-01

    Ischemia-reperfusion (I/R) injury is one of the major causes of high morbidity, disability, and mortality in the world. I/R injury remains a complicated and unresolved situation in clinical practice, especially in the field of solid organ transplantation. Hydrogen sulfide (H2S) is the third gaseous signaling molecule and plays a broad range of physiological and pathophysiological roles in mammals. H2S could protect against I/R injury in many organs and tissues, such as heart, liver, kidney, brain, intestine, stomach, hind-limb, lung, and retina. The goal of this review is to highlight recent findings regarding the role of H2S in I/R injury. In this review, we present the production and metabolism of H2S and further discuss the effect and mechanism of H2S in I/R injury. PMID:26064416

  7. Observation of superconductivity in hydrogen sulfide from nuclear resonant scattering.

    PubMed

    Troyan, Ivan; Gavriliuk, Alexander; Rüffer, Rudolf; Chumakov, Alexander; Mironovich, Anna; Lyubutin, Igor; Perekalin, Dmitry; Drozdov, Alexander P; Eremets, Mikhail I

    2016-03-18

    High-temperature superconductivity remains a focus of experimental and theoretical research. Hydrogen sulfide (H2S) has been reported to be superconducting at high pressures and with a high transition temperature. We report on the direct observation of the expulsion of the magnetic field in H2S compressed to 153 gigapascals. A thin (119)Sn film placed inside the H2S sample was used as a sensor of the magnetic field. The magnetic field on the (119)Sn sensor was monitored by nuclear resonance scattering of synchrotron radiation. Our results demonstrate that an external static magnetic field of about 0.7 tesla is expelled from the volume of (119)Sn foil as a result of the shielding by the H2S sample at temperatures between 4.7 K and approximately 140 K, revealing a superconducting state of H2S.

  8. Sulfur as a Signaling Nutrient Through Hydrogen Sulfide

    PubMed Central

    Kabil, Omer; Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H2S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H2S-based therapeutics is hampered by fundamental gaps in our knowledge of how H2S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H2S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease. PMID:25033061

  9. Brain hydrogen sulfide is severely decreased in Alzheimer's disease.

    PubMed

    Eto, Ko; Asada, Takashi; Arima, Kunimasa; Makifuchi, Takao; Kimura, Hideo

    2002-05-24

    Although hydrogen sulfide (H2S) is generally thought of in terms of a poisonous gas, it is endogenously produced in the brain from cysteine by cystathionine beta-synthase (CBS). H2S functions as a neuromodulator as well as a smooth muscle relaxant. Here we show that the levels of H2S are severely decreased in the brains of Alzheimer's disease (AD) patients compared with the brains of the age matched normal individuals. In addition to H2S production CBS also catalyzes another metabolic pathway in which cystathionine is produced from the substrate homocysteine. Previous findings, which showed that S-adenosyl-l-methionine (SAM), a CBS activator, is much reduced in AD brain and that homocysteine accumulates in the serum of AD patients, were confirmed. These observations suggest that CBS activity is reduced in AD brains and the decrease in H2S may be involved in some aspects of the cognitive decline in AD.

  10. Hydrogen Sulfide Chemical Biology: Pathophysiological roles and detection

    PubMed Central

    Kolluru, Gopi K; Shen, Xinggui; Bir, Shyamal C.; Kevil, Christopher G.

    2014-01-01

    Hydrogen sulfide (H2S) is the most recent endogenous gasotransmitter that has been reported to serve many physiological and pathological functions in different tissues. Studies over the past decade have revealed that H2S can be synthesized through numerous pathways and its bioavailability regulated through its conversion into different biochemical forms. H2S exerts its biological effects in various manners including redox regulation of protein and small molecular weight thiols, polysulfides, thiosulfate/sulfite, iron-sulfur cluster proteins, and anti-oxidant properties that affect multiple cellular and molecular responses. However, precise measurement of H2S bioavailability and its associated biochemical and pathophysiological roles remains less well understood. In this review, we discuss recent understanding of H2S chemical biology, its relationship to tissue pathophysiological responses and possible therapeutic uses. PMID:23850632

  11. THE GENUS VEILLONELLA. 3. HYDROGEN SULFIDE PRODUCTION BY GROWING CULTURES.

    PubMed

    ROGOSA, M; BISHOP, F S

    1964-07-01

    Rogosa, Morrison (National Institute of Dental Research, Bethesda, Md.), and Ferial S. Bishop. The genus Veillonella. III. Hydrogen sulfide production by growing cultures. J. Bacteriol. 88:37-41. 1964.-The conditions necessary for H(2)S production by 105 strains of Veillonella, from a variety of sources and comprising seven anti-genic groups, are presented and discussed. All strains, during 1 to 2 days of growth, produced H(2)S in a defined medium supplemented with proper amounts of l-cysteine, l-cystine, reduced glutathione, thiosulfate, thiocyanate, or thioglycolate. Erratic or negative results were obtained with some commonly used media containing yeast extract and casein digest, but which were not supplemented with appropriate substrates for H(2)S production. Previous literature descriptions of V. alcalescens as not producing H(2)S are incorrect; H(2)S production, or the previously presumed lack of it, cannot be used as a criterion differentiating V. alcalescens from V. parvula.

  12. Oxidation of hydrogen sulfide by human liver mitochondria.

    PubMed

    Helmy, Nada; Prip-Buus, Carina; Vons, Corinne; Lenoir, Véronique; Abou-Hamdan, Abbas; Guedouari-Bounihi, Hala; Lombès, Anne; Bouillaud, Frédéric

    2014-09-15

    Hydrogen sulfide (H2S) is the third gasotransmitter discovered. Sulfide shares with the two others (NO and CO) the same inhibiting properties towards mitochondrial respiration. However, in contrast with NO or CO, sulfide at concentrations lower than the toxic (μM) level is an hydrogen donor and a substrate for mitochondrial respiration. This is due to the activity of a sulfide quinone reductase found in a large majority of mitochondria. An ongoing study of the metabolic state of liver in obese patients allowed us to evaluate the sulfide oxidation capacity with twelve preparations of human liver mitochondria. The results indicate relatively high rates of sulfide oxidation with a large variability between individuals. These observations made with isolated mitochondria appear in agreement with the main characteristics of sulfide oxidation as established before with the help of cellular models.

  13. Hydrogen sulfide production from subgingival plaque samples.

    PubMed

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket.

  14. A FRET enzyme-based probe for monitoring hydrogen sulfide.

    PubMed

    Strianese, Maria; Palm, Gottfried J; Milione, Stefano; Kühl, Olaf; Hinrichs, Winfried; Pellecchia, Claudio

    2012-11-05

    Fluorescently labeled cobalt peptide deformylase (Co-PDF) can be efficiently used as a fluorescence-resonance-energy-transfer-based sensing device for hydrogen sulfide (H(2)S). The proof of concept of our sensor system is substantiated by spectroscopic, structural, and theoretical results. Monohydrogen sulfide coordination to Co-PDF and Ni-PDF was verified by X-ray crystallography. Density functional theory calculations were performed to gain insight into the characteristics of the coordination adduct between H(2)S and the cobalt cofactor in Co-PDF.

  15. The Role of Hydrogen Sulfide in Renal System

    PubMed Central

    Cao, Xu; Bian, Jin-Song

    2016-01-01

    Hydrogen sulfide has gained recognition as the third gaseous signaling molecule after nitric oxide and carbon monoxide. This review surveys the emerging role of H2S in mammalian renal system, with emphasis on both renal physiology and diseases. H2S is produced redundantly by four pathways in kidney, indicating the abundance of this gaseous molecule in the organ. In physiological conditions, H2S was found to regulate the excretory function of the kidney possibly by the inhibitory effect on sodium transporters on renal tubular cells. Likewise, it also influences the release of renin from juxtaglomerular cells and thereby modulates blood pressure. A possible role of H2S as an oxygen sensor has also been discussed, especially at renal medulla. Alternation of H2S level has been implicated in various pathological conditions such as renal ischemia/reperfusion, obstructive nephropathy, diabetic nephropathy, and hypertensive nephropathy. Moreover, H2S donors exhibit broad beneficial effects in renal diseases although a few conflicts need to be resolved. Further research reveals that multiple mechanisms are underlying the protective effects of H2S, including anti-inflammation, anti-oxidation, and anti-apoptosis. In the review, several research directions are also proposed including the role of mitochondrial H2S in renal diseases, H2S delivery to kidney by targeting D-amino acid oxidase/3-mercaptopyruvate sulfurtransferase (DAO/3-MST) pathway, effect of drug-like H2S donors in kidney diseases and understanding the molecular mechanism of H2S. The completion of the studies in these directions will not only improves our understanding of renal H2S functions but may also be critical to translate H2S to be a new therapy for renal diseases. PMID:27803669

  16. [Relationship between hydrogen sulfide and myocardial damage in endotoxemic rats].

    PubMed

    Xian, Xiao-Hui; Huang, Xin-Li; Zhou, Xiao-Hong; Zhang, Jing-Kun; Ling, Yi-Ling

    2007-06-25

    To investigate the changes and role of hydrogen sulfide (H2S) in myocardial damage in endotoxemic rats, a rat model of endotoxemia induced by injection of lipopolysaccharide (LPS) was developed. Male Wistar rats were divided into four groups: control group, LPS group, LPS + propargylglycine (PPG, a metabolic enzyme inhibitor of H2S) group and LPS + NaHS (H2S donor) group. The mean arterial pressure (MAP) of rats within 4 h was observed, TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity in cardiac muscles were determined. The morphological structure of cardiac muscle was observed. Administration of LPS caused a sustained fall in MAP within 4 h, and significant increases in TNF-alpha and H2S contents in plasma (P<0.05). Plasmic H2S content was negatively correlated with MAP (r = -0.936, -0.913 and -0.908 at 1, 2 and 4 h, respectively, P<0.05). LPS also induced increases in TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles and myocardial damage. Treatment with PPG reduced the increases in TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles, ameliorated the hypotensive effect and myocardial damage caused by LPS administration (P<0.05). However, treatment with NaHS increased TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles, and aggravated the hypotensive action and tissue injuries caused by LPS administration (P<0.05). It is suggested that hypotension and myocardial damage in endotoxemic rats are partly induced by increase in H2S content.

  17. Self-Immolative Thiocarbamates Provide Access to Triggered H2S Donors and Analyte Replacement Fluorescent Probes.

    PubMed

    Steiger, Andrea K; Pardue, Sibile; Kevil, Christopher G; Pluth, Michael D

    2016-06-15

    Hydrogen sulfide (H2S) is an important biological signaling molecule, and chemical tools for H2S delivery and detection have emerged as important investigative methods. Key challenges in these fields include developing donors that are triggered to release H2S in response to stimuli and developing probes that do not irreversibly consume H2S. Here we report a new strategy for H2S donation based on self-immolation of benzyl thiocarbamates to release carbonyl sulfide, which is rapidly converted to H2S by carbonic anhydrase. We leverage this chemistry to develop easily modifiable donors that can be triggered to release H2S. We also demonstrate that this approach can be coupled with common H2S-sensing motifs to generate scaffolds which, upon reaction with H2S, generate a fluorescence response and also release caged H2S, thus addressing challenges of analyte homeostasis in reaction-based probes.

  18. The cardioprotective actions of hydrogen sulfide in acute myocardial infarction and heart failure.

    PubMed

    Polhemus, David J; Calvert, John W; Butler, Javed; Lefer, David J

    2014-01-01

    It has now become universally accepted that hydrogen sulfide (H2S), previously considered only as a lethal toxin, has robust cytoprotective actions in multiple organ systems. The diverse signaling profile of H2S impacts multiple pathways to exert cytoprotective actions in a number of pathological states. This paper will review the recently described cardioprotective actions of hydrogen sulfide in both myocardial ischemia/reperfusion injury and congestive heart failure.

  19. Role of H2S Donors in Cancer Biology.

    PubMed

    Lee, Zheng-Wei; Deng, Lih-Wen

    2015-01-01

    Hydrogen sulfide (H2S) donors including organosulfur compounds (OSC), inorganic sulfide salts, and synthetic compounds are useful tools in studies to elucidate the effects of H2S in cancer biology. Studies using such donors have shown the ability of H2S to suppress tumor growth both in vitro and in vivo, with some of them suggesting the selectivity of its cytotoxic effects to cancer cells. In addition to promoting cancer cell death, H2S donors were also found to inhibit cancer angiogenesis and metastasis. The underlying mechanisms for the anticancer activities of H2S involve (1) cell signaling pathways, such as MAPK and STAT; (2) cell cycle regulation; (3) microRNAs regulation; and (4) cancer metabolism and pH regulation. Altogether, compiling evidences have demonstrated the great potential of using H2S donors as anticancer agents. Nevertheless, the application and development of H2S for therapy are still facing challenges as identification of molecular targets of H2S awaits further investigation.

  20. Endogenous mitigation of H2S inside of the landfills.

    PubMed

    Fang, Yuan; Zhong, Zhong; Shen, Dongsheng; Du, Yao; Xu, Jing; Long, Yuyang

    2016-02-01

    Vast quantities of hydrogen sulfide (H2S) emitted from landfill sites require urgent disposal. The current study focused on source control and examined the migration and conversion behavior of sulfur compounds in two lab-scale simulated landfills with different operation modes. It aimed to explore the possible strategies and mechanisms for H2S endogenous mitigation inside of landfills during decomposition. It was found that the strength of H2S emissions from the landfill sites was dependent on the municipal solid waste (MSW) degradation speed and vertical distribution of sulfide. Leachate recirculation can shorten both the H2S influence period and pollution risk to the surrounding environment. H2S endogenous mitigation may be achieved by chemical oxidation, biological oxidation, adsorption, and/or precipitation in different stages. Migration and conversion mainly affected H2S release behavior during the initial stabilization phase in the landfill. Microbial activities related to sulfur, nitrogen, and iron can further promote H2S endogenous mitigation during the high reducing phase. Thus, H2S endogenous mitigation can be effectively enhanced via control of the aforementioned processes.

  1. Hydrogen Sulfide as a Potential Therapeutic Target in Fibrosis

    PubMed Central

    Zhang, Shufang; Pan, Chuli; Zhou, Feifei; Yuan, Zhi; Wang, Huiying; Cui, Wei; Zhang, Gensheng

    2015-01-01

    Hydrogen sulfide (H2S), produced endogenously by the activation of two major H2S-generating enzymes (cystathionine β-synthase and cystathionine γ-lyase), plays important regulatory roles in different physiologic and pathologic conditions. The abnormal metabolism of H2S is associated with fibrosis pathogenesis, causing damage in structure and function of different organs. A number of in vivo and in vitro studies have shown that both endogenous H2S level and the expressions of H2S-generating enzymes in plasma and tissues are significantly downregulated during fibrosis. Supplement with exogenous H2S mitigates the severity of fibrosis in various experimental animal models. The protective role of H2S in the development of fibrosis is primarily attributed to its antioxidation, antiapoptosis, anti-inflammation, proangiogenesis, and inhibition of fibroblasts activities. Future studies might focus on the potential to intervene fibrosis by targeting the pathway of endogenous H2S-producing enzymes and H2S itself. PMID:26078809

  2. Role of hydrogen sulfide in the physiology of penile erection.

    PubMed

    Qiu, Xuefeng; Villalta, Jackie; Lin, Guiting; Lue, Tom F

    2012-01-01

    Hydrogen sulfide (H(2)S), which is a well-known toxic gas, has recently been recognized as a biological messenger that plays an important role in physiological and pathophysiological conditions. Relatively high levels of H(2)S have been discovered in mammalian tissues. It is mainly synthesized by 2 enzymes, including cystathionine β-synthase and cystathionine γ-lysase, which utilize L-cysteine as substrate to produce H(2)S. H(2)S has been demonstrated to exhibit potent vasodilator activity both in vitro and in vivo by relaxing vascular smooth muscle. Recently, H(2)S has been discovered in penile tissue with smooth muscle relaxant effects. Furthermore, other effects of H(2)S could play a role in the physiology of erection. Understanding H(2)S in the physiology of erection might provide alternative erectile dysfunction strategies for those patients with poor or no response to type 5 phosphodiesterase inhibitors. This review intends to present the H(2)S pathway in penile tissue and the potential role of H(2)S in the physiology of erections.

  3. Passive loss of hydrogen sulfide in biological experiments.

    PubMed

    DeLeon, Eric R; Stoy, Gilbrian F; Olson, Kenneth R

    2012-02-01

    Hydrogen sulfide (H(2)S) is a volatile gas of considerable interest as a physiologically relevant signaling molecule, but this volatility has typically been overlooked in the context of biological experiments. We examined volatility of 10 and 100 μM H(2)S (Na(2)S·9H(2)O) in real time with polarographic electrodes in three commonly employed experimental apparatuses: 24-well tissue culture plates (WP), muscle myograph baths (MB), and the Langendorff perfused heart apparatus (LPH). H(2)S loss from all apparatuses was rapid and exponential, with half-times (t(1/2)) of 5 min (WP), less than 4 min (MB), and less than 0.5 min (LPH). The t(1/2) for H(2)S loss from MB bubbled with 100% oxygen was slightly longer than that for MB bubbled with 100% nitrogen; both were significantly shorter than stirred but unbubbled MB (>9 min). Therefore, even without tissue, H(2)S rapidly disappears from buffer under a variety of experimental conditions, and this is due to volatilization, not oxidation. The inability to maintain H(2)S concentration, even briefly, questions the accuracy of dose-response studies and the relevance of long-term (>10 min) exposure to a single treatment of H(2)S. These results also help to explain the discrepancy between low H(2)S concentrations in blood and tissues versus high concentrations of exogenous H(2)S required to produce physiological responses. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Hydrogen sulfide therapy in brain diseases: from bench to bedside

    PubMed Central

    Zhang, Ju-yi; Ding, Yi-ping; Wang, Zhong; Kong, Yan; Gao, Rong; Chen, Gang

    2017-01-01

    Hydrogen sulfide (H2S) has been recognized and studied for nearly 300 years, but past researches mainly focus on its toxicity effect. During the past two decades, the majority of researches have reported that H2S is a novel endogenous gaseous signal molecule in organisms, and play an important role in various systems and diseases. H2S is mainly produced by three enzymes, including cystathionine β-synthase, cystathionine γ-lyase and 3-mercaptopyruvate sulfurtransferase along with cysteine aminotransferase. H2S had been firstly reported as a neuromodulator in the brain, because of its essential role in the facilitating hippocampal long-term potentiation at physiological concentration. It is subsequently reported that H2S may have relevance to neurologic disorders through antioxidative, anti-inflammatory, anti-apoptotic and additional effects. Recent basic medical studies and preclinical studies on neurologic diseases have demonstrated that the administration of H2S at physiological or pharmacological levels attenuates brain injury. However, the neuroprotective effect of H2S is concentration-dependent, only a comparatively low dose of H2S can provide beneficial effect. Herein, we review the neuroprotevtive role of H2S therapy in brain diseases from its mechanism to clinical application in animal and human subjects, and therefore provide the potential strategies for further clinical treatment. PMID:28744364

  5. Hydrogen Sulfide as Endothelial Derived Hyperpolarizing Factor Sulfhydrates Potassium Channels

    PubMed Central

    Mustafa, Asif K.; Sikka, Gautam; Gazi, Sadia K.; Steppan, Jochen; Jung, Sung M.; Bhunia, Anil K.; Barodka, Viachaslau M.; Gazi, Farah K.; Barrow, Roxanne K.; Wang, Rui; Amzel, L. Mario; Berkowitz, Dan E.; Snyder, Solomon H.

    2011-01-01

    Rationale Nitric oxide, the classic endothelial derived relaxing factor (EDRF), acts via cyclic GMP and calcium without notably affecting membrane potential. A major component of EDRF activity derives from hyperpolarization and is termed endothelial derived hyperpolarizing factor (EDHF). Hydrogen sulfide (H2S) is a prominent EDRF, since mice lacking its biosynthetic enzyme, cystathionine γ-lyase (CSE), display pronounced hypertension with deficient vasorelaxant responses to acetylcholine. Objective The purpose of this study is to determine if H2S is a major physiologic EDHF. Methods and Results We now show that H2S is a major EDHF, as in blood vessels of CSE deleted mice hyperpolarization is virtually abolished. H2S acts by covalently modifying (sulfhydrating) the ATP-sensitive potassium channel, as mutating the site of sulfhydration prevents H2S-elicited hyperpolarization. The endothelial intermediate conductance (IKCa) and small conductance (SKCa) potassium channels mediate in part the effects of H2S, as selective IKCa and SKCa channel inhibitors, charybdotoxin and apamin, inhibit glibenclamide insensitive H2S induced vasorelaxation. Conclusions H2S is a major EDHF that causes vascular endothelial and smooth muscle cell hyperpolarization and vasorelaxation by activating the ATP-sensitive, intermediate conductance and small conductance potassium channels through cysteine S-sulfhydration. As EDHF activity is a principal determinant of vasorelaxation in numerous vascular beds, drugs influencing H2S biosynthesis offer therapeutic potential. PMID:21980127

  6. Role of Hydrogen Sulfide in the Physiology of Penile Erection

    PubMed Central

    Qiu, Xuefeng; Villalta, Jackie; Lin, Guiting; Lue, Tom F.

    2012-01-01

    Hydrogen sulfide (H2S), which is a well known toxic gas, has recently been recognized as a biological messenger, which plays an important role in physiological and pathophysiological conditions. Relatively high levels of H2S have been discovered in mammalian tissues. It is mainly synthesized by two enzymes including cystathionine β-synthase and cystathionine γ-lysase, which utilize L-cysteine as substrate to produce H2S. H2S has been demonstrated to exhibit potent vasodilator activity both in vitro and in vivo by relaxing vascular smooth muscle. Recently, H2S has been discovered in penile tissue with smooth muscle relaxant effects. Furthermore, other effects of H2S may play a role in the physiology of erection. Understanding of H2S in the physiology of erection might provide alternative erectile dysfunction (ED) strategies for those patients with poor or no response to type 5 phosphodiesterase inhibitors (PDE5i). This review intends to present the H2S pathway in penile tissue and the potential role of H2S in the physiology of erections. PMID:22016355

  7. Increasing prevalence of hydrogen sulfide negative Salmonella in retail meats.

    PubMed

    Lin, Dachuan; Yan, Meiying; Lin, Song; Chen, Sheng

    2014-10-01

    Hydrogen sulfide (H2S) production is considered a typical characteristic of Salmonella and an important marker for Salmonella isolation. In this study, a total of 82 (26%) Salmonella strains were isolated from 113 chicken and 204 pork samples, within which 49 Salmonella strains were H2S positive and 33 were H2S negative. Salmonella enterica serovar Derby was most prevalent in both pork and chicken followed by S. Typhimurium in pork and S. Heidelberg in chicken. Salmonella isolated from pork exhibited a much higher H2S positive rate than those from chicken (68% versus 31%). The most prevalent H2S negative serotypes were S. Derby (40%) and S. Heidelberg (30%) in chicken, and S. Typhimurium (23%) and S. Enteritidis (23%) in pork. spvC, a plasmid-encoded virulence marker, was detected in 51% and 42% of the H2S positive and negative Salmonella respectively. The presence of the two most important serotypes, S. Enteritidis and S. Typhimurium, as well as a virulence plasmid in H2S negative Salmonella suggested that H2S negative Salmonella is also a significant public health concern. Such finding warrants the development of an improved method for effective coverage of H2S negative Salmonella.

  8. Determination of Hydrogen Sulfide in Fermentation Broths Containing SO21

    PubMed Central

    Acree, T. E.; Sonoff, Elisabeth P.; Splittstoesser, D. F.

    1971-01-01

    A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 μg of SO2 per ml is described. The method involves the sparging of H2S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO2 with the analysis. PMID:5111300

  9. Vertebrate phylogeny of hydrogen sulfide vasoactivity.

    PubMed

    Dombkowski, Ryan A; Russell, Michael J; Schulman, Alexis A; Doellman, Meredith M; Olson, Kenneth R

    2005-01-01

    Hydrogen sulfide (H(2)S) is a recently identified endogenous vasodilator in mammals. In steelhead/rainbow trout (Oncorhynchus mykiss, Osteichthyes), H(2)S produces both dose-dependent dilation and a unique dose-dependent constriction. In this study, we examined H(2)S vasoactivity in all vertebrate classes to determine whether H(2)S is universally vasoactive and to identify phylogenetic and/or environmental trends. H(2)S was generated from NaHS and examined in unstimulated and precontracted systemic and, when applicable, pulmonary arteries (PA) from Pacific hagfish (Eptatretus stouti, Agnatha), sea lamprey (Petromyzon marinus, Agnatha), sandbar shark (Carcharhinus milberti, Chondrichthyes), marine toad (Bufo marinus, Amphibia), American alligator (Alligator mississippiensis, Reptilia), Pekin duck (Anas platyrhynchos domesticus, Aves), and white rat (Rattus rattus, Mammalia). In otherwise unstimulated vessels, NaHS produced 1) a dose-dependent relaxation in Pacific hagfish dorsal aorta; 2) a dose-dependent contraction in sea lamprey dorsal aorta, marine toad aorta, alligator aorta and PA, duck aorta, and rat thoracic aorta; 3) a threshold relaxation in shark ventral aorta, dorsal aorta, and afferent branchial artery; and 4) a multiphasic contraction-relaxation-contraction in the marine toad PA, duck PA, and rat PA. Precontraction of these vessels with another agonist did not affect the general pattern of NaHS vasoactivity with the exception of the rat aorta, where relaxation was now dominant. These results show that H(2)S is a phylogenetically ancient and versatile vasoregulatory molecule that appears to have been opportunistically engaged to suit both organ-specific and species-specific homeostatic requirements.

  10. Working with "H2S": facts and apparent artifacts.

    PubMed

    Wedmann, Rudolf; Bertlein, Sarah; Macinkovic, Igor; Böltz, Sebastian; Miljkovic, Jan Lj; Muñoz, Luis E; Herrmann, Martin; Filipovic, Milos R

    2014-09-15

    Hydrogen sulfide (H2S) is an important signaling molecule with physiological endpoints similar to those of nitric oxide (NO). Growing interest in its physiological roles and pharmacological potential has led to large sets of contradictory data. The principle cause of these discrepancies can be the common neglect of some of the basic H2S chemistry. This study investigates how the experimental outcome when working with H2S depends on its source and dose and the methodology employed. We show that commercially available NaHS should be avoided and that traces of metal ions should be removed because these can reduce intramolecular disulfides and change protein structure. Furthermore, high H2S concentrations may lead to a complete inhibition of cell respiration, mitochondrial membrane potential depolarization and superoxide generation, which should be considered when discussing the biological effects observed upon treatment with high concentrations of H2S. In addition, we provide chemical evidence that H2S can directly react with superoxide. H2S is also capable of reducing cytochrome c(3+) with the concomitant formation of superoxide. H2S does not directly react with nitrite but with NO electrodes that detect H2S. In addition, H2S interferes with the Griess reaction and should therefore be removed from the solution by Cd(2+) or Zn(2+) precipitation prior to nitrite quantification. 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) is reduced by H2S, and its use should be avoided in combination with H2S. All these constraints must be taken into account when working with H2S to ensure valid data.

  11. The response of Caenorhabditis elegans to hydrogen sulfide and hydrogen cyanide.

    PubMed

    Budde, Mark W; Roth, Mark B

    2011-10-01

    Hydrogen sulfide (H2S), an endogenously produced small molecule, protects animals from various stresses. Recent studies demonstrate that animals exposed to H2S are long lived, resistant to hypoxia, and resistant to ischemia-reperfusion injury. We performed a forward genetic screen to gain insights into the molecular mechanisms Caenorhabditis elegans uses to appropriately respond to H2S. At least two distinct pathways appear to be important for this response, including the H2S-oxidation pathway and the hydrogen cyanide (HCN)-assimilation pathway. The H2S-oxidation pathway requires two distinct enzymes important for the oxidation of H2S: the sulfide:quinone reductase sqrd-1 and the dioxygenase ethe-1. The HCN-assimilation pathway requires the cysteine synthase homologs cysl-1 and cysl-2. A low dose of either H2S or HCN can activate hypoxia-inducible factor 1 (HIF-1), which is required for C. elegans to respond to either gas. sqrd-1 and cysl-2 represent the entry points in the H2S-oxidation and HCN-assimilation pathways, respectively, and expression of both of these enzymes is highly induced by HIF-1 in response to both H2S and HCN. In addition to their role in appropriately responding to H2S and HCN, we found that cysl-1 and cysl-2 are both essential mediators of innate immunity against fast paralytic killing by Pseudomonas. Furthermore, in agreement with these data, we showed that growing worms in the presence of H2S is sufficient to confer resistance to Pseudomonas fast paralytic killing. Our results suggest the hypoxia-independent hif-1 response in C. elegans evolved to respond to the naturally occurring small molecules H2S and HCN.

  12. Redox biochemistry of hydrogen sulfide.

    PubMed

    Kabil, Omer; Banerjee, Ruma

    2010-07-16

    H(2)S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of gamma-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H(2)S production in the vasculature. However, patients with inherited deficiency in gamma-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxidative phosphorylation while also exposing cytochrome c oxidase to this metabolic poison. This report focuses on the biochemistry of H(2)S biogenesis and clearance, on the molecular mechanisms of its action, and on its varied biological effects.

  13. H2S and Blood Vessels: An Overview.

    PubMed

    Yang, Guangdong; Wang, Rui

    2015-01-01

    The physiological and biomedical importance of hydrogen sulfide (H2S) has been fully recognized in the cardiovascular system as well as in the rest of the body. In blood vessels, cystathionine γ-lyase (CSE) is a major H2S-producing enzyme expressed in both smooth muscle and endothelium as well as periadventitial adipose tissues. Regulation of H2S production from CSE is controlled by a complex integration of transcriptional, posttranscriptional, and posttranslational mechanisms in blood vessels. In smooth muscle cells, H2S regulates cell apoptosis, phenotypic switch, relaxation and contraction, and calcification. In endothelial cells, H2S controls cell proliferation, cellular senescence, oxidative stress, inflammation, etc. H2S interacts with nitric oxide and acts as an endothelium-derived relaxing factor and an endothelium-derived hyperpolarizing factor. H2S generated from periadventitial adipose tissues acts as an adipocyte-derived relaxing factor and modulates the vascular tone. Extensive evidence has demonstrated the beneficial roles of the CSE/H2S system in various blood vessel diseases, such as hypertension, atherosclerosis, and aortic aneurysm. The important roles signaling in the cardiovascular system merit further intensive and extensive investigation. H2S-releasing agents and CSE activators will find their great applications in the prevention and treatment of blood vessel-related disorders.

  14. Analytical Measurement of Discrete Hydrogen Sulfide Pools in Biological Specimens

    PubMed Central

    Shen, Xinggui; Peter, Elvis A.; Bir, Shyamal; Wang, Rui; Kevil, Christopher G.

    2015-01-01

    Hydrogen sulfide (H2S) is a ubiquitous gaseous signaling molecule that plays a vital role in numerous cellular functions and has become the focus of many research endeavors including pharmaco-therapeutic manipulation. Amongst the challenges facing the field is the accurate measurement of biologically active H2S. We have recently reported that the typically used methylene blue method and its associated results are invalid and do not measure bonafide H2S. The complexity of analytical H2S measurement reflects the fact that hydrogen sulfide is a volatile gas and exists in the body in different forms, including a free form, an acid labile pool and as bound sulfane sulfur. Here we describe a new protocol to discretely measure specific H2S pools using the monobromobimane method coupled with RP-HPLC. This new protocol involves selective liberation, trapping and derivatization of H2S. Acid-labile H2S is released by incubating the sample in an acidic solution (pH 2.6) of 100 mM phosphate buffer with 0.1 mM DTPA, in an enclosed system to contain volatilized H2S. Volatilized H2S is then trapped in 100 mM Tris-HCl (pH 9.5, 0.1 mM DTPA) and then reacted with excess monobromobimane. In a separate aliquot, the contribution of bound sulfane sulfur pool was measured by incubating the sample with 1 mM TCEP (Tris(2-carboxyethyl)phosphine hydrochloride), a reducing agent to reduce disulfide bonds, in 100 mM phosphate buffer (pH 2.6, 0.1 mM DTPA), and H2S measurement performed in an analogous manner to the one described above. The acid labile pool was determined by subtracting the free hydrogen sulfide value from the value obtained by the acid liberation protocol. The bound sulfane sulfur pool was determined by subtracting the H2S measurement from the acid liberation protocol alone compared to that of TCEP plus acidic conditions. In summary, our new method protocol allows very sensitive and accurate measurement of the three primary biological pools of H2S including free, acid labile

  15. Design and synthesis of polymeric hydrogen sulfide donors.

    PubMed

    Hasegawa, Urara; van der Vlies, André J

    2014-07-16

    Hydrogen sulfide (H2S) is a gaseous signaling molecule that has several important biological functions in the human body. Because of the difficulties of handling H2S gas, small organic compounds that release H2S under physiological conditions have been developed. The observed bioactivities of these H2S donors have generally been directly correlated with their H2S release properties. However, apart from H2S release, these H2S donors also exert biological effects by direct interaction with intracellular components within the cytoplasm after passive diffusion across cellular membranes. Here we report polymeric H2S donors based on ADT-OH which would alter cellular trafficking of ADT-OH to minimize the unfavorable interactions with intracellular components. We designed and synthesized a poly(ethylene glycol)-ADT (PEG-ADT) conjugate having ADT linked via an ether bond. Whereas ADT-OH significantly reduced cell viability in murine macrophages, the PEG-ADT conjugate did not show obvious cytotoxicity. The PEG-ADT conjugate released H2S in murine macrophages but not in the presence of serum proteins. The PEG-ADT conjugate was taken up by the cell through the endocytic pathway and stayed inside endolysosomes, which is different from the small amphiphilic donor ADT-OH that can directly enter the cytoplasm. Furthermore, PEG-ADT was capable of potentiating LPS-induced inflammation. This polymeric H2S donor approach may help to better understand the H2S bioactivities of the H2S donor ADT-OH.

  16. Thioethers as markers of hydrogen sulfide production in homocystinurias.

    PubMed

    Kožich, Viktor; Krijt, Jakub; Sokolová, Jitka; Melenovská, Petra; Ješina, Pavel; Vozdek, Roman; Majtán, Tomáš; Kraus, Jan P

    2016-07-01

    Two enzymes in the transsulfuration pathway of homocysteine -cystathionine beta-synthase (CBS) and gamma-cystathionase (CTH)-use cysteine and/or homocysteine to produce the important signaling molecule hydrogen sulfide (H2S) and simultaneously the thioethers lanthionine, cystathionine or homolanthionine. In this study we explored whether impaired flux of substrates for H2S synthesis and/or deficient enzyme activities alter production of hydrogen sulfide in patients with homocystinurias. As an indirect measure of H2S synthesis we determined by LC-MS/MS concentrations of thioethers in plasma samples from 33 patients with different types of homocystinurias, in 8 patient derived fibroblast cell lines, and as reaction products of seven purified mutant CBS enzymes. Since chaperoned recombinant mutant CBS enzymes retained capacity of H2S synthesis in vitro it can be stipulated that deficient CBS activity in vivo may impair H2S production. Indeed, in patients with classical homocystinuria we observed significantly decreased cystathionine and lanthionine concentrations in plasma (46% and 74% of median control levels, respectively) and significantly lower cystathionine in fibroblasts (8% of median control concentrations) indicating that H2S production from cysteine and homocysteine may be also impaired. In contrast, the grossly elevated plasma levels of homolanthionine in CBS deficient patients (32-times elevation compared to median of controls) clearly demonstrates a simultaneous overproduction of H2S from homocysteine by CTH. In the remethylation defects the accumulation of homocysteine and the increased flux of metabolites through the transsulfuration pathway resulted in elevation of cystathionine and homolanthionine (857% and 400% of median control values, respectively) indicating a possibility of an increased biosynthesis of H2S by both CBS and CTH. This study shows clearly disturbed thioether concentrations in homocystinurias, and modeling using these data indicates

  17. Inhibition of Mitochondrial Bioenergetics by Esterase-Triggered COS/H2S Donors.

    PubMed

    Steiger, Andrea K; Marcatti, Michela; Szabo, Csaba; Szczesny, Bartosz; Pluth, Michael D

    2017-08-18

    Hydrogen sulfide (H2S) is an important biological mediator, and synthetic H2S donating molecules provide an important class of investigative tools for H2S research. Here, we report esterase-activated H2S donors that function by first releasing carbonyl sulfide (COS), which is rapidly converted to H2S by the ubiquitous enzyme carbonic anhydrase (CA). We report the synthesis, self-immolative decomposition, and H2S release profiles of the developed scaffolds. In addition, the developed esterase-triggered COS/H2S donors exhibit higher levels of cytotoxicity than equivalent levels of Na2S or the common H2S donors GYY4137 and AP39. Using cellular bioenergetics measurements, we establish that the developed donors reduce cellular respiration and ATP synthesis in BEAS 2B human lung epithelial cells, which is consistent with COS/H2S inhibition of cytochrome c oxidase in the mitochondrial respiratory chain although not observed with common H2S donors at the same concentrations. Taken together, these results may suggest that COS functions differently than H2S in certain biological contexts or that the developed donors are more efficient at delivering H2S than other common H2S-releasing motifs.

  18. Physiological Importance of Hydrogen Sulfide: Emerging Potent Neuroprotector and Neuromodulator

    PubMed Central

    Chung, Hyung-Joo

    2016-01-01

    Hydrogen sulfide (H2S) is an emerging neuromodulator that is considered to be a gasotransmitter similar to nitrogen oxide (NO) and carbon monoxide (CO). H2S exerts universal cytoprotective effects and acts as a defense mechanism in organisms ranging from bacteria to mammals. It is produced by the enzymes cystathionine β-synthase (CBS), cystathionine ϒ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (MST), and D-amino acid oxidase (DAO), which are also involved in tissue-specific biochemical pathways for H2S production in the human body. H2S exerts a wide range of pathological and physiological functions in the human body, from endocrine system and cellular longevity to hepatic protection and kidney function. Previous studies have shown that H2S plays important roles in peripheral nerve regeneration and degeneration and has significant value during Schwann cell dedifferentiation and proliferation but it is also associated with axonal degradation and the remyelination of Schwann cells. To date, physiological and toxic levels of H2S in the human body remain unclear and most of the mechanisms of action underlying the effects of H2S have yet to be fully elucidated. The primary purpose of this review was to provide an overview of the role of H2S in the human body and to describe its beneficial effects. PMID:27413423

  19. Epithelial Electrolyte Transport Physiology and the Gasotransmitter Hydrogen Sulfide.

    PubMed

    Pouokam, Ervice; Althaus, Mike

    2016-01-01

    Hydrogen sulfide (H2S) is a well-known environmental chemical threat with an unpleasant smell of rotten eggs. Aside from the established toxic effects of high-dose H2S, research over the past decade revealed that cells endogenously produce small amounts of H2S with physiological functions. H2S has therefore been classified as a "gasotransmitter." A major challenge for cells and tissues is the maintenance of low physiological concentrations of H2S in order to prevent potential toxicity. Epithelia of the respiratory and gastrointestinal tract are especially faced with this problem, since these barriers are predominantly exposed to exogenous H2S from environmental sources or sulfur-metabolising microbiota. In this paper, we review the cellular mechanisms by which epithelial cells maintain physiological, endogenous H2S concentrations. Furthermore, we suggest a concept by which epithelia use their electrolyte and liquid transport machinery as defence mechanisms in order to eliminate exogenous sources for potentially harmful H2S concentrations.

  20. Physiological and pharmacological features of the novel gasotransmitter: Hydrogen sulfide

    PubMed Central

    Mancardi, Daniele; Penna, Claudia; Merlino, Annalisa; Del Soldato, Piero; Wink, David A.; Pagliaro, Pasquale

    2012-01-01

    Hydrogen sulfide (H2S) has been known for hundreds of years because of its poisoning effect. Once the basal bio-production became evident its pathophysiological role started to be investigated in depth. H2S is a gas that can be formed by the action of two enzymes, cystathionine gamma-lyase and cystathionine beta-synthase, both involved in the metabolism of cysteine. It has several features in common with the other two well known “gasotransmitters” (nitric oxide and carbon monoxide) in the biological systems. These three gasses share some biological targets; however, they also have dissimilarities. For instance, the three gases target heme-proteins and open KATP channels; H2S as NO is an antioxidant, but in contrast to the latter molecule, H2S does not directly form radicals. In the last years H2S has been implicated in several physiological and pathophysiological processes such as long term synaptic potentiation, vasorelaxation, pro- and anti-inflammatory conditions, cardiac inotropism regulation, cardioprotection, and several other physiological mechanisms. We will focus on the biological role of H2S as a molecule able to trigger cell signaling. Our attention will be particularly devoted on the effects in cardiovascular system and in cardioprotection. We will also provide available information on H2S-donating drugs which have so far been tested in order to conjugate the beneficial effect of H2S with other pharmaceutical properties. PMID:19285949

  1. Epithelial Electrolyte Transport Physiology and the Gasotransmitter Hydrogen Sulfide

    PubMed Central

    Pouokam, Ervice; Althaus, Mike

    2016-01-01

    Hydrogen sulfide (H2S) is a well-known environmental chemical threat with an unpleasant smell of rotten eggs. Aside from the established toxic effects of high-dose H2S, research over the past decade revealed that cells endogenously produce small amounts of H2S with physiological functions. H2S has therefore been classified as a “gasotransmitter.” A major challenge for cells and tissues is the maintenance of low physiological concentrations of H2S in order to prevent potential toxicity. Epithelia of the respiratory and gastrointestinal tract are especially faced with this problem, since these barriers are predominantly exposed to exogenous H2S from environmental sources or sulfur-metabolising microbiota. In this paper, we review the cellular mechanisms by which epithelial cells maintain physiological, endogenous H2S concentrations. Furthermore, we suggest a concept by which epithelia use their electrolyte and liquid transport machinery as defence mechanisms in order to eliminate exogenous sources for potentially harmful H2S concentrations. PMID:26904165

  2. Carbamoylation abrogates the antioxidant potential of hydrogen sulfide.

    PubMed

    Praschberger, Monika; Hermann, Marcela; Laggner, Christian; Jirovetz, Leopold; Exner, Markus; Kapiotis, Stylianos; Gmeiner, Bernhard M K; Laggner, Hilde

    2013-11-01

    Hydrogen sulfide (H2S) has been identified as the third gasotransmitter. Beside its role as signaling molecule in the cardiovascular and nervous system the antioxidant and cyto-protective properties of H2S have gained much attention. In the present study we show that cyanate, an uremic toxin which is found in abundant concentration in sera of patients suffering from chronic kidney disease (CKD), can abrogate the antioxidant and cytoprotective activity of H2S via S-carbamoylation reaction, a reaction that previously has only been shown to have a physiological effect on cysteine groups, but not on H2S. Carbamoylation strongly inhibited the free radical scavenging (ABTS(+·) and alkylperoxyl ROO(·)) properties of H2S. The extent of intracellular ROS formation induced by ROO(·) was diminished by H2S whereas carbamoylation counteracted the protective effect. Reagent HOCl was rapidly inactivated by H2S in contrast to the carbamoylated compound. Protein modification by HOCl was inhibited by H2S but carbamoylation significantly reduced the effect. Thus, S-carbamoylation of low molecular weight thiols by abrogating their antioxidant potential may contribute to the higher oxidative stress observed in CKD.

  3. Polysulfides Link H2S to Protein Thiol Oxidation

    PubMed Central

    Greiner, Romy; Pálinkás, Zoltán; Bäsell, Katrin; Becher, Dörte; Antelmann, Haike; Nagy, Péter

    2013-01-01

    Abstract Aims: Hydrogen sulfide (H2S) is suggested to act as a gaseous signaling molecule in a variety of physiological processes. Its molecular mechanism of action was proposed to involve protein S-sulfhydration, that is, conversion of cysteinyl thiolates (Cys-S−) to persulfides (Cys-S-S−). A central and unresolved question is how H2S—that is, a molecule with sulfur in its lowest possible oxidation state (−2)—can lead to oxidative thiol modifications. Results: Using the lipid phosphatase PTEN as a model protein, we find that the “H2S donor” sodium hydrosulfide (NaHS) leads to very rapid reversible oxidation of the enzyme in vitro. We identify polysulfides formed in NaHS solutions as the oxidizing species, and present evidence that sulfane sulfur is added to the active site cysteine. Polysulfide-mediated oxidation of PTEN was induced by all “H2S donors” tested, including sodium sulfide (Na2S), gaseous H2S, and morpholin-4-ium 4-methoxyphenyl(morpholino) phosphinodithioate (GYY4137). Moreover, we show that polysulfides formed in H2S solutions readily modify PTEN inside intact cells. Innovation: Our results shed light on the previously unresolved question of how H2S leads to protein thiol oxidation, and suggest that polysulfides formed in solutions of H2S mediate this process. Conclusion: This study suggests that the effects that have been attributed to H2S in previous reports may in fact have been mediated by polysulfides. It also supports the notion that sulfane sulfur rather than sulfide is the actual in vivo agent of H2S signaling. Antioxid. Redox Signal. 19, 1749–1765. PMID:23646934

  4. Hydrogen sulfide on Io - Evidence from telescopic and laboratory infrared spectra

    NASA Technical Reports Server (NTRS)

    Nash, Douglas B.; Howell, Robert R.

    1989-01-01

    Evidence is reported for hydrogen sulfide on Io's surface. An infrared band at 3.915 (+ or - 0.015) micrometers in several ground-based spectra of Io can be accounted for by reflectance from H2S frost deposited on or cocondensed with sulfur dioxide frost. Temporal variation in the occurrence and intensity of the band suggests that condensed H2S on Io's surface is transient, implying a similar variation of H2S abundance in Io's atmosphere.

  5. A fatality caused by accidental production of hydrogen sulfide.

    PubMed

    Chaturvedi, A K; Smith, D R; Canfield, D V

    2001-12-01

    A 55-year-old male Caucasian truck driver was dead at the scene after breathing hydrogen sulfide (H(2)S) produced by an accidental transfer of sodium hydrogen sulfide (NaHS) from a tanker truck to a tank containing 4% sulfuric acid (H(2)SO(4)) and iron(II) sulfate (FeSO(4)). Autopsy of the decedent's body revealed pulmonary edema and passive congestion in lungs, spleen, kidneys, and adrenal glands. Postmortem biological samples were analyzed for carbon monoxide, cyanide, ethanol, and drugs. Since a potential exposure to H(2)S was involved, blood was also analyzed for sulfide (S(2-)). The analysis entailed isolating S(2-) from blood as H(2)S using 0.5M H(3)PO(4), trapping the gas in 0.1M NaOH, and determining the electromotive force using a sulfide ion specific electrode. Acetaminophen at a concentration of 14.3 microg/ml was found in blood, and metoprolol was detected in the blood, liver, and kidney samples. The blood S(2-) level was determined to be 1.68 microg/ml. It is concluded that the cause of death was H(2)S poisoning associated with a hazardous material accident in an industrial situation.

  6. Enhanced hydrogen oxidation activity and H2S tolerance of Ni-infiltrated ceria solid oxide fuel cell anodes

    NASA Astrophysics Data System (ADS)

    Mirfakhraei, Behzad; Paulson, Scott; Thangadurai, Venkataraman; Birss, Viola

    2013-12-01

    The effect of Ni infiltration into porous Gd-doped ceria (GDC) anodes on their H2 oxidation performance, with and without added 10 ppm H2S, is reported here. Porous GDC anodes (ca. 10 μm thick) were deposited on yttria stabilized zirconia (YSZ) supports and then infiltrated with catalytic amounts of a Ni nitrate solution, followed by electrochemical testing in a 3-electrode half-cell setup at 500-800 °C. Infiltration of 3 wt.% Ni into the porous GDC anode lowered the polarization resistance by up to 85%, affecting mainly the low frequency impedance arc. When exposed to 10 ppm H2S, the Ni-infiltrated anodes exhibited a ca. 5 times higher tolerance toward sulfur poisoning compared to GDC anodes alone, also showing excellent long-term stability in 10 ppm H2S. In the presence of H2S, it is proposed that Ni, likely distributed as a nanophase, helps to maintain a clean GDC surface at the Ni/GDC interface at which the H2 oxidation reaction takes place. In turn, the GDC will readily supply oxygen anions to the adjacent Ni surfaces, thus helping to remove adsorbed sulfur.

  7. Chronic Ambient Hydrogen Sulfide Exposure and Cognitive Function

    PubMed Central

    Reed, Bruce R.; Crane, Julian; Garrett, Nick; Woods, David L.; Bates, Michael N.

    2014-01-01

    Background Exposures to hydrogen sulfide gas (H2S) have been inconclusively linked to a variety of negative cognitive outcomes. We investigated possible effects on cognitive function in an urban population with chronic, low-level exposure to H2S. Methods Participants were 1,637 adults, aged 18-65 years from Rotorua city, New Zealand, exposed to ambient H2S from geothermal sources. Exposures at homes and workplaces were estimated from data collected by summer and winter H2S monitoring networks across Rotorua in 2010/11. Metrics for H2S exposure at the time of participation and for exposure over the last 30 years were calculated. H2S exposure was modeled both as continuous variables and as quartiles of exposure covering the range of 0 – 64 ppb (0-88 μg/m3). Outcomes were neuropsychological tests measuring visual and verbal episodic memory, attention, fine motor skills, psychomotor speed and mood. Associations between cognition and measures of H2S exposure were investigated with multiple regression, while covarying demographics and factors known to be associated with cognitive performance. Results The consistent finding was of no association between H2S exposure and cognition. Quartiles of H2S exposure had a small association with simple reaction time: higher exposures were associated with faster response times. Similarly, for digit symbol, higher H2S exposures tended to be marginally associated with better performance. Conclusion The results provide evidence that chronic H2S exposure, at the ambient levels found in and around Rotorua, is not associated with impairment of cognitive function. PMID:24548790

  8. Chronic ambient hydrogen sulfide exposure and cognitive function.

    PubMed

    Reed, Bruce R; Crane, Julian; Garrett, Nick; Woods, David L; Bates, Michael N

    2014-01-01

    Exposures to hydrogen sulfide gas (H2S) have been inconclusively linked to a variety of negative cognitive outcomes. We investigated possible effects on cognitive function in an urban population with chronic, low-level exposure to H2S. Participants were 1637 adults, aged 18-65 years from Rotorua city, New Zealand, exposed to ambient H2S from geothermal sources. Exposures at homes and workplaces were estimated from data collected by summer and winter H2S monitoring networks across Rotorua in 2010/11. Metrics for H2S exposure at the time of participation and for exposure over the last 30 years were calculated. H2S exposure was modeled both as continuous variables and as quartiles of exposure covering the range of 0-64 ppb (0-88 μg/m(3)). Outcomes were neuropsychological tests measuring visual and verbal episodic memory, attention, fine motor skills, psychomotor speed and mood. Associations between cognition and measures of H2S exposure were investigated with multiple regression, while covarying demographics and factors known to be associated with cognitive performance. The consistent finding was of no association between H2S exposure and cognition. Quartiles of H2S exposure had a small association with simple reaction time: higher exposures were associated with faster response times. Similarly, for digit symbol, higher H2S exposures tended to be marginally associated with better performance. The results provide evidence that chronic H2S exposure, at the ambient levels found in and around Rotorua, is not associated with impairment of cognitive function. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Is hydrogen sulfide-induced suspended animation general anesthesia?

    PubMed

    Li, Rosie Q; McKinstry, Andrew R; Moore, Jason T; Caltagarone, Breanna M; Eckenhoff, Maryellen F; Eckenhoff, Roderic G; Kelz, Max B

    2012-06-01

    Hydrogen sulfide (H(2)S) depresses mitochondrial function and thereby metabolic rates in mice, purportedly resulting in a state of "suspended animation." Volatile anesthetics also depress mitochondrial function, an effect that may contribute to their anesthetic properties. In this study, we ask whether H(2)S has general anesthetic properties, and by extension, whether mitochondrial effects underlie the state of anesthesia. We compared loss of righting reflex, electroencephalography, and electromyography in mice exposed to metabolically equipotent concentrations of halothane, isoflurane, sevoflurane, and H(2)S. We also studied combinations of H(2)S and anesthetics to assess additivity. Finally, the long-term effects of H(2)S were assessed by using the Morris water maze behavioral testing 2 to 3 weeks after exposures. Exposure to H(2)S decreases O(2) consumption, CO(2) production, and body temperature similarly to that of the general anesthetics, but fails to produce a loss of righting reflex or muscle atonia at metabolically equivalent concentrations. When combined, H(2)S antagonizes the metabolic effects of isoflurane, but potentiates the isoflurane-induced loss of righting reflex. We found no effect of prior H(2)S exposure on memory or learning. H(2)S (250 ppm), not itself lethal, produced delayed lethality when combined with subanesthetic concentrations of isoflurane. H(2)S cannot be considered a general anesthetic, despite similar metabolic suppression. Metabolic suppression, presumably via mitochondrial actions, is not sufficient to account for the hypnotic or immobilizing components of the anesthetic state. Combinations of H(2)S and isoflurane can be lethal, suggesting extreme care in the combination of these gases in clinical situations.

  10. Working with nitric oxide and hydrogen sulfide in biological systems

    PubMed Central

    Yuan, Shuai; Kevil, Christopher G.

    2014-01-01

    Nitric oxide (NO) and hydrogen sulfide (H2S) are gasotransmitter molecules important in numerous physiological and pathological processes. Although these molecules were first known as environmental toxicants, it is now evident that that they are intricately involved in diverse cellular functions with impact on numerous physiological and pathogenic processes. NO and H2S share some common characteristics but also have unique chemical properties that suggest potential complementary interactions between the two in affecting cellular biochemistry and metabolism. Central among these is the interactions between NO, H2S, and thiols that constitute new ways to regulate protein function, signaling, and cellular responses. In this review, we discuss fundamental biochemical principals, molecular functions, measurement methods, and the pathophysiological relevance of NO and H2S. PMID:25550314

  11. Fluorescent probes for hydrogen sulfide detection and bioimaging.

    PubMed

    Yu, Fabiao; Han, Xiaoyue; Chen, Lingxin

    2014-10-21

    In comparison with other biological detection technologies, fluorescence bioimaging technology has become a powerful supporting tool for intracellular detection, and can provide attractive facilities for investigating physiological and pathological processes of interest with high spatial and temporal resolution, less invasiveness, and a rapid response. Due to the versatile roles of hydrogen sulfide (H2S) in cellular signal transduction and intracellular redox status regulation, fluorescent probes for the detection of this third signalling gasotransmitter have rapidly increased in number in recent years. These probes can offer powerful means to investigate the physiological actions of H2S in its native environments without disturbing its endogenous distribution. In this feature article, we address the synthesis and design strategies for the development of fluorescent probes for H2S based on the reaction type between H2S and the probes. Moreover, we also highlight fluorescent probes for other reactive sulfur species, such as sulfane sulfurs and SO2 derivatives.

  12. A practical guide to working with H2S at the interface of chemistry and biology.

    PubMed

    Hartle, Matthew D; Pluth, Michael D

    2016-11-07

    Hydrogen sulfide (H2S) is the most recently accepted endogenously produced gasotransmitter and is now implicated in a variety of physiological functions. In this tutorial review, our goal is to provide researchers new to the field of H2S chemical biology with practical considerations, pitfalls, and best practices to enable smooth entry into investigations focused on biological H2S. We present practical handling and safety considerations for working with this reactive biomolecule, and cover basic roles of H2S biogenesis and action. Experimental methods for modulating H2S levels, including enzymatic knockout, RNA silencing, enzymatic inhibition, and use of small molecule H2S donors are highlighted. Complementing H2S modulation techniques, we also highlight current strategies for H2S detection and quantification.

  13. The metallization and superconductivity of dense hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Li, Yinwei; Hao, Jian; Liu, Hanyu; Li, Yanling; Ma, Yanming

    2014-05-01

    Hydrogen sulfide (H2S) is a prototype molecular system and a sister molecule of water (H2O). The phase diagram of solid H2S at high pressures remains largely unexplored arising from the challenges in dealing with the pressure-induced weakening of S-H bond and larger atomic core difference between H and S. Metallization is yet achieved for H2O, but it was observed for H2S above 96 GPa. However, the metallic structure of H2S remains elusive, greatly impeding the understanding of its metallicity and the potential superconductivity. We have performed an extensive structural study on solid H2S at pressure ranges of 10-200 GPa through an unbiased structure prediction method based on particle swarm optimization algorithm. Besides the findings of candidate structures for nonmetallic phases IV and V, we are able to establish stable metallic structures violating an earlier proposal of elemental decomposition into sulfur and hydrogen [R. Rousseau, M. Boero, M. Bernasconi, M. Parrinello, and K. Terakura, Phys. Rev. Lett. 85, 1254 (2000)]. Our study unravels a superconductive potential of metallic H2S with an estimated maximal transition temperature of ˜80 K at 160 GPa, higher than those predicted for most archetypal hydrogen-containing compounds (e.g., SiH4, GeH4, etc.).

  14. The metallization and superconductivity of dense hydrogen sulfide.

    PubMed

    Li, Yinwei; Hao, Jian; Liu, Hanyu; Li, Yanling; Ma, Yanming

    2014-05-07

    Hydrogen sulfide (H2S) is a prototype molecular system and a sister molecule of water (H2O). The phase diagram of solid H2S at high pressures remains largely unexplored arising from the challenges in dealing with the pressure-induced weakening of S-H bond and larger atomic core difference between H and S. Metallization is yet achieved for H2O, but it was observed for H2S above 96 GPa. However, the metallic structure of H2S remains elusive, greatly impeding the understanding of its metallicity and the potential superconductivity. We have performed an extensive structural study on solid H2S at pressure ranges of 10-200 GPa through an unbiased structure prediction method based on particle swarm optimization algorithm. Besides the findings of candidate structures for nonmetallic phases IV and V, we are able to establish stable metallic structures violating an earlier proposal of elemental decomposition into sulfur and hydrogen [R. Rousseau, M. Boero, M. Bernasconi, M. Parrinello, and K. Terakura, Phys. Rev. Lett. 85, 1254 (2000)]. Our study unravels a superconductive potential of metallic H2S with an estimated maximal transition temperature of ∼80 K at 160 GPa, higher than those predicted for most archetypal hydrogen-containing compounds (e.g., SiH4, GeH4, etc.).

  15. Solubility and Permeation of Hydrogen Sulfide in Lipid Membranes

    PubMed Central

    Cuevasanta, Ernesto; Denicola, Ana; Alvarez, Beatriz; Möller, Matías N.

    2012-01-01

    Hydrogen sulfide (H2S) is mainly known for its toxicity but has recently been shown to be produced endogenously in mammalian tissues and to be associated with physiological regulatory functions. To better understand the role of biomembranes in modulating its biological distribution and effects; we measured the partition coefficient of H2S in models of biological membranes. The partition coefficients were found to be 2.1±0.2, 1.9±0.5 and 2.0±0.6 in n-octanol, hexane and dilauroylphosphatidylcholine liposome membranes relative to water, respectively (25°C). This two-fold higher concentration of H2S in the membrane translates into a rapid membrane permeability, Pm = 3 cm s−1. We used a mathematical model in three dimensions to gain insight into the diffusion of total sulfide in tissues. This model shows that the sphere of action of sulfide produced by a single cell expands to involve more than 200 neighboring cells, and that the resistance imposed by lipid membranes has a significant effect on the diffusional spread of sulfide at pH 7.4, increasing local concentrations. These results support the role of hydrogen sulfide as a paracrine signaling molecule and reveal advantageous pharmacokinetic properties for its therapeutic applications. PMID:22509322

  16. Inhaled Hydrogen Sulfide Prevents Endotoxin-Induced Systemic Inflammation and Improves Survival by Altering Sulfide Metabolism in Mice

    PubMed Central

    Tokuda, Kentaro; Kida, Kotaro; Marutani, Eizo; Crimi, Ettore; Bougaki, Masahiko; Khatri, Ashok; Kimura, Hideo

    2012-01-01

    Abstract Aims: The role of hydrogen sulfide (H2S) in endotoxin (lipopolysaccharide [LPS])-induced inflammation is incompletely understood. We examined the impact of H2S breathing on LPS-induced changes in sulfide metabolism, systemic inflammation, and survival in mice. Results: Mice that breathed air alone exhibited decreased plasma sulfide levels and poor survival rate at 72 h after LPS challenge. Endotoxemia markedly increased alanine aminotransferase (ALT) activity and nitrite/nitrate (NOx) levels in plasma and lung myeloperoxidase (MPO) activity in mice that breathed air. In contrast, breathing air supplemented with 80 ppm of H2S for 6 h after LPS challenge markedly improved survival rate compared to mice that breathed air alone (p<0.05). H2S breathing attenuated LPS-induced increase of plasma ALT activity and NOx levels and lung MPO activity. Inhaled H2S suppressed LPS-induced upregulation of inflammatory cytokines, while it markedly induced anti-inflammatory interleukin (IL)-10 in the liver. Beneficial effects of H2S inhalation after LPS challenge were associated with restored sulfide levels and markedly increased thiosulfate levels in plasma. Increased thiosulfate levels after LPS challenge were associated with upregulation of rhodanese, but not cystathionine-γ-lyase (CSE), in the liver. Administration of sodium thiosulfate dose-dependently improved survival after LPS challenge in mice. Innovation: By measuring changes in plasma levels of sulfide and sulfide metabolites using an advanced analytical method, this study revealed a critical role of thiosulfate in the protective effects of H2S breathing during endotoxemia. Conclusion: These observations suggest that H2S breathing prevents inflammation and improves survival after LPS challenge by altering sulfide metabolism in mice. Antioxid. Redox Signal. 17, 11—21. PMID:22221071

  17. H2S2014 in Kyoto: the 3rd International Conference on H2S in Biology and Medicine.

    PubMed

    Kimura, Hideo

    2015-04-30

    About 20 years ago, a pungent gas was found to be the physiological mediator of cognitive function and vascular tone. Since then, studies on hydrogen sulfide (H2S) have uncovered its numerous physiological roles such as protecting various tissues/organs from ischemia and regulating inflammation, cell growth, oxygen sensing, and senescence. These effects of H2S were extensively studied, and some of the corresponding mechanisms were also studied in detail. Previous studies on the synergistic interaction between H2S and nitric oxide (NO) have led to the discovery of several potential signaling molecules. Polysulfides are considerably potent and are one of the most active forms of H2S. H2S has a significant therapeutic potential, which is evident from the large number of novel H2S-donating compounds and substances developed for manipulating endogenous levels of H2S. The Third International Conference on H2S was held in Kyoto in June 2014. One hundred and sixty participants from 21 countries convened in Kyoto to report new advances, discuss conflicting findings, and make plans for future research. This article summarizes each oral presentation presented at the conference. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. The role of H2S bioavailability in endothelial dysfunction

    PubMed Central

    Wang, Rui; Szabo, Csaba; Ichinose, Fumito; Ahmed, Asif; Whiteman, Matthew; Papapetropoulos, Andreas

    2015-01-01

    Endothelial dysfunction reflects pathophysiological changes in the phenotype and functions of endothelial cells that result from and/or contribute to a plethora of cardiovascular diseases. Here we review the role of hydrogen sulfide (H2S) in the pathogenesis of endothelial dysfunction, one of the fastest advanced and hottest research topics. Conventionally treated as an environment pollutant, H2S is also produced in endothelial cells and participates in the fine regulation of endothelial integrity and functions. Disturbed H2S bioavailability has been suggested to be a novel indicator of the progress and prognosis of endothelial dysfunction. Endothelial dysfunction appears to exhibit in different forms in different pathologies but therapeutics aimed at remedying the altered H2S bioavailability may benefit all. PMID:26071118

  19. Endogenous production of hydrogen sulfide in isolated bovine eye.

    PubMed

    Kulkarni, Madhura; Njie-Mbye, Ya Fatou; Okpobiri, Ikechukwu; Zhao, Min; Opere, Catherine A; Ohia, Sunny E

    2011-08-01

    Hydrogen sulfide (H(2)S) is a novel gasotransmitter with physiological and pathological functions in vascular homeostasis, cardiovascular system and central nervous system. In the present study, we determined the endogenous levels of H(2)S in various tissues of the bovine eye. We also examined the basal levels of H(2)S in response to donors (sodium hydrosulfide, NaHS and sodium sulfide, Na(2)S), substrate (L: -cysteine), inhibitors (propargylglycine, PAG and aminooxyacetic acid, AOA) and activator (S-adenosyl-L: -methionine, SAM) of this gas in the bovine retina. H(2)S was measured using a well established spectrophotometric method. The highest concentration of endogenous H(2)S was detected in cornea (19 ± 2.85 nmoles/mg protein, n = 6) and retina (17 ± 2.1 nmoles/mg protein, n = 6). Interestingly, H(2)S was not present in vitreous humor. The inhibitors of CSE and CBS; PAG (1 mM) and AOA (1 mM), significantly attenuated the production of H(2)S in the bovine retina by 56.8 and 42%, respectively. On the other hand the activator of CBS; SAM (100 μM), H(2)S donors; NaHS (1 μM) and Na(2)S (100 μM), significantly increased endogenous levels of H(2)S in bovine retina. L: -cysteine (10-300 μM) produced a significant (P < 0.05) concentration-dependent increase in H(2)S levels reaching a maximal at 300 μM. We conclude that H(2)S is endogenously produced in various tissues of the isolated bovine eye. Moreover, endogenous levels of H(2)S are enhanced in the presence of substrate (L: -cysteine), an activator of CBS (SAM) and H(2)S donors but are blocked by inhibitors of enzymes that synthesize this gas in neural retina.

  20. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination

    PubMed Central

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions. PMID:27446159

  1. Chemically Reversible Reactions of Hydrogen Sulfide with Metal Phthalocyanines

    PubMed Central

    2015-01-01

    Hydrogen sulfide (H2S) is an important signaling molecule that exerts action on various bioinorganic targets. Despite this importance, few studies have investigated the differential reactivity of the physiologically relevant H2S and HS– protonation states with metal complexes. Here we report the distinct reactivity of H2S and HS– with zinc(II) and cobalt(II) phthalocyanine (Pc) complexes and highlight the chemical reversibility and cyclability of each metal. ZnPc reacts with HS–, but not H2S, to generate [ZnPc-SH]−, which can be converted back to ZnPc by protonation. CoPc reacts with HS–, but not H2S, to form [CoIPc]−, which can be reoxidized to CoPc by air. Taken together, these results demonstrate the chemically reversible reaction of HS– with metal phthalocyanine complexes and highlight the importance of H2S protonation state in understanding the reactivity profile of H2S with biologically relevant metal scaffolds. PMID:24785654

  2. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination.

    PubMed

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions.

  3. Study on Fiber-optic Hydrogen Sulfide Gas Sensor

    NASA Astrophysics Data System (ADS)

    Zhou, Hong; Wen, Jun-Qing; Zhang, Xiao-Zhen; Wang, Wei; Feng, De-Quan; Wang, Qi; Jia, Fei

    We describe a novel fiber-optic gas sensor which hydrogen Sulfide (H2S) gas can be detected by a silver coated fiber bragg grating (FBG). The H2S sensitive material Ag can be coated on the cladding surrounding surface of FBG by conventional silver mirror reaction. The scanning electron microscope (SEM) was applied to analysis the Ag film structure before and after the interaction with H2S gas. By conducting the experiment of Ag-coated optical sensor (AOS), the relation between the H2S gas concentration and absorption spectrum was built. Result shows that while the concentration alters from 0 to 9.32%, a linear response of AOS signal to H2S concentration was observed with the response sensitivity of 0.332 dBm/% and linearity R2=0.9966. Such H2S sensor is suitable for monitoring the H2S hazard as a one time disposable logging-while-drilling sensor.

  4. Biogenesis of reactive sulfur species for signaling by hydrogen sulfide oxidation pathways

    PubMed Central

    Mishanina, Tatiana V; Libiad, Marouane; Banerjee, Ruma

    2016-01-01

    The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity. PMID:26083070

  5. Biogenesis of reactive sulfur species for signaling by hydrogen sulfide oxidation pathways.

    PubMed

    Mishanina, Tatiana V; Libiad, Marouane; Banerjee, Ruma

    2015-07-01

    The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity.

  6. Toward new instruments for measurement of low concentration hydrogen sulfide in small-quantity aqueous solutions

    NASA Astrophysics Data System (ADS)

    Wu, Xiao Chu; Qing Wu, Dong; Sammynaiken, R.; Yang, Wei; Wang, Rui; Zhang, W. J.

    2008-11-01

    Endogenously generated hydrogen sulfide (H2S) has been found to play some important physiological roles in the nervous and cardiovascular systems, such as a neuromodulator and a vasorelaxant. These roles are in contrast to our common perception that H2S is toxic. However, whether H2S plays a positive or negative role is dependent on the H2S concentration levels in mammals. This further puts a high demand on the accurate measurement of H2S in mammals with a further desire to be real time, continuous and in vivo. Existing methods for H2S measurement require a large number of tissue samples with complex procedures, and these methods are extremely invasive. The development of new in vivo and real-time methods for measuring H2S is, however, a great challenge. In the present study, we proposed and examined five potential H2S measurement methods: (1) atomic force microscopy with coating materials, (2) Raman spectroscopy on the H2S solutions, (3) gas chromatography/mass spectroscopy (with the static headspace technique) on the H2S solutions, (4) mass spectroscopy on unfunctionalized carbon nanotubes treated with the H2S solutions and (5) Raman spectroscopy on unfunctionalized carbon nanotubes treated with the H2S solutions. Our study concluded that method (5) is the most promising one for detecting low concentration H2S in small-quantity aqueous solutions in terms of measurement resolution and non-invasiveness, but the method is not very robust.

  7. Hydrogen sulfide in signaling pathways.

    PubMed

    Olas, Beata

    2015-01-15

    For a long time hydrogen sulfide (H₂S) was considered a toxic compound, but recently H₂S (at low concentrations) has been found to play an important function in physiological processes. Hydrogen sulfide, like other well-known compounds - nitric oxide (NO) and carbon monoxide (CO) is a gaseous intracellular signal transducer. It regulates the cell cycle, apoptosis and the oxidative stress. Moreover, its functions include neuromodulation, regulation of cardiovascular system and inflammation. In this review, I focus on the metabolism of hydrogen sulfide (including enzymatic pathways of H₂S synthesis from l- and d-cysteine) and its signaling pathways in the cardiovascular system and the nervous system. I also describe how hydrogen sulfide may be used as therapeutic agent, i.e. in the cardiovascular diseases.

  8. Thiosulfate Mediates Cytoprotective Effects of Hydrogen Sulfide Against Neuronal Ischemia.

    PubMed

    Marutani, Eizo; Yamada, Marina; Ida, Tomoaki; Tokuda, Kentaro; Ikeda, Kohei; Kai, Shinichi; Shirozu, Kazuhiro; Hayashida, Kei; Kosugi, Shizuko; Hanaoka, Kenjiro; Kaneki, Masao; Akaike, Takaaki; Ichinose, Fumito

    2015-11-06

    Hydrogen sulfide (H2S) exhibits protective effects in various disease models including cerebral ischemia-reperfusion (I/R) injury. Nonetheless, mechanisms and identity of molecules responsible for neuroprotective effects of H2S remain incompletely defined. In the current study, we observed that thiosulfate, an oxidation product of H2S, mediates protective effects of an H2S donor compound sodium sulfide (Na2S) against neuronal I/R injury. We observed that thiosulfate in cell culture medium is not only required but also sufficient to mediate cytoprotective effects of Na2S against oxygen glucose deprivation and reoxygenation of human neuroblastoma cell line (SH-SY5Y) and murine primary cortical neurons. Systemic administration of sodium thiosulfate (STS) improved survival and neurological function of mice subjected to global cerebral I/R injury. Beneficial effects of STS, as well as Na2S, were associated with marked increase of thiosulfate, but not H2S, in plasma and brain tissues. These results suggest that thiosulfate is a circulating "carrier" molecule of beneficial effects of H2S. Protective effects of thiosulfate were associated with inhibition of caspase-3 activity by persulfidation at Cys163 in caspase-3. We discovered that an SLC13 family protein, sodium sulfate cotransporter 2 (SLC13A4, NaS-2), facilitates transport of thiosulfate, but not sulfide, across the cell membrane, regulating intracellular concentrations and thus mediating cytoprotective effects of Na2S and STS. The protective effects of H2S are mediated by thiosulfate that is transported across cell membrane by NaS-2 and exerts antiapoptotic effects via persulfidation of caspase-3. Given the established safety track record, thiosulfate may be therapeutic against ischemic brain injury. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  9. Hydrogen Sulfide: A Signal Molecule in Plant Cross-Adaptation

    PubMed Central

    Li, Zhong-Guang; Min, Xiong; Zhou, Zhi-Hao

    2016-01-01

    For a long time, hydrogen sulfide (H2S) has been considered as merely a toxic by product of cell metabolism, but nowadays is emerging as a novel gaseous signal molecule, which participates in seed germination, plant growth and development, as well as the acquisition of stress tolerance including cross-adaptation in plants. Cross-adaptation, widely existing in nature, is the phenomenon in which plants expose to a moderate stress can induce the resistance to other stresses. The mechanism of cross-adaptation is involved in a complex signal network consisting of many second messengers such as Ca2+, abscisic acid, hydrogen peroxide and nitric oxide, as well as their crosstalk. The cross-adaptation signaling is commonly triggered by moderate environmental stress or exogenous application of signal molecules or their donors, which in turn induces cross-adaptation by enhancing antioxidant system activity, accumulating osmolytes, synthesizing heat shock proteins, as well as maintaining ion and nutrient balance. In this review, based on the current knowledge on H2S and cross-adaptation in plant biology, H2S homeostasis in plant cells under normal growth conditions; H2S signaling triggered by abiotic stress; and H2S-induced cross-adaptation to heavy metal, salt, drought, cold, heat, and flooding stress were summarized, and concluded that H2S might be a candidate signal molecule in plant cross-adaptation. In addition, future research direction also has been proposed. PMID:27833636

  10. Micro-aeration for hydrogen sulfide removal from biogas

    NASA Astrophysics Data System (ADS)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration

  11. H2S Analysis in Biological Samples Using Gas Chromatography with Sulfur Chemiluminescence Detection

    PubMed Central

    Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) is a metabolite and signaling molecule in biological tissues that regulates many physiological processes. Reliable and sensitive methods for H2S analysis are necessary for a better understanding of H2S biology and for the pharmacological modulation of H2S levels in vivo. In this chapter, we describe the use of gas chromatography coupled to sulfur chemiluminescence detection to measure the rates of H2S production and degradation by tissue homogenates at physiologically relevant concentrations of substrates. This method allows separation of H2S from other sulfur compounds and provides sensitivity of detection to ~15 pg (or 0.5 pmol) of H2S per injected sample. PMID:25725519

  12. Spurious hydrogen sulfide production by Providencia and Escherichia coli species.

    PubMed Central

    Treleaven, B E; Diallo, A A; Renshaw, E C

    1980-01-01

    Hydrogen sulfide production was noted in two Escherichia coli strands and one Provaidenica alcalifaciens (Proteus inconstans A) strain isolated from clinical stool specimens durin the summer of 1979. An investigation into this phenomenon revealed the predence of Eubacterium lentum, an anaerobe, growing in synergism with the Enterobacteriaceae and producing H2s. The implications of this association are discssed with reference to clinical microbiology laboratory practice. PMID:7000823

  13. Ambient geothermal hydrogen sulfide exposure and peripheral neuropathy.

    PubMed

    Pope, Karl; So, Yuen T; Crane, Julian; Bates, Michael N

    2017-05-01

    The mechanism of toxicity of hydrogen sulfide (H2S) gas is thought mainly to operate through effects on the nervous system. The gas has high acute toxicity, but whether chronic exposure causes effects, including peripheral neuropathy, is yet unclear. The city of Rotorua, New Zealand, sits on an active geothermal field and the population has some of the highest measured ambient H2S exposures. A previous study in Rotorua provided evidence that H2S is associated with peripheral neuropathy. Using clinical methods, the present study sought to investigate and possibly confirm this association in the Rotorua population. The study population comprised 1635 adult residents of Rotorua, aged 18-65. Collected data relevant to the peripheral neuropathy investigation included symptoms, ankle stretch reflex, vibration sensitivity, as measured by the timed-tuning fork test and a Bio-Thesiometer (Bio-Medical Instrument Co., Ohio), and light touch sensitivity measured by monofilaments. An exposure metric, estimating time-weighted H2S exposure across the last 30 years was used. Principal components analysis was used to combine data across the various indicators of possible peripheral neuropathy. The main data analysis used linear regression to examine associations between the peripheral nerve function indicators and H2S exposure. None of the peripheral nerve function indicators were associated with H2S exposure, providing no evidence that H2S exposure at levels found in Rotorua is a cause of peripheral neuropathy. The earlier association between H2S exposure and peripheral neuropathy diagnoses may be attributable to the ecological study design used. The possibility that H2S exposure misclassification could account for the lack of association found cannot be entirely excluded. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Regulation of soluble guanylyl cyclase redox state by hydrogen sulfide.

    PubMed

    Zhou, Zongmin; Martin, Emil; Sharina, Iraida; Esposito, Iolanda; Szabo, Csaba; Bucci, Mariarosaria; Cirino, Giuseppe; Papapetropoulos, Andreas

    2016-09-01

    Soluble guanylate cyclase (sGC) is a receptor for nitric oxide (NO). Binding of NO to ferrous (Fe(2+)) heme increases its catalytic activity, leading to the production of cGMP from GTP. Hydrogen sulfide (H2S) is a signaling molecule that exerts both direct and indirect anti-oxidant effects. In the present, study we aimed to determine whether H2S could regulate sGC redox state and affect its responsiveness to NO-releasing agents and sGC activators. Using cultured rat aortic smooth muscle cells, we observed that treatment with H2S augmented the response to the NO donor DEA/NO, while attenuating the response to the heme-independent activator BAY58-2667 that targets oxidized sGC. Similarly, overexpression of H2S-synthesizing enzyme cystathionine-γ lyase reduced the ability of BAY58-2667 to promote cGMP accumulation. In experiments with phenylephrine-constricted mouse aortic rings, treatment with rotenone (a compound that increases ROS production), caused a rightward shift of the DEA/NO concentration-response curve, an effect partially restored by H2S. When rings were pre-treated with H2S, the concentration-response curve to BAY 58-2667 shifted to the right. Using purified recombinant human sGC, we observed that treatment with H2S converted ferric to ferrous sGC enhancing NO-donor-stimulated sGC activity and reducing BAY 58-2667-triggered cGMP formation. The present study identified an additional mechanism of cross-talk between the NO and H2S pathways at the level of redox regulation of sGC. Our results provide evidence that H2S reduces sGC heme Fe, thus, facilitating NO-mediated cellular signaling events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Hydrogen sulfide prolongs postharvest shelf life of strawberry and plays an antioxidative role in fruits.

    PubMed

    Hu, Lan-Ying; Hu, Shu-Li; Wu, Jun; Li, Yan-Hong; Zheng, Ji-Lian; Wei, Zhao-Jun; Liu, Jian; Wang, Hui-Li; Liu, Yong-Sheng; Zhang, Hua

    2012-09-05

    Accumulating evidence shows that hydrogen sulfide (H(2)S) plays various physiological roles in plants, such as seed germination, root organogenesis, abiotic stress tolerance, and senescence of cut flowers. However, whether H(2)S participates in the regulation of ripening and senescence in postharvest fruits remains unknown. In the present study, the effect of H(2)S on postharvest shelf life and antioxidant metabolism in strawberry fruits was investigated. Fumigation with H(2)S gas released from the H(2)S donor NaHS prolonged postharvest shelf life of strawberry fruits in a dose-dependent manner. Strawberry fruits fumigated with various concentrations of H(2)S sustained significantly lower rot index, higher fruit firmness, and kept lower respiration intensity and polygalacturonase activities than controls. Further investigation showed that H(2)S treatment maintained higher activities of catalase, guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase and lower activities of lipoxygenase relative to untreated controls. H(2)S also reduced malondialdehyde, hydrogen peroxide, and superoxide anion to levels below control fruits during storage. Moreover, H(2)S treatment maintained higher contents of reducing sugars, soluble proteins, free amino acid, and endogenous H(2)S in fruits. We interpret these data as indicating that H(2)S plays an antioxidative role in prolonging postharvest shelf life of strawberry fruits.

  16. Hydrogen sulfide generation in simulated construction and demolition debris landfills: impact of waste composition.

    PubMed

    Yang, Kenton; Xu, Qiyong; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel; Booth, Matthew

    2006-08-01

    Hydrogen sulfide (H2S) generation in construction and demolition (C&D) debris landfills has been associated with the biodegradation of gypsum drywall. Laboratory research was conducted to observe H2S generation when drywall was codisposed with different C&D debris constituents. Two experiments were conducted using simulated landfill columns. Experiment 1 consisted of various combinations of drywall, wood, and concrete to determine the impact of different waste constituents and combinations on H2S generation. Experiment 2 was designed to examine the effect of concrete on H2S generation and migration. The results indicate that decaying drywall, even alone, leached enough sulfate ions and organic matter for sulfate-reducing bacteria (SRB) to generate large H2S concentrations as high as 63,000 ppmv. The codisposed wastes show some effect on H2S generation. At the end of experiment 1, the wood/drywall and drywall alone columns possessed H2S concentrations > 40,000 ppmv. Conversely, H2S concentrations were < 1 ppmv in those columns containing concrete. Concrete plays a role in decreasing H2S by increasing pH out of the range for SRB growth and by reacting with H2S. This study also showed that wood lowered H2S concentrations initially by decreasing leachate pH values. Based on the results, two possible control mechanisms to mitigate H2S generation in C&D debris landfills are suggested.

  17. Role of Cystathionine γ-Lyase/Hydrogen Sulfide Pathway in Cardiovascular Disease: A Novel Therapeutic Strategy?

    PubMed Central

    Pan, Li Long; Liu, Xin Hua; Gong, Qi Hai; Yang, He Bei

    2012-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has traditionally been considered a toxic environmental pollutant. In the late 1990s, the presumed solely harmful role of H2S has been challenged because H2S may also be involved in the maintenance and preservation of cardiovascular homeostasis. Recent Advances: The production of endogenous H2S has been attributed to three key enzymes, cystathionine γ-lyase (CSE), cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase. The recognition of H2S as the third gaseous signaling molecule has stimulated research on a multitude of pathophysiologic events in the cardiovascular system. In particular, important roles in cardiovascular disorder processes are ascribed to the CSE/H2S pathway, such as atherosclerosis, myocardial infarction, hypertension, and shock. Critical Issues: Many biological activities and molecular mechanisms of H2S in the cardiovascular system have been demonstrated in studies using different tools, such as the genetic overexpression of CSE, the direct administration of H2S donors, or the use of H2S-releasing pro-drugs. Unfortunately, the role of the CSE/H2S pathway in cardiovascular disease remains controversial in numerous areas, and many questions regarding the gaseous molecule still remain unanswered. Future Directions: Advances in basic research indicate that the CSE/H2S pathway may provide potential therapeutic targets for treating cardiovascular disorders. But the molecular targets of H2S still need to be identified. Antioxid. Redox Signal. 17, 106–118. PMID:22017202

  18. Hydrogen sulfide in a circumstellar envelope

    NASA Technical Reports Server (NTRS)

    Ukita, N.; Morris, M.

    1983-01-01

    A search for hydrogen sulfide in the cool circumstellar envelopes of 25 stars was made using the 1(10)-1(01) rotational line at 1.8 mm. It was detected in the bipolar nebula/OH maser OH231.8+4.2, an object having a high rate of mass loss. An approximate analysis indicates that 1/60 of the sulfur in this outflowing envelope is in the form of H2S, a fraction which may be similar to that in the atmosphere of the central star. In addition, the shape of the observed line profile is discussed in terms of a possible variation of the outflow velocity with latitude above the system's equatorial plane.

  19. Roles of H2S in adaptation of alpine plants Lamiophlomis rotata to altitude gradients

    PubMed Central

    Ma, Lan; Yang, Yongping; Hu, Xiangyang

    2015-01-01

    Hydrogen sulfide (H2S) is an important gaseous transmitter in organisims. It widespreads in the organs and tissues of animals and participates in the biological process of cardiovascular relaxation, cell apoptosis and protection, inflammation and neuromodulation. H2S also can be synthesized in plants system and is involved in stress responses and the biological process of growth and development. This review describes the synthesis and biological function of H2S in plants. Based on our research for the adaptation of Lamiophlomis rotata to different altitude gradients, we firstly proposed H2S plays an important role in the adaptation of Lamiophlomis rotata to alpine environment. PMID:26786014

  20. Hydrogen Sulfide as a "Double-Faced" Compound: One with Pro- and Antioxidant Effect.

    PubMed

    Olas, B

    2017-01-01

    Hydrogen sulfide (H2S), like other gasotransmitters such as nitric oxide (NO(•)) and carbon monoxide (CO), acts as a signaling molecule in various biological systems. It may also regulate the oxidative stress observed in several diseases sometimes associated with changes of H2S concentration. This chapter describes the "double face" of hydrogen sulfide as both an antioxidant and a prooxidant in biological systems. One proposed mechanism by which H2S exerts its antioxidative effects is its ability to modulate the concentration of glutathione, which is a very important physiological antioxidant. This chapter discusses the interactions of H2S with various reactive oxygen species and reactive nitrogen species, including the superoxide radical anion [Formula: see text] , hydrogen peroxide (H2O2), and peroxynitrite anion (ONOO(-)), which is produced in a rapid reaction between [Formula: see text] and NO(•).

  1. Neuroprotective effects of hydrogen sulfide and the underlying signaling pathways.

    PubMed

    Chen, Wen-Lin; Niu, Ying-Ying; Jiang, Wei-Zheng; Tang, Hui-Lan; Zhang, Chong; Xia, Qi-Ming; Tang, Xiao-Qing

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenously produced gas that represents a novel third gaseous signaling molecule, neurotransmitter and cytoprotectant. Cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), 3-mercaptopyruvate sulfur transferase with cysteine aminotransferase (3-MST/CAT) and 3-mercaptopyruvate sulfur transferase with d-amino acid oxidase (3-MST/DAO) pathways are involved in the generation of endogenous H2S despite the ubiquitous or restricted distribution of those enzymes. CBS, 3-MST/CAT and 3-MST/DAO can be found in the brain, while CSE is widely located in other organs. There also exist up-taking or recycling and scavenging mechanisms in H2S metabolism to maintain its persistence for physiological function. In recent years, investigating the role that H2S plays in the central nervous system and cardiovascular system has always been a hotspot. To date, effects of H2S are at least partially verified in multiple animal models or neuron cell lines of Alzheimer's disease, Parkinson's disease, cerebral ischemia, major depression disorders and febrile seizure, although subsequent studies are still badly needed. This article presents an overview of current knowledge of H2S focusing on its neuroprotective effects and corresponding signaling pathways, together with connections to potential therapeutic strategies in the clinic.

  2. Hydrogen sulfide and cell signaling: team player or referee?

    PubMed

    Hancock, J T; Whiteman, M

    2014-05-01

    Hydrogen sulfide (H2S) has been postulated to be the third gasotransmitter, and along with other reactive compounds such as reactive oxygen species (ROS) and nitric oxide (NO) it is thought to be a key signalling molecule. Enzymes which generate H2S, and remove it, have been characterised in both plants and animals and although it is inherently toxic to cells - inhibiting cytochrome oxidase for example - H2S is now being thought of as part of signal transduction pathways. But is it working as a signal in the sense usually seen for small signalling molecules, that is, produced when needed, perceived and leading to dedicated responses in cells? A look through the literature shows that H2S is involved in many stress responses, and in animals is implicated in the onset of many diseases, in both cases where ROS and NO are often involved. It is suggested here that H2S is not acting as a true signal, but through its interaction with NO and ROS metabolism is modulating such activity, keeping it in check unless strictly needed, and that H2S is acting as a referee to ensure NO and ROS metabolism is working properly.

  3. Hydrogen sulfide and oxygen sensing in the cardiovascular system.

    PubMed

    Olson, Kenneth R; Whitfield, Nathan L

    2010-05-15

    Vertebrate cardiorespiratory homeostasis is inextricably dependent upon specialized cells that provide feedback on oxygen status in the tissues, blood, and on occasion, environment. These "oxygen sensing" cells include chemoreceptors and oxygen-sensitive chromaffin cells that initiate cardiorespiratory reflexes, vascular smooth muscle cells that adjust perfusion to metabolism or ventilation, and other cells that condition themselves in response to episodic hypoxia. Identification of how these cells sense oxygen and transduce this into the appropriate physiological response has enormous clinical applicability, but despite intense research there is no consensus regarding the initial hypoxia-effector coupling mechanism. This review examines an alternative mechanism of oxygen sensing using oxidation of endogenously produced hydrogen sulfide (H(2)S) as the O(2)-sensitive couple. Support for this hypothesis includes the similarity of effects of hypoxia and H(2)S on a variety of tissues, augmentation of hypoxic responses by precursors of H(2)S production and their inhibition by inhibitors of H(2)S synthesis, and the rapid consumption of H(2)S by O(2) in the range of intracellular/mitochondrial Po(2). These studies also indicate that, under normoxic conditions, it is doubtful that free H(2)S has longer than a transient existence in tissue or extracellular fluid.

  4. Hydrogen sulfide exposure increases desiccation tolerance in Drosophila melanogaster.

    PubMed

    Zhong, Jian-Feng; Wang, Shu-Ping; Shi, Xiao-Qin; Mu, Li-li; Li, Guo-Qing

    2010-12-01

    Hydrogen sulfide (H(2)S) has been shown to effect physiological alterations in several animals, frequently leading to an improvement in survival in otherwise lethal conditions. In the present paper, a volatility bioassay system was developed to evaluate the survivorship of Drosophila melanogaster adults exposed to H(2)S gas that emanated from a K(2)S donor. Using this bioassay system, we found that H(2)S exposure significantly increased the survival of flies under arid and food-free conditions, but not under humid and food-free conditions. This suggests that H(2)S plays a role in desiccation tolerance but not in nutritional stress alleviation. To further confirm the suggestion, the mRNA levels of two desiccation tolerance-related genes Frost and Desat2, and a starvation-related gene Smp-30, from the control and treated flies were measured by quantitative real-time PCR. These genes were up-regulated within 2h when the flies transferred to the arid and food-free bioassay system. Addition of H(2)S further increased Frost and Desat2 mRNA levels, in contrast to Smp-30. Thus, our molecular results were consistent with our bioassay findings. Because of the molecular and genetic tools available for Drosophila, the fly will be a useful system for determining how H(2)S regulates various physiological alterations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. H2S during circulatory shock: Some unresolved questions

    PubMed Central

    McCook, Oscar; Radermacher, Peter; Volani, Chiara; Asfar, Pierre; Ignatius, Anita; Kemmler, Julia; Möller, Peter; Szabó, Csaba; Whiteman, Matthew; Wood, Mark E.; Wang, Rui; Georgieff, Michael; Wachter, Ulrich

    2014-01-01

    Numerous papers have been published on the role of H2S during circulatory shock. Consequently, knowledge about vascular sulfide concentrations may assume major importance, in particular in the context of “acute on chronic disease”, i.e., during circulatory shock in animals with pre-existing chronic disease. This review addresses the questions i) of the “real” sulfide levels during circulatory shock, and, ii) to which extent injury and pre-existing co-morbidity may affect the expression of H2S producing enzymes under these conditions. In the literature there is a huge range on sulfide blood levels during circulatory shock, in part as a result of the different analytical methods used, but also due to the variable of the models and species studied. Clearly, some of the very high levels reported should be questioned in the context of the well-known H2S toxicity. As long as “real” sulfide levels during circulatory shock are unknown and/or undetectable “on line” due to the lack of appropriate techniques, it appears to be premature to correlate the measured blood levels of hydrogen sulfide with the severity of shock or the H2S therapy-related biological outcomes. The available data on the tissue expression of the H2S-releasing enzymes during circulatory shock suggest that a “constitutive” CSE expression may play a crucial role of for the maintenance of organ function, at least in the kidney. The data also indicate that increased CBS and CSE expression, in particular in the lung and the liver, represents an adaptive response to stress states. PMID:24650697

  6. An intercomparison of aircraft instrumentation for tropospheric measurements of carbonyl sulfide, hydrogen sulfide, and carbon disulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Davis, Douglas D.; Thornton, Donald C.; Johnson, James E.; Bandy, Alan R.; Saltzman, Eric S.; Andreae, Meinrat O.; Barrick, John D.

    1993-01-01

    This paper reports results of NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements for carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were intercompared. Instrumentation included a gas chromatograph using flame photometric detection (COS, H2S, and CS2), a gas chromatograph using mass spectrometric detection (COS) and CS2), a gas chromatograph using fluorination and subsequent SF6 detection via electron capture (COS and CS2), and the Natusch technique (H2S). The measurements were made over the Atlantic Ocean east of North and South America during flights from NASA's Wallops Flight Center, Virginia, and Natal, Brazil, in August/September 1989. Most of the intercomparisons for H2S and CS2 were at mixing ratios less than 25 pptv and less than 10 pptv, respectively, with a maximum mixing ratio of about 100 pptv and 50 pptv, respectively. Carbonyl sulfide intercomparisons were at mixing ratios between 400 and 600 pptv. Measurements were intercompared from data bases constructed from time periods of simultaneous or overlapping measurements. Agreement among the COS techniques averaged about 5%, and individual measurements were generally within 10%. For H2S and at mixing ratio greater than 25 pptv, the instruments agreed on average to about 15%. At mixing ratios less than 25 pptv the agreement was about 5 pptv. For CS2 (mixing ratios less than 50 pptv), two techniques agreed on average to about 4 pptv, and the third exhibited a bias (relative to the other two) that varied in the range of 3-7 pptv. CS2 mixing ratios over the ocean east of Natal as measured by the gas chromatograph-mass spectrometer technique were only a few pptv and were below the detection limits of the other two techniques. The CITE 3 data are used to estimate the current uncertainty associated with aircraft measurements of COS, H2S, and CS2 in the remote troposphere.

  7. Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review

    PubMed Central

    Greabu, Maria; Totan, Alexandra; Miricescu, Daniela; Radulescu, Radu; Virlan, Justina; Calenic, Bogdan

    2016-01-01

    In the past years, biomedical research has recognized hydrogen sulfide (H2S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H2S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H2S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases. PMID:26805896

  8. Protein-based nanobiosensor for direct detection of hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Omidi, Meisam; Amoabediny, Ghasem; Yazdian, Fatemeh; Habibi-Rezaei, M.

    2015-01-01

    The chemically modified cytochrome c from equine heart, EC (232-700-9), was immobilized onto gold nanoparticles in order to develop a specific biosensing system for monitoring hydrogen sulfide down to the micromolar level, by means of a localized surface plasmon resonance spectroscopy. The sensing mechanism is based on the cytochrome-c conformational changes in the presence of H2S which alter the dielectric properties of the gold nanoparticles and the surface plasmon resonance peak undergoes a redshift. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 μ \\text{M} (1.3 \\text{ppb}) by the fabricated biosensor. This simple, quantitative and sensitive sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

  9. Reduced adipose tissue H2S in obesity.

    PubMed

    Katsouda, Antonia; Szabo, Csaba; Papapetropoulos, Andreas

    2017-10-02

    Hydrogen sulfide (H2S) is an endogenously produced signaling molecule synthesized by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). Given that H2S exerts significant effects on bioenergetics and metabolism, the goal of the current study was to determine the expression of H2S-producing enzymes in adipose tissues in models of obesity and metabolic disruption. Mice fed a western diet expressed lower mRNA levels of all three enzymes in epididymal fat (EWAT), while only CSE and 3-MST were reduced in brown adipose tissue (BAT). At the protein level 3-MST was reduced in all fat depots studied. Using db/db mice, a genetic model of obesity, we found that CSE, CBS and 3-MST mRNA were reduced in white fat, while only CSE was reduced in BAT. CBS and CSE protein levels were suppressed in all three fat depots. In a model of age-related weight gain, no reduction in the mRNA of any of the enzymes was noted. Smaller amounts of 3-MST protein were found in EWAT, while both CSE and 3-MST were reduced in BAT. Tissue levels of H2S were lower in WAT in HFD mice; both WAT and BAT contained lower H2S amounts in db/db animals. Taken together, our data suggest that obesity is associated with a decreased expression of H2S-synthesizing enzymes and reduced H2S levels in adipose tissues of mice. We propose that the reduction in H2S may contribute to the metabolic response associated with obesity. Further work is needed to determine whether restoring H2S levels during obesity may have a beneficial effect on obesity-associated metabolic alterations. Copyright © 2017. Published by Elsevier Ltd.

  10. Emerging role of hydrogen sulfide-microRNA crosstalk in cardiovascular diseases

    PubMed Central

    Hackfort, Bryan T.

    2016-01-01

    Despite an obnoxious smell and toxicity at a high dose, hydrogen sulfide (H2S) is emerging as a cardioprotective gasotransmitter. H2S mitigates pathological cardiac remodeling by regulating several cellular processes including fibrosis, hypertrophy, apoptosis, and inflammation. These encouraging findings in rodents led to initiation of a clinical trial using a H2S donor in heart failure patients. However, the underlying molecular mechanisms by which H2S mitigates cardiac remodeling are not completely understood. Empirical evidence suggest that H2S may regulate signaling pathways either by directly influencing a gene in the cascade or interacting with nitric oxide (another cardioprotective gasotransmitter) or both. Recent studies revealed that H2S may ameliorate cardiac dysfunction by up- or downregulating specific microRNAs. MicroRNAs are noncoding, conserved, regulatory RNAs that modulate gene expression mostly by translational inhibition and are emerging as a therapeutic target for cardiovascular disease (CVD). Few microRNAs also regulate H2S biosynthesis. The inter-regulation of microRNAs and H2S opens a new avenue for exploring the H2S-microRNA crosstalk in CVD. This review embodies regulatory mechanisms that maintain the physiological level of H2S, exogenous H2S donors used for increasing the tissue levels of H2S, H2S-mediated regulation of CVD, H2S-microRNAs crosstalk in relation to the pathophysiology of heart disease, clinical trials on H2S, and future perspectives for H2S as a therapeutic agent for heart failure. PMID:26801305

  11. Synergistic effects of Ni 1- xCo x-YSZ and Ni 1- xCu x-YSZ alloyed cermet SOFC anodes for oxidation of hydrogen and methane fuels containing H 2S

    NASA Astrophysics Data System (ADS)

    Grgicak, Catherine M.; Pakulska, Malgosia M.; O'Brien, Julie S.; Giorgi, Javier B.

    Preparation and performance of bimetallic Ni (1- x)Co x-YSZ and Ni (1- x)Cu x-YSZ anodes were tested to overcome common deficiencies of carbon and sulfur poisoning in SOFCs. Ni 1- xCo xO-YSZ and Ni (1- x)Cu xO-YSZ precursors were synthesized via co-precipitation of their respective chlorides. Single cell solid oxide fuel cells of these bimetallic anodes were tested in H 2, CH 4, and H 2S/CH 4 fuel mixtures. Addition of Cu 2+ into the NiO lattice resulted in large metal particle sizes and decreased SOFC performance. Addition of Co 2+ into the NiO lattice to form Ni 0.92Co 0.08O-YSZ anode precursor produced a cermet with a large BET surface area and active metal surface area, thus increasing the rate of hydrogen oxidation for this sample. The performance of both bimetallics was found to quickly degrade in dry CH 4 due to carbon deposition and lifting of the anode from the electrolyte. However, Ni 0.69Co 0.31-YSZ showed superior activity in a 10% (v/v) H 2S/CH 4 fuel mixture, surpassing performance with H 2 fuel, thereby demonstrating the exciting prospect of using sulfidated Ni (1- x)Co x-YSZ as SOFC anodes in sulfur containing methane streams. The active anode becomes a sulfidated alloy (Ni-Co-S) under operating conditions. This anode showed enhanced performance, which surpassed those of sulfidated Ni and Co anodes, thereby suggesting a synergistic behaviour in the Ni-Co-S anode.

  12. H2S-Releasing Polymer Micelles for Studying Selective Cell Toxicity.

    PubMed

    Foster, Jeffrey C; Radzinski, Scott C; Zou, Xianlin; Finkielstein, Carla V; Matson, John B

    2017-04-03

    We report the preparation of S-aroylthiooxime (SATO) functionalized amphiphilic block copolymer micelles that release hydrogen sulfide (H2S), a gaseous signaling molecule of relevance to various physiological and pathological conditions. The micelles release H2S in response to cysteine with a half-life of 3.3 h, which is substantially slower than a related small molecule SATO. Exogenous administration of H2S impacts growth and proliferation of cancer cells; however, the limited control over H2S generation from inorganic sulfide sources results in conflicting reports. Therefore, we compare the cellular cytotoxicity of SATO-functionalized micelles, which release H2S in a sustained manner, to Na2S, which releases H2S in a single dose. Our results show that H2S-releasing micelles significantly reduce the survival of HCT116 colon cancer cells relative to Na2S, GYY4137, and a small molecule SATO, indicating that release kinetics may play an important role in determining toxicity of H2S toward cancer cells. Furthermore, H2S-releasing micelles are well tolerated by immortalized fibroblasts (NIH/3T3 cells), suggesting a selective toxicity of H2S toward cancer cells.

  13. Novel cooperative interactions and structural ordering in H2S-H2

    SciTech Connect

    Kent, Paul R

    2011-01-01

    Hydrogen sulfide (H2S) and hydrogen (H2) crystallize into a 'guest-host' structure at 3.5 GPa and, at the initial formation pressure, the rotationally disordered component molecules exhibit weak van der Waals type interactions. With increasing pressure, hydrogen bonding develops and strengthens between neighboring H2S molecules, reflected in a pronounced drop in S-H vibrational stretching frequency and also observed in first-principles calculations. At 17 GPa, an ordering process occurs where H2S molecules orient themselves to maximize hydrogen bonding and H2 molecules simultaneously occupy a chemically distinct lattice site. Intermolecular forces in the H2S+H2 system may be tuned with pressure from the weak hydrogen-bonding limit to the ordered hydrogen-bonding regime, resulting in a novel clathrate structure stabilized by cooperative interactions.

  14. Reactive Precipitation of Anhydrous Alkali Sulfide Nanocrystals with Concomitant Abatement of Hydrogen Sulfide and Cogeneration of Hydrogen.

    PubMed

    Li, Xuemin; Zhao, Yangzhi; Brennan, Alice; McCeig, Miranda; Wolden, Colin A; Yang, Yongan

    2017-07-21

    Anhydrous alkali sulfide (M2 S, M=Li or Na) nanocrystals (NCs) are important materials central to the development of next generation cathodes and solid-state electrolytes for advanced batteries, but not commercially available at present. This work reports an innovative method to directly synthesize M2 S NCs through alcohol-mediated reactions between alkali metals and hydrogen sulfide (H2 S). In the first step, the alkali metal is complexed with alcohol in solution, forming metal alkoxide (ROM) and releasing hydrogen (H2 ). Next, H2 S is bubbled through the ROM solution, where both chemicals are completely consumed to produce phase-pure M2 S NC precipitates and regenerate alcohol that can be recycled. The M2 S NCs morphology may be tuned through the choice of the alcohol and solvent. Both synthetic steps are thermodynamically favorable (ΔGm(o) <-100 kJ mol(-1) ), proceeding rapidly to completion at ambient temperature with almost 100 % atom efficiency. The net result, H2 S+2 m→M2 S+H2 , makes good use of a hazardous chemical (H2 S) and delivers two value-added products that naturally phase separate for easy recovery. This scalable approach provides an energy-efficient and environmentally benign solution to the production of nanostructured materials required in emerging battery technologies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Role of hydrogen sulfide in secondary neuronal injury.

    PubMed

    Wang, Jun-Feng; Li, Yu; Song, Jin-Ning; Pang, Hong-Gang

    2014-01-01

    In acute neuronal insult events, such as stroke, traumatic brain injury, and spinal cord injury, pathological processes of secondary neuronal injury play a key role in the severity of insult and clinical prognosis. Along with nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H2S) is regarded as the third gasotransmitter and endogenous neuromodulator and plays multiple roles in the central nervous system under physiological and pathological states, especially in secondary neuronal injury. The endogenous level of H2S in the brain is significantly higher than that in peripheral tissues, and is mainly formed by cystathionine β-synthase (CBS) in astrocytes and released in response to neuronal excitation. The mechanism of secondary neuronal injury exacerbating the damage caused by the initial insult includes microcirculation failure, glutamate-mediated excitotoxicity, oxidative stress, inflammatory responses, neuronal apoptosis and calcium overload. H2S dilates cerebral vessels by activating smooth muscle cell plasma membrane ATP-sensitive K channels (KATP channels). This modification occurs on specific cysteine residues of the KATP channel proteins which are S-sulfhydrated. H2S counteracts glutamate-mediated excitotoxicity by inducing astrocytes to intake more glutamate from the extracellular space and thus increasing glutathione in neurons. In addition, H2S protects neurons from secondary neuronal injury by functioning as an anti-oxidant, anti-inflammatory and anti-apoptotic mediator. However, there are still some reports suggest that H2S elevates neuronal Ca(2+) concentration and may contribute to the formation of calcium overload in secondary neuronal injury. H2S also elicits calcium waves in primary cultures of astrocytes and may mediate signals between neurons and glia. Consequently, further exploration of the molecular mechanisms of H2S in secondary neuronal injury will provide important insights into its potential therapeutic uses for the treatment

  16. MET2 affects production of hydrogen sulfide during wine fermentation.

    PubMed

    Huang, Chien; Roncoroni, Miguel; Gardner, Richard C

    2014-08-01

    The production of hydrogen sulfide (H2S) during yeast fermentation contributes negatively to wine aroma. We have mapped naturally occurring mutations in commercial wine strains that affect production of H2S. A dominant R310G mutant allele of MET2, which encodes homoserine O-acetyltransferase, is present in several wine yeast strains as well as in the main lab strain S288c. Reciprocal hemizygosity and allele swap experiments demonstrated that the MET2 R310G allele confers reduced H2S production. Mutations were also identified in genes encoding the two subunits of sulfite reductase, MET5 and MET10, which were associated with reduced H2S production. The most severe of these, an allele of MET10, showed five additional phenotypes: reduced growth rate on sulfate, elevated secretion of sulfite, and reduced production in wine of three volatile sulfur compounds: methionol, carbon disulfide and methylthioacetate. Alleles of MET5 and MET10, but not MET2, affected H2S production measured by colour assays on BiGGY indicator agar, but MET2 effects were seen when bismuth was added to agar plates made with Sauvignon blanc grape juice. Collectively, the data are consistent with the hypothesis that H2S production during wine fermentation results predominantly from enzyme activity in the sulfur assimilation pathway. Lower H2S production results from mutations that reduce the activity of sulfite reductase, the enzyme that produces H2S, or that increase the activity of L-homoserine-O-acetyltransferase, which produces substrate for the next step in the sulfur assimilation pathway.

  17. Hydrogen Sulfide as an Endogenous Modulator in Mitochondria and Mitochondria Dysfunction

    PubMed Central

    Guo, Wei; Kan, Jun-tao; Cheng, Ze-yu; Chen, Jie-fang; Shen, Ya-qi; Xu, Jie; Wu, Dan; Zhu, Yi-zhun

    2012-01-01

    Hydrogen sulfide (H2S) has historically been considered to be a toxic gas, an environmental and occupational hazard. However, with the discovery of its presence and enzymatic production through precursors of L-cysteine and homocysteine in mammalian tissues, H2S has recently received much interest as a physiological signaling molecule. H2S is a gaseous messenger molecule that has been implicated in various physiological and pathological processes in mammals, including vascular relaxation, angiogenesis, and the function of ion channels, ischemia/reperfusion (I/R), and heart injury. H2S is an endogenous neuromodulator and present studies show that physiological concentrations of H2S enhance NMDA receptor-mediated responses and aid in the induction of hippocampal long-term potentiation. Moreover, in the field of neuronal protection, physiological concentrations of H2S in mitochondria have many favorable effects on cytoprotection. PMID:23304257

  18. Hydrogen Sulfide, the Next Potent Preventive and Therapeutic Agent in Aging and Age-Associated Diseases

    PubMed Central

    Zhang, Yuan; Tang, Zhi-Han; Ren, Zhong; Qu, Shun-Lin; Liu, Mi-Hua; Liu, Lu-Shan

    2013-01-01

    Hydrogen sulfide (H2S) is the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide. It is physiologically generated by cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase. H2S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems. Substantial evidence shows that H2S is involved in aging by inhibiting free-radical reactions, activating SIRT1, and probably interacting with the age-related gene Klotho. Moreover, H2S has been shown to have therapeutic potential in age-associated diseases. This article provides an overview of the physiological functions and effects of H2S in aging and age-associated diseases, and proposes the potential health and therapeutic benefits of H2S. PMID:23297346

  19. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOEpatents

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  20. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.

    PubMed

    Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

    2015-07-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors. © 2014 Institute of Botany, Chinese Academy of Sciences.

  1. [Hydrogen sulfide as a biologically active mediator in the cardiovascular system].

    PubMed

    Bełtowski, Jerzy

    2004-07-19

    Recent studies suggest that apart from nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H2S) is another inorganic gaseous mediator in the cardiovascular system. H2S is synthesized from L-cysteine by either cystathionine beta-synthase (CBS) or cystathionin gamma--lyase (CSE), both using pyridoxal 5'-phosphate (vitamin B6) as a cofactor. CBS is the main H2S-producing enzyme in the brain and CSE is involved in H2S formation in the cardiovascular system. H2S induces hypotension in vivo and vasodilation vitro by opening KATP channels in vascular smooth muscle cells. Chronic administration of CSE inhibitor induces arterial hypertension in the rat. In addition, decreased H2S generation has been demonstrated in the vasculature of spontaneously hypertensive rat, in experimental hypertension induced by NO synthase blockade, and in hypoxia-induced pulmonary hypertension, and administration of exogenous H2S donor has significant therapeutic effects in these models. Deficiency of H2S may contribute to atherogenesis in some patients with hyperhomocysteinemia, in whom the metabolism of homocysteine to cysteine and H2S is compromised by vitamin B6 deficiency. Reduced H2S production in the brain was observed in patients with Alzheimer's disease. On the other hand, excess of H2S may lead to mental retardation in patients with Down's syndrome and may be involved in the pathogenesis of hypotension associated with septic shock.

  2. Removal of H 2S via an iron catalytic cycle and iron sulfide precipitation in the water column of dead end tributaries

    NASA Astrophysics Data System (ADS)

    Ma, Shufen; Noble, Abigail; Butcher, Derek; Trouwborst, Robert E.; Luther, George W., III

    2006-11-01

    The oxidation and precipitation of H 2S were investigated in Torquay Canal and Bald Eagle Creek, two tributaries of northern Rehoboth Bay, one of the Delaware Inland Bays. These man-made dead end canals develop seasonal anoxia and have been the site of past fish kills and harmful algal blooms. The canals have multiple holes over 5.5 m deep compared to an average low tide depth of 2 m. In situ determination for dissolved O 2, H 2S and other Fe and S redox species were conducted with a solid-state Au/Hg microelectrode in 2003 and 2004. Laboratory analyses of discrete samples were also performed to measure dissolved and particulate Fe, Mn, and S 8 to follow the seasonal dynamics of O, S, Fe and Mn redox species. Our results indicate that the water in the holes becomes stratified with O 2 decreasing with depth and H 2S increasing with depth. Dissolved Fe was as high as 30 μM whereas dissolved Mn was only 0.2 μM in the water column, indicating that Fe is the dominant metal involved in S redox cycling and precipitation. In surface oxic waters, the dominant form of Fe was particulate Fe(III) (oxy)hydroxides. When seasonal anoxia developed, Fe(III) (oxy)hydroxides were reduced by H 2S to Fe(II) at the oxic-anoxic interface. The Fe(II) reduced from particulate Fe can be re-oxidized to Fe(III) by O 2 above and at the interface to form a catalytic cycle to oxidize H 2S. Elemental S is the predominant oxidation product and was as high as 30 μM level (as S 0) at the interface. When the system was stable, the Fe catalytic cycle prevented H 2S from being released into surface waters during seasonal anoxia. However, when storms came, the water column was overturned and H 2S was released to the surface water. The reaction rates for the Fe catalytic cycle are not fast enough and the concentration of Fe was not high enough to regulate the high concentration of H 2S in surface waters during storm and mixing events.

  3. Kinetics and the mass transfer mechanism of hydrogen sulfide removal by biochar derived from rice hull.

    PubMed

    Shang, Guofeng; Liu, Liang; Chen, Ping; Shen, Guoqing; Li, Qiwu

    2016-05-01

    The biochar derived from rice hull was evaluated for its abilities to remove hydrogen sulfide (H2S) from gas phase. The surface area and pH of the biochar were compared. The biochar derived from rice hull was evaluated for its abilities to remove hydrogen sulfide (H2S) from gas phase. The surface area and pH of the biochar were compared. The different pyrolysis temperature has great influence on the adsorption of H2S. At the different pyrolysis temperature, the H2S removal efficiency of rice hull-derived biochar was different. The adsorption capacities of biochar were 2.09 mg·g(-1), 2.65 mg·g(-1), 16.30 mg·g(-1), 20.80 mg·g(-1), and 382.70 mg·g(-1), which their pyrolysis temperatures were 100 °C, 200 °C, 300 °C, 400 °C and 500 °C respectively. Based on the Yoon-Nelson model, it analyzed the mass transfer mechanism of hydrogen sulfide adsorption by biochar. The paper focuses on the biochar derived from rice hull-removed hydrogen sulfide (H2S) from gas phase. The surface area and pH of the biochar were compared. The different pyrolysis temperatures have great influence on the adsorption of H2S. At the different pyrolysis temperatures, the H2S removal efficiency of rice hull-derived biohar was different. The adsorption capacities of biochar were 2.09, 2.65, 16.30, 20.80, and 382.70 mg·g(-1), and their pyrolysis temperatures were 100, 200, 300, 400, and 500 °C, respectively. Based on the Yoon-Nelson model, the mass transfer mechanism of hydrogen sulfide adsorption by biochar was analyzed.

  4. Esterase-Sensitive Prodrugs with Tunable Release Rates and Direct Generation of Hydrogen Sulfide.

    PubMed

    Zheng, Yueqin; Yu, Bingchen; Ji, Kaili; Pan, Zhixiang; Chittavong, Vayou; Wang, Binghe

    2016-03-24

    Prodrugs that release hydrogen sulfide upon esterase-mediated cleavage of an ester group followed by lactonization are described herein. By modifying the ester group and thus its susceptibility to esterase, and structural features critical to the lactonization rate, H2 S release rates can be tuned. Such prodrugs directly release hydrogen sulfide without the involvement of perthiol species, which are commonly encountered with existing H2 S donors. Additionally, such prodrugs can easily be conjugated to another non-steroidal anti-inflammatory agent, leading to easy synthesis of hybrid prodrugs. As a biological validation of the H2 S prodrugs, the anti-inflammatory effects of one such prodrug were examined by studying its ability to inhibit LPS-induced TNF-α production in RAW 264.7 cells. This type of H2 S prodrugs shows great potential as both research tools and therapeutic agents.

  5. Hydrogen sulfide in plants: from dissipation of excess sulfur to signaling molecule.

    PubMed

    Calderwood, Alexander; Kopriva, Stanislav

    2014-09-15

    Sulfur is essential in all organisms for the synthesis of amino acids cysteine and methionine and as an active component of numerous co-factors and prosthetic groups. However, only plants, algae, fungi, and some prokaryotes are capable of using the abundant inorganic source of sulfur, sulfate. Plants take sulfate up, reduce it, and assimilate into organic compounds with cysteine being the first product of the pathway and a donor of reduced sulfur for synthesis of other S-containing compounds. Cysteine is formed in a reaction between sulfide, derived from reduction of sulfite and an activated amino acid acceptor, O-acetylserine. Sulfide is thus an important intermediate in sulfur metabolism, but numerous other functions in plants has been revealed. Hydrogen sulfide can serve as an alternative source of sulfur for plants, which may be significant in anaerobic conditions of waterlogged soils. On the other hand, emissions of hydrogen sulfide have been detected from many plant species. Since the amount of H2S discharged correlated with sulfate supply to the plants, the emissions were considered a mechanism for dissipation of excess sulfur. Significant hydrogen sulfide emissions were also observed in plants infected with pathogens, particularly with fungi. H2S thus seems to be part of the widely discussed sulfur-induced-resistance/sulfur-enhanced-defense. Recently, however, more evidence has emerged for a role for H2S in regulation and signaling. Sulfide stabilizes the cysteine synthase complex, increasing so the synthesis of its acceptor O-acetylserine. H2S has been implicating in regulation of plant stress response, particularly draught stress. There are more and more examples of processes regulated by H2S in plants being discovered, and hydrogen sulfide is emerging as an important signaling molecule, similar to its role in the animal and human world. How similar the functions, and homeostasis of H2S are in these diverse organisms, however, remains to be elucidated.

  6. The effect of hydrogen sulfide donors on lipopolysaccharide-induced formation of inflammatory mediators in macrophages.

    PubMed

    Whiteman, Matthew; Li, Ling; Rose, Peter; Tan, Choon-Hong; Parkinson, David B; Moore, Philip K

    2010-05-15

    The role of hydrogen sulfide (H(2)S) in inflammation is controversial, with both pro- and antiinflammatory effects documented. Many studies have used simple sulfide salts as the source of H(2)S, which give a rapid bolus of H(2)S in aqueous solutions and thus do not accurately reflect the enzymatic generation of H(2)S. We therefore compared the effects of sodium hydrosulfide and a novel slow-releasing H(2)S donor (GYY4137) on the release of pro- and antiinflammatory mediators in lipopolysaccharide (LPS)-treated murine RAW264.7 macrophages. For the first time, we show that GYY4137 significantly and concentration-dependently inhibits LPS-induced release of proinflammatory mediators such as IL-1beta, IL-6, TNF-alpha, nitric oxide (*NO), and PGE(2) but increased the synthesis of the antiinflammatory chemokine IL-10 through NF-kappaB/ATF-2/HSP-27-dependent pathways. In contrast, NaHS elicited a biphasic effect on proinflammatory mediators and, at high concentrations, increased the synthesis of IL-1beta, IL-6, NO, PGE(2) and TNF-alpha. This study clearly shows that the effects of H(2)S on the inflammatory process are complex and dependent not only on H(2)S concentration but also on the rate of H(2)S generation. This study may also explain some of the apparent discrepancies in the literature regarding the pro- versus antiinflammatory role of H(2)S.

  7. H2S cytotoxicity mechanism involves reactive oxygen species formation and mitochondrial depolarisation.

    PubMed

    Eghbal, Mohammad A; Pennefather, Peter S; O'Brien, Peter J

    2004-10-15

    A number of scavengers of reactive oxygen species (ROS) were found to be protective against cell death induced by hydrogen sulfide (H2S) in isolated hepatocytes. The H2O2 scavengers alpha-ketoglutarate and pyruvate, which also act as energy substrate metabolites, were more protective against H2S toxicity than lactate which is only an energy substrate metabolite. All of these results suggest that H2S toxicity is dependent on ROS production. We measured ROS formation directly in hepatocytes using the fluorogenic dichlorofluorescin method. H2S-induced ROS formation was dose dependent and pyruvate inhibited this ROS production. Non-toxic concentrations of H2S enhanced the cytotoxicity of H2O2 generated by glucose/glucose oxidase, which was inhibited by CYP450 inibitors. Furthermore, hepatocyte ROS formation induced by H2S was decreased by CYP450 inhibitors cimetidine and benzylimidazole. These results suggest that CYP450-dependant metabolism of H2S is responsible for inducing ROS production. H2S-induced cytotoxicity was preceded by mitochondrial depolarization as measured by rhodamine 123 fluorescence. Mitochondrial depolarization induced by H2S was prevented by zinc, methionine and pyruvate all of which decreased H2S-induced cell death. Treatment of H2S poisoning may benefit from interventions aimed at minimizing ROS-induced damage and reducing mitochondrial damage.

  8. Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour

    PubMed Central

    Jin, Zhuping

    2015-01-01

    Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways. PMID:26078806

  9. Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour.

    PubMed

    Jin, Zhuping; Pei, Yanxi

    2015-01-01

    Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways.

  10. Characteristics of H2S emission from aged refuse after excavation exposure.

    PubMed

    Shen, Dong-Sheng; Du, Yao; Fang, Yuan; Hu, Li-Fang; Fang, Cheng-Ran; Long, Yu-Yang

    2015-05-01

    Hydrogen sulfide (H2S(g)) emission from landfills is a widespread problem, especially when aged refuse is excavated. H2S(g) emission from aged refuse exposed to air was investigated and the results showed that large amounts of H2S(g) can be released, especially in the first few hours after excavation, when H2S(g) concentrations in air near refuse could reach 2.00 mg m(-3). Initial exposure to air did not inhibit the emission of H2S(g), as is generally assumed, but actually promoted it. The amounts of H2S(g) emitted in the first 2 d after excavation can be very dangerous, and the risks associated with the emission of H2S(g) could decrease significantly with time. Unlike a large number of sulfide existed under anaerobic conditions, the sulfide in aged municipal solid waste can be oxidized chemically to elemental sulfur (but not sulfate) under aerobic conditions, and its conversion rate was higher than 80%. Only microorganisms can oxidize the reduced sulfur species to sulfate, and the conversion rate could reach about 50%. Using appropriate techniques to enhance these chemical and biological transformations could allow the potential health risks caused by H2S(g) after refuse excavation to be largely avoided.

  11. Hydrogen Sulfide: A Therapeutic Candidate for Fibrotic Disease?

    PubMed Central

    Song, Kai; Li, Qian; Yin, Xiao-Ya; Lu, Ying; Liu, Chun-Feng; Hu, Li-Fang

    2015-01-01

    Fibrotic diseases including chronic kidney disease, liver cirrhosis, idiopathic pulmonary fibrosis, and chronic disease account for 45% mortality in the developed countries and pose a great threat to the global health. Many great targets and molecules have been reported to be involved in the initiation and/or progression of fibrosis, among which inflammation and oxidative stress are well-recognized modulation targets. Hydrogen sulfide (H2S) is the third gasotransmitter with potent properties in inhibiting inflammation and oxidative stress in various organs. Recent evidence suggests that plasma H2S level is decreased in various animal models of fibrotic diseases and supplement of exogenous H2S is able to ameliorate fibrosis in the kidney, lung, liver, and heart. This leads us to propose that modulation of H2S production may represent a promising therapeutic venue for the treatment of a variety of fibrotic diseases. Here, we summarize and discuss the current data on the role and underlying mechanisms of H2S in fibrosis diseases related to heart, liver, kidney, and other organs. PMID:26078807

  12. Endogenous hydrogen sulfide production is essential for dietary restriction benefits.

    PubMed

    Hine, Christopher; Harputlugil, Eylul; Zhang, Yue; Ruckenstuhl, Christoph; Lee, Byung Cheon; Brace, Lear; Longchamp, Alban; Treviño-Villarreal, Jose H; Mejia, Pedro; Ozaki, C Keith; Wang, Rui; Gladyshev, Vadim N; Madeo, Frank; Mair, William B; Mitchell, James R

    2015-01-15

    Dietary restriction (DR) without malnutrition encompasses numerous regimens with overlapping benefits including longevity and stress resistance, but unifying nutritional and molecular mechanisms remain elusive. In a mouse model of DR-mediated stress resistance, we found that sulfur amino acid (SAA) restriction increased expression of the transsulfuration pathway (TSP) enzyme cystathionine γ-lyase (CGL), resulting in increased hydrogen sulfide (H2S) production and protection from hepatic ischemia reperfusion injury. SAA supplementation, mTORC1 activation, or chemical/genetic CGL inhibition reduced H2S production and blocked DR-mediated stress resistance. In vitro, the mitochondrial protein SQR was required for H2S-mediated protection during nutrient/oxygen deprivation. Finally, TSP-dependent H2S production was observed in yeast, worm, fruit fly, and rodent models of DR-mediated longevity. Together, these data are consistent with evolutionary conservation of TSP-mediated H2S as a mediator of DR benefits with broad implications for clinical translation. PAPERFLICK: Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Hydrogen sulfide as a potent cardiovascular protective agent.

    PubMed

    Yu, Xiao-Hua; Cui, Li-Bao; Wu, Kai; Zheng, Xi-Long; Cayabyab, Francisco S; Chen, Zhi-Wei; Tang, Chao-Ke

    2014-11-01

    Hydrogen sulfide (H2S) is a well-known toxic gas with the characteristic smell of rotten eggs. It is synthesized endogenously in mammals from the sulfur-containing amino acid l-cysteine by the action of several distinct enzymes: cystathionine-γ-lyase (CSE), cystathionine-ß-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST) along with cysteine aminotransferase (CAT). In particular, CSE is considered to be the major H2S-producing enzyme in the cardiovascular system. As the third gasotransmitter next to nitric oxide (NO) and carbon monoxide (CO), H2S plays an important role in the regulation of vasodilation, angiogenesis, inflammation, oxidative stress and apoptosis. Growing evidence has demonstrated that this gas exerts a significant protective effect against the progression of cardiovascular diseases by a number of mechanisms such as vasorelaxation, inhibition of cardiovascular remodeling and resistance to form foam cells. The aim of this review is to provide an overview of the physiological functions of H2S and its protection against several major cardiovascular diseases, and to explore its potential health and therapeutic benefits. A better understanding will help develop novel H2S-based therapeutic interventions for these diseases.

  14. Hydrogen Sulfide Induced Disruption of Na+ Homeostasis in the Cortex

    PubMed Central

    Chao, Dongman; He, Xiaozhou; Yang, Yilin; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H.; Xia, Ying

    2012-01-01

    Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H2S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na+ activity using Na+ selective electrodes in mouse cortical slices that H2S donor sodium hydrosulfide (NaHS) increased Na+ influx in a concentration-dependent manner. This effect could be partially blocked by either Na+ channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H2S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na+ influx through Na+ channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na+ currents/influx in normoxia, had no effect on H2S-induced Na+ influx, suggesting that H2S-induced disruption of Na+ homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia. PMID:22474073

  15. Endogenous Hydrogen Sulfide Production Is Essential for Dietary Restriction Benefits

    PubMed Central

    Hine, Christopher; Harputlugil, Eylul; Zhang, Yue; Ruckenstuhl, Christoph; Lee, Byung Cheon; Brace, Lear; Longchamp, Alban; Trevino-Villarreal, Jose H.; Mejia, Pedro; Ozaki, C. Keith; Wang, Rui; Gladyshev, Vadim N.; Madeo, Frank; Mair, William B.; Mitchell, James R.

    2014-01-01

    Summary Dietary restriction (DR) without malnutrition encompasses numerous regimens with overlapping benefits including longevity and stress resistance, but unifying nutritional and molecular mechanisms remain elusive. In a mouse model of DR-mediated stress resistance, we found that sulfur amino acid (SAA) restriction increased expression of the transsulfuration pathway (TSP) enzyme cystathionine γ-lyase (CGL), resulting in increased hydrogen sulfide (H2S) production and protection from hepatic ischemia reperfusion injury. SAA supplementation, mTORC1 activation, or chemical/genetic CGL inhibition reduced H2S production and blocked DR-mediated stress resistance. In vitro, the mitochondrial protein SQR was required for H2S-mediated protection during nutrient/oxygen deprivation. Finally, TSP-dependent H2S production was observed in yeast, worm, fruit fly and rodent models of DR-mediated longevity. Together, these data are consistent with evolutionary conservation of TSP-mediated H2S as a novel mediator of DR benefits with broad implications for clinical translation. PMID:25542313

  16. Colorimetric detection of endogenous hydrogen sulfide production in living cells

    NASA Astrophysics Data System (ADS)

    Ahn, Yong Jin; Lee, Young Ju; Lee, Jaemyeon; Lee, Doyeon; Park, Hun-Kuk; Lee, Gi-Ja

    2017-04-01

    Hydrogen sulfide (H2S) has received great attention as a third gaseous signal transmitter, following nitric oxide and carbon monoxide. In particular, H2S plays an important role in the regulation of cancer cell biology. Therefore, the detection of endogenous H2S concentrations within biological systems can be helpful to understand the role of gasotransmitters in pathophysiology. Although a simple and inexpensive method for the detection of H2S has been developed, its direct and precise measurement in living cells remains a challenge. In this study, we introduced a simple, facile, and inexpensive colorimetric system for selective H2S detection in living cells using a silver-embedded Nafion/polyvinylpyrrolidone (PVP) membrane. This membrane could be easily applied onto a polystyrene microplate cover. First, we optimized the composition of the coating membrane, such as the PVP/Nafion mixing ratio and AgNO3 concentration, as well as the pH of the Na2S (H2S donor) solution and the reaction time. Next, the in vitro performance of a colorimetric detection assay utilizing the silver/Nafion/PVP membrane was evaluated utilizing a known concentration of Na2S standard solution both at room temperature and at 37 °C in a 5% CO2 incubator. As a result, the sensitivity of the colorimetric assay for H2S at 37 °C in the incubator (0.0056 Abs./μM Na2S, R2 = 0.9948) was similar to that at room temperature (0.0055 Abs./μM Na2S, R2 = 0.9967). Moreover, these assays were less sensitive to interference from compounds such as glutathione, L-cysteine (Cys), and dithiothreitol than to the H2S from Na2S. This assay based on the silver/Nafion/PVP membrane also showed excellent reproducibility (2.8% RSD). Finally, we successfully measured the endogenous H2S concentrations in live C6 glioma cells by s-(5‧-adenosyl)-L-methionine stimulation with and without Cys and L-homocysteine, utilizing the silver/Nafion/PVP membrane. In summary, colorimetric assays using silver

  17. Water vapor inhibits hydrogen sulfide detection in pulsed fluorescence sulfur monitors

    NASA Astrophysics Data System (ADS)

    Bluhme, Anders B.; Ingemar, Jonas L.; Meusinger, Carl; Johnson, Matthew S.

    2016-06-01

    The Thermo Scientific 450 Hydrogen Sulfide-Sulfur Dioxide Analyzer measures both hydrogen sulfide (H2S) and sulfur dioxide (SO2). Sulfur dioxide is measured by pulsed fluorescence, while H2S is converted to SO2 with a molybdenum catalyst prior to detection. The 450 is widely used to measure ambient concentrations, e.g., for emissions monitoring and pollution control. An air stream with a constant H2S concentration was generated and the output of the analyzer recorded as a function of relative humidity (RH). The analyzer underreported H2S as soon as the relative humidity was increased. The fraction of undetected H2S increased from 8.3 at 5.3 % RH (294 K) to over 34 % at RH > 80 %. Hydrogen sulfide mole fractions of 573, 1142, and 5145 ppb were tested. The findings indicate that previous results obtained with instruments using similar catalysts should be re-evaluated to correct for interference from water vapor. It is suspected that water decreases the efficiency of the converter unit and thereby reduces the measured H2S concentration.

  18. Differential effects of statins on endogenous H2S formation in perivascular adipose tissue.

    PubMed

    Wójcicka, Grażyna; Jamroz-Wiśniewska, Anna; Atanasova, Pepa; Chaldakov, George N; Chylińska-Kula, Beata; Bełtowski, Jerzy

    2011-01-01

    Hydrogen sulfide (H(2)S) is a new gasotransmitter synthesized enzymatically from l-cysteine in cytosol and is oxidized in mitochondria. In the cardiovascular system, H(2)S regulates vascular tone, inhibits atherogenesis, and protects against myocardial ischemia-reperfusion injury. We examined the effect of statins on vascular H(2)S production. Male Wistar rats received pravastatin (40mg/kg/day) or atorvastatin (20mg/kg/day) for 3 weeks and then H(2)S formation was measured in aortic media, periaortic adipose tissue (PAAT) and the liver. Only atorvastatin increased H(2)S production in PAAT whereas both statins stimulated its formation in the liver. Neither statin affected H(2)S production in aortic media. H(2)S formation in post-mitochondrial supernatant was higher than in mitochondria-containing supernatant and was not influenced by statins in any tissue. In addition, oxidation of exogenous H(2)S in isolated liver mitochondria was slower in statin-treated than in control rats. These data indicate that statins increase net H(2)S production by inhibiting its mitochondrial oxidation. Statins had no effect on the activity of H(2)S-metabolizing enzyme, sulfide:quinone oxidoreductase, measured at saturating coenzyme Q concentration. Both statins reduced CoQ(9) concentration in plasma and liver, but only atorvastatin decreased CoQ(9) in PAAT. Atorvastatin attenuated phenylephrine-induced contraction of PAAT+ but not of PAAT- aortic rings. Effects of atorvastatin on net H(2)S production, mitochondrial H(2)S oxidation and aortic contractility were abolished by supplementation of exogenous CoQ(9). In conclusion, lipophilic atorvastatin, but not hydrophilic pravastatin, increases net H(2)S production in perivascular adipose tissue by inhibiting its mitochondrial oxidation. This effect is mediated by statin-induced CoQ(9) deficiency and results in the augmentation of anticontractile effect of perivascular adipose tissue.

  19. A solid oxide fuel cell system fed with hydrogen sulfide and natural gas

    NASA Astrophysics Data System (ADS)

    Lu, Yixin; Schaefer, Laura

    Hydrogen sulfide (H 2S) occurs naturally in crude petroleum, natural gas, volcanic gases, hot springs, and some lakes. Hydrogen sulfide can also result as a by-product from industrial activities, such as food processing, coke ovens, paper mills, tanneries, and petroleum refineries. Sometimes, it is considered to be an industrial pollutant. However, hydrogen can be decomposed from H 2S and then used as fuel for a solid oxide fuel cell (SOFC). This paper presents an examination of a simple hydrogen sulfide and natural gas-fed solid oxide fuel cell system. The possibility of utilization of hydrogen sulfide as a feedstock in a solid oxide fuel cell is discussed. A system configuration of an SOFC combined with an external H 2S decomposition device is proposed, where a certain amount of natural gas is supplied to the SOFC. The exhaust fuel gas of the SOFC is after-burned with exhaust air from the SOFC, and the heat of the combustion gas is utilized in the decomposition of H 2S in a decomposition reactor (DR) to produce hydrogen to feed the SOFC. The products are electricity and industry-usable sulfur. Through a mass and energy balance, a preliminary thermodynamic analysis of this system is performed, and the system efficiency is calculated. Also in this paper, the challenges in creating the proposed configuration are discussed, and the direction of future work is presented.

  20. Hydrogen sulfide deactivates common nitrobenzofurazan-based fluorescent thiol labeling reagents.

    PubMed

    Montoya, Leticia A; Pluth, Michael D

    2014-06-17

    Sulfhydryl-containing compounds, including thiols and hydrogen sulfide (H2S), play important but differential roles in biological structure and function. One major challenge in separating the biological roles of thiols and H2S is developing tools to effectively separate the reactivity of these sulfhydryl-containing compounds. To address this challenge, we report the differential responses of common electrophilic fluorescent thiol labeling reagents, including nitrobenzofurazan-based scaffolds, maleimides, alkylating agents, and electrophilic aldehydes, toward cysteine and H2S. Although H2S reacted with all of the investigated scaffolds, the photophysical response to each scaffold was significantly different. Maleimide-based, alkylating, and aldehydic thiol labeling reagents provided a diminished fluorescence response when treated with H2S. By contrast, nitrobenzofurazan-based labeling reagents were deactivated by H2S addition. Furthermore, the addition of H2S to thiol-activated nitrobenzofurazan-based reagents reduced the fluorescence signal, thus establishing the incompatibility of nitrobenzofurazan-based thiol labeling reagents in the presence of H2S. Taken together, these studies highlight the differential reactivity of thiols and H2S toward common thiol-labeling reagents and suggest that sufficient care must be taken when labeling or measuring thiols in cellular environments that produce H2S due to the potential for both false-positive and eroded responses.

  1. Hydrogen sulfide lowers proliferation and induces protective autophagy in colon epithelial cells.

    PubMed

    Wu, Ya C; Wang, Xiao J; Yu, Le; Chan, Francis K L; Cheng, Alfred S L; Yu, Jun; Sung, Joseph J Y; Wu, William K K; Cho, Chi H

    2012-01-01

    Hydrogen sulfide (H(2)S) is a gaseous bacterial metabolite that reaches high levels in the large intestine. In the present study, the effect of H(2)S on the proliferation of normal and cancerous colon epithelial cells was investigated. An immortalized colon epithelial cell line (YAMC) and a panel of colon cancer cell lines (HT-29, SW1116, HCT116) were exposed to H(2)S at concentrations similar to those found in the human colon. H(2)S inhibited normal and cancerous colon epithelial cell proliferation as measured by MTT assay. The anti-mitogenic effect of H(2)S was accompanied by G(1)-phase cell cycle arrest and the induction of the cyclin-dependent kinase inhibitor p21(Cip). Moreover, exposure to H(2)S led to features characteristic of autophagy, including increased formation of LC3B(+) autophagic vacuoles and acidic vesicular organelles as determined by immunofluorescence and acridine orange staining, respectively. Abolition of autophagy by RNA interference targeting Vps34 or Atg7 enhanced the anti-proliferative effect of H(2)S. Further mechanistic investigation revealed that H(2)S stimulated the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and S6 kinase. Inhibition of AMPK significantly reversed H(2)S-induced autophagy and inhibition of cell proliferation. Collectively, we demonstrate that H(2)S inhibits colon epithelial cell proliferation and induces protective autophagy via the AMPK pathway.

  2. Hydrogen Sulfide Deactivates Common Nitrobenzofurazan-Based Fluorescent Thiol Labeling Reagents

    PubMed Central

    2015-01-01

    Sulfhydryl-containing compounds, including thiols and hydrogen sulfide (H2S), play important but differential roles in biological structure and function. One major challenge in separating the biological roles of thiols and H2S is developing tools to effectively separate the reactivity of these sulfhydryl-containing compounds. To address this challenge, we report the differential responses of common electrophilic fluorescent thiol labeling reagents, including nitrobenzofurazan-based scaffolds, maleimides, alkylating agents, and electrophilic aldehydes, toward cysteine and H2S. Although H2S reacted with all of the investigated scaffolds, the photophysical response to each scaffold was significantly different. Maleimide-based, alkylating, and aldehydic thiol labeling reagents provided a diminished fluorescence response when treated with H2S. By contrast, nitrobenzofurazan-based labeling reagents were deactivated by H2S addition. Furthermore, the addition of H2S to thiol-activated nitrobenzofurazan-based reagents reduced the fluorescence signal, thus establishing the incompatibility of nitrobenzofurazan-based thiol labeling reagents in the presence of H2S. Taken together, these studies highlight the differential reactivity of thiols and H2S toward common thiol-labeling reagents and suggest that sufficient care must be taken when labeling or measuring thiols in cellular environments that produce H2S due to the potential for both false-positive and eroded responses. PMID:24852143

  3. Hydrogen sulfide-based therapeutics and gastrointestinal diseases: translating physiology to treatments.

    PubMed

    Chan, Melissa V; Wallace, John L

    2013-10-01

    Hydrogen sulfide (H2S) is a gaseous meditator that has various physiological and pathophysiological roles in the body. It has been shown to be an important mediator of gastrointestinal (GI) mucosal defense and contributes significantly to repair of damage and resolution of inflammation. Synthesis of H2S increases markedly after mucosal injury, and inhibition of H2S in such circumstances leads to delayed healing and exacerbated inflammation. The beneficial effects of H2S may be attributable to its ability to elevate mucosal blood flow, prevent leukocyte-endothelial adhesion, reduce oxidative stress, and stimulate angiogenesis. The use of H2S-donating agents and inhibitors of the key enzymes contributing to H2S synthesis have provided strong evidence for the importance of H2S in enhancing mucosal resistance to damage, as well as modulating inflammation and repair. In recent years, significant evidence has been generated to support the notion that these positive aspects of H2S can be exploited in drug design, particularly for arthritis, inflammatory bowel disease, and colon cancer chemoprevention. Thus novel H2S-based therapies have been shown to be effective anti-inflammatories that can promote the resolution of inflammation and accelerate the healing of GI ulcers. Encouraging results have already been seen experimentally with a mesalamine derivative and with H2S-releasing derivatives of nonsteroidal anti-inflammatory drugs.

  4. Protein S-sulfhydration by hydrogen sulfide in cardiovascular system.

    PubMed

    Meng, Guoliang; Zhao, Shuang; Xie, Liping; Han, Yi; Ji, Yong

    2017-04-22

    Hydrogen sulfide (H2 S), independently of any specific transporters, has a number of biological effects on the cardiovascular system. However, until now, the detailed mechanism of H2 S was not clear. Recently, a novel post-translational modification induced by H2 S, named S-sulfhydration, has been proposed. S-sulfhydration is the chemical modification of specific cysteine residues of target proteins by H2 S. There are several methods for detecting S-sulfhydration, such as the modified biotin switch assay, maleimide assay with fluorescent thiol modifying regents, tag-switch method and mass spectrometry. H2 S induces S-sulfhydration on enzymes or receptors (such as p66Shc, phospholamban, protein tyrosine phosphatase 1B, mitogen-activated extracellular signal-regulated kinase 1 and ATP synthase subunit α), transcription factors (such as specific protein-1, kelch-like ECH-associating protein 1, NF-κB and interferon regulatory factor-1), and ion channels (such as voltage-activated Ca(2+) channels, transient receptor potential channels and ATP-sensitive K(+) channels) in the cardiovascular system. Although significant progress has been achieved in delineating the role of protein S-sulfhydration by H2 S in the cardiovascular system, more proteins with detailed cysteine sites of S-sulfhydration as well as physiological function need to be investigated in further studies. This review mainly summarizes the role and possible mechanism of S-sulfhydration in the cardiovascular system. The S-sulfhydrated proteins may be potential novel targets for therapeutic intervention and drug design in the cardiovascular system, which may accelerate the development and application of H2 S-related drugs in the future. © 2017 The British Pharmacological Society.

  5. Hydrogen sulfide promotes calcium uptake in larval zebrafish.

    PubMed

    Kwong, Raymond W M; Perry, Steve F

    2015-07-01

    Hydrogen sulfide (H2S) can act as a signaling molecule for various ion channels and/or transporters; however, little is known about its potential involvement in Ca(2+) balance. Using developing zebrafish (Danio rerio) as an in vivo model system, the present study demonstrated that acute exposure to H2S donors increased Ca(2+) influx at 4 days postfertilization, while chronic (3-day) exposure caused a rise in whole body Ca(2+) levels. The mRNA expression of Ca(2+)-transport-related genes was unaffected by H2S exposure, suggesting that posttranscriptional modifications were responsible for the altered rates of Ca(2+) uptake. Indeed, treatment of fish with the protein kinase A inhibitor H-89 abolished the H2S-mediated stimulation of Ca(2+) influx, suggesting that H2S increased Ca(2+) influx by activating cAMP-protein kinase A pathways. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are two key enzymes in the endogenous synthesis of H2S. Using an antisense morpholino knockdown approach, we demonstrated that Ca(2+) influx was reduced in CBS isoform b (CBSb)- but not in CSE-deficient fish. Interestingly, the reduction in Ca(2+) influx in CBSb-deficient fish was observed only in fish that were acclimated to low-Ca(2+) water (i.e., 25 μM Ca(2+); control: 250 μM Ca(2+)). Similarly, mRNA expression of cbsb but not cse was increased in fish acclimated to low-Ca(2+) water. Results from whole-mount immunohistochemistry further revealed that CBSb was expressed in Na(+)-K(+)-ATPase-rich cells, which are implicated in Ca(2+) uptake in zebrafish larvae. Collectively, the present study suggests a novel role for H2S in promoting Ca(2+) influx, particularly in a low-Ca(2+) environment.

  6. Role of hydrogen sulfide in skeletal muscle biology and metabolism

    PubMed Central

    Veeranki, Sudhakar; Tyagi, Suresh C.

    2014-01-01

    Hydrogen sulfide (H2S) is a novel endogenous gaseous signal transducer (gasotransmittor). Its emerging role in multiple facets of inter- and intra-cellular signaling as a metabolic, inflammatory, neuro and vascular modulator has been increasingly realized. Although H2S is known for its effects as an anti-hypertensive, anti-inflammatory and anti-oxidant molecule, the relevance of these effects in skeletal muscle biology during health and during metabolic syndromes is unclear. H2S has been implicated in vascular relaxation and vessel tone enhancement, which might lead to mitigation of vascular complications caused by the metabolic syndromes. Metabolic complications may also lead to mitochondrial remodeling by interfering with fusion and fission, therefore, leading to mitochondrial mitophagy and skeletal muscle myopathy. Mitochondrial protection by H2S enhancing treatments may mitigate deterioration of muscle function during metabolic syndromes. In addition, H2S might upregulate uncoupling proteins and might also cause browning of white fat, resulting in suppression of imbalanced cytokine signaling caused by abnormal fat accumulation. Likewise, as a source for H+ ions, it has the potential to augment anaerobic ATP synthesis. However, there is a need for studies to test these putative H2S benefits in different patho-physiological scenarios before its full-fledged usage as a therapeutic molecule. The present review highlights current knowledge with regard to exogenous and endogenous H2S roles in skeletal muscle biology, metabolism, exercise physiology and related metabolic disorders, such as diabetes and obesity, and also provides future directions. PMID:25461301

  7. Hydrogen sulfide promotes calcium uptake in larval zebrafish

    PubMed Central

    Perry, Steve F.

    2015-01-01

    Hydrogen sulfide (H2S) can act as a signaling molecule for various ion channels and/or transporters; however, little is known about its potential involvement in Ca2+ balance. Using developing zebrafish (Danio rerio) as an in vivo model system, the present study demonstrated that acute exposure to H2S donors increased Ca2+ influx at 4 days postfertilization, while chronic (3-day) exposure caused a rise in whole body Ca2+ levels. The mRNA expression of Ca2+-transport-related genes was unaffected by H2S exposure, suggesting that posttranscriptional modifications were responsible for the altered rates of Ca2+ uptake. Indeed, treatment of fish with the protein kinase A inhibitor H-89 abolished the H2S-mediated stimulation of Ca2+ influx, suggesting that H2S increased Ca2+ influx by activating cAMP-protein kinase A pathways. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are two key enzymes in the endogenous synthesis of H2S. Using an antisense morpholino knockdown approach, we demonstrated that Ca2+ influx was reduced in CBS isoform b (CBSb)- but not in CSE-deficient fish. Interestingly, the reduction in Ca2+ influx in CBSb-deficient fish was observed only in fish that were acclimated to low-Ca2+ water (i.e., 25 μM Ca2+; control: 250 μM Ca2+). Similarly, mRNA expression of cbsb but not cse was increased in fish acclimated to low-Ca2+ water. Results from whole-mount immunohistochemistry further revealed that CBSb was expressed in Na+-K+-ATPase-rich cells, which are implicated in Ca2+ uptake in zebrafish larvae. Collectively, the present study suggests a novel role for H2S in promoting Ca2+ influx, particularly in a low-Ca2+ environment. PMID:25948733

  8. Role of hydrogen sulfide in skeletal muscle biology and metabolism.

    PubMed

    Veeranki, Sudhakar; Tyagi, Suresh C

    2015-04-30

    Hydrogen sulfide (H2S) is a novel endogenous gaseous signal transducer (gasotransmitter). Its emerging role in multiple facets of inter- and intra-cellular signaling as a metabolic, inflammatory, neuro and vascular modulator has been increasingly realized. Although H2S is known for its effects as an anti-hypertensive, anti-inflammatory and anti-oxidant molecule, the relevance of these effects in skeletal muscle biology during health and during metabolic syndromes is unclear. H2S has been implicated in vascular relaxation and vessel tone enhancement, which might lead to mitigation of vascular complications caused by the metabolic syndromes. Metabolic complications may also lead to mitochondrial remodeling by interfering with fusion and fission, therefore, leading to mitochondrial mitophagy and skeletal muscle myopathy. Mitochondrial protection by H2S enhancing treatments may mitigate deterioration of muscle function during metabolic syndromes. In addition, H2S might upregulate uncoupling proteins and might also cause browning of white fat, resulting in suppression of imbalanced cytokine signaling caused by abnormal fat accumulation. Likewise, as a source for H(+) ions, it has the potential to augment anaerobic ATP synthesis. However, there is a need for studies to test these putative H2S benefits in different patho-physiological scenarios before its full-fledged usage as a therapeutic molecule. The present review highlights current knowledge with regard to exogenous and endogenous H2S roles in skeletal muscle biology, metabolism, exercise physiology and related metabolic disorders, such as diabetes and obesity, and also provides future directions. Published by Elsevier Inc.

  9. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

    PubMed Central

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2 ∙−) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation. PMID:27594971

  10. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses.

    PubMed

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui; Wei, Zhao-Jun; Zhang, Hua

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2 (∙-)) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation.

  11. Production of Hydrogen Sulfide by Streptomycetes and Methods for its Detection

    PubMed Central

    Küster, E.; Williams, S. T.

    1964-01-01

    The ability of streptomycetes to produce hydrogen sulfide is generally used for taxonomic purposes. It was found that the previously used method, the blackening of Peptone Iron Agar, does not clearly indicate formation of hydrogen sulfide. It was shown that the blackening of a lead acetate strip is the most accurate indicator for H2S-producing streptomycetes. A great variety of organic and inorganic sulfur compounds were examined and compared, and the choice of the most suitable sulfur source and method for the detection of hydrogen sulfide is discussed. PMID:14106940

  12. PRODUCTION OF HYDROGEN SULFIDE BY STREPTOMYCETES AND METHODS FOR ITS DETECTION.

    PubMed

    KUESTER, E; WILLIAMS, S T

    1964-01-01

    The ability of streptomycetes to produce hydrogen sulfide is generally used for taxonomic purposes. It was found that the previously used method, the blackening of Peptone Iron Agar, does not clearly indicate formation of hydrogen sulfide. It was shown that the blackening of a lead acetate strip is the most accurate indicator for H(2)S-producing streptomycetes. A great variety of organic and inorganic sulfur compounds were examined and compared, and the choice of the most suitable sulfur source and method for the detection of hydrogen sulfide is discussed.

  13. Evaluation of thiosulfate as a substitute for hydrogen sulfide in sour corrosion fatigue studies

    NASA Astrophysics Data System (ADS)

    Kappes, Mariano Alberto

    This work evaluates the possibility of replacing hydrogen sulfide (H 2S) with thiosulfate anion (S2O32- ) in sour corrosion fatigue studies. H2S increases the corrosion fatigue crack growth rate (FCGR) and can be present in carbon steel risers and flowlines used in off-shore oil production. Corrosion tests with gaseous H2S require special facilities with safety features, because H2S is a toxic and flammable gas. The possibility of replacing H2S with S2O32-, a non-toxic anion, for studying stress corrosion cracking of stainless and carbon steels in H2S solutions was first proposed by Tsujikawa et al. ( Tsujikawa et al., Corrosion, 1993. 49(5): p. 409-419). In this dissertation, Tsujikawa work will be extended to sour corrosion fatigue of carbon steels. H2S testing is often conducted in deareated condition to avoid oxygen reaction with sulfide that yields sulfur and to mimic oil production conditions. Nitrogen deareation was also adopted in S2O3 2- testing, and gas exiting the cell was forced through a sodium hydroxide trap. Measurements of the sulfide content of this trap were used to estimate the partial pressure of H2S in nitrogen, and Henry's law was used to estimate the content of H2S in the solution in the cell. H2S was produced by a redox reaction of S2O 32-, which required electrons from carbon steel corrosion. This reaction is spontaneous at the open circuit potential of steel. Therefore, H2S concentration was expected to be maximum at the steel surface, and this concentration was estimated by a mass balance analysis. Carbon steel specimens exposed to S2O32- containing solutions developed a film on their surface, composed by iron sulfide and cementite. The film was not passivating and a good conductor of electrons. Hydrogen permeation experiments proved that this film controls the rate of hydrogen absorption of steels exposed to thiosulfate containing solutions. The absorption of hydrogen in S2O3 2- solutions was compared with the absorption of hydrogen in

  14. Hydrogen Sulfide Signaling Axis as a Target for Prostate Cancer Therapeutics

    PubMed Central

    Liu, Mingzhe; Wu, Lingyun; Montaut, Sabine; Yang, Guangdong

    2016-01-01

    Hydrogen sulfide (H2S) was originally considered toxic at elevated levels; however just in the past decade H2S has been proposed to be an important gasotransmitter with various physiological and pathophysiological roles in the body. H2S can be generated endogenously from L-cysteine by multiple enzymes, including cystathionine gamma-lyase, cystathionine beta-synthase, and 3-mercaptopyruvate sulfurtransferase in combination with cysteine aminotransferase. Prostate cancer is a major health concern and no effective treatment for prostate cancers is available. H2S has been shown to inhibit cell survival of androgen-independent, androgen-dependent, and antiandrogen-resistant prostate cancer cells through different mechanisms. Various H2S-releasing compounds, including sulfide salts, diallyl disulfide, diallyl trisulfide, sulforaphane, and other polysulfides, also have been shown to inhibit prostate cancer growth and metastasis. The expression of H2S-producing enzyme was reduced in both human prostate cancer tissues and prostate cancer cells. Androgen receptor (AR) signaling is indispensable for the development of castration resistant prostate cancer, and H2S was shown to inhibit AR transactivation and contributes to antiandrogen-resistant status. In this review, we summarized the current knowledge of H2S signaling in prostate cancer and described the molecular alterations, which may bring this gasotransmitter into the clinic in the near future for developing novel pharmacological and therapeutic interventions for prostate cancer. PMID:27019751

  15. Impact of fermentation rate changes on potential hydrogen sulfide concentrations in wine.

    PubMed

    Butzke, Christian E; Park, Seung Kook

    2011-05-01

    The correlation between alcoholic fermentation rate, measured as carbon dioxide (CO2) evolution, and the rate of hydrogen sulfide (H2S) formation during wine production was investigated. Both rates and the resulting concentration peaks in fermentor headspace H2S were directly impacted by yeast assimilable nitrogenous compounds in the grape juice. A series of model fermentations was conducted in temperature-controlled and stirred fermentors using a complex model juice with defined concentrations of ammonium ions and/or amino acids. The fermentation rate was measured indirectly by noting the weight loss of the fermentor; H2S was quantitatively trapped in realtime using a pre-calibrated H2S detection tube which was inserted into a fermentor gas relief port. Evolution rates for CO2 and H2S as well as the relative ratios between them were calculated. These fermentations confirmed that total sulfide formation was strongly yeast strain-dependent, and high concentrations of yeast assimilable nitrogen did not necessarily protect against elevated H2S formation. High initial concentrations of ammonium ions via addition of diammonium phosphate (DAP) caused a higher evolution of H2S when compared with a non-supplemented but nondeficient juice. It was observed that the excess availability of a certain yeast assimilable amino acid, arginine, could result in a more sustained CO2 production rate throughout the wine fermentation. The contribution of yeast assimilable amino acids from conventional commercial yeast foods to lowering of the H2S formation was marginal.

  16. The hydrogen sulfide emissions abatement program at the Geysers Geothermal Power Plant

    NASA Technical Reports Server (NTRS)

    Allen, G. W.; Mccluer, H. K.

    1974-01-01

    The scope of the hydrogen sulfide (H2S) abatement program at The Geysers Geothermal Power Plant and the measures currently under way to reduce these emissions are discussed. The Geysers steam averages 223 ppm H2S by weight and after passing through the turbines leaves the plant both through the gas ejector system and by air-stripping in the cooling towers. The sulfide dissolved in the cooling water is controlled by the use of an oxidation catalyst such as an iron salt. The H2S in the low Btu ejector off gases may be burned to sulfur dioxide and scrubbed directly into the circulating water and reinjected into the steam field with the excess condensate. Details are included concerning the disposal of the impure sulfur, design requirements for retrofitting existing plants and modified plant operating procedures. Discussion of future research aimed at improving the H2S abatement system is also included.

  17. Inhibition of hydrogen sulfide biosynthesis sensitizes lung adenocarcinoma to chemotherapeutic drugs by inhibiting mitochondrial DNA repair and suppressing cellular bioenergetics

    PubMed Central

    Szczesny, Bartosz; Marcatti, Michela; Zatarain, John R.; Druzhyna, Nadiya; Wiktorowicz, John E.; Nagy, Péter; Hellmich, Mark R.; Szabo, Csaba

    2016-01-01

    Therapeutic manipulation of the gasotransmitter hydrogen sulfide (H2S) has recently been proposed as a novel targeted anticancer approach. Here we show that human lung adenocarcinoma tissue expresses high levels of hydrogen sulfide (H2S) producing enzymes, namely, cystathionine beta-synthase (CBS), cystathionine gamma lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST), in comparison to adjacent lung tissue. In cultured lung adenocarcinoma but not in normal lung epithelial cells elevated H2S stimulates mitochondrial DNA repair through sulfhydration of EXOG, which, in turn, promotes mitochondrial DNA repair complex assembly, thereby enhancing mitochondrial DNA repair capacity. In addition, inhibition of H2S-producing enzymes suppresses critical bioenergetics parameters in lung adenocarcinoma cells. Together, inhibition of H2S-producing enzymes sensitize lung adenocarcinoma cells to chemotherapeutic agents via induction of mitochondrial dysfunction as shown in in vitro and in vivo models, suggesting a novel mechanism to overcome tumor chemoresistance. PMID:27808278

  18. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci

    PubMed Central

    Ooi, Xi Jia

    2016-01-01

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora. PMID:26801579

  19. Brain, Learning, and Memory: Role of H2S in Neurodegenerative Diseases.

    PubMed

    Nagpure, B V; Bian, Jin-Song

    2015-01-01

    For more than 300 years, the toxicity of hydrogen sulfide (H2S) has been known to mankind. However, this point of view is changing as an increased interest was observed in H2S biology in the last two decades. The scientific community has succeeded to unravel many important physiological and pathological effects of H2S on mammalian body systems. Thus, H2S is now referred to as a third endogenous gaseous mediator along with nitric oxide and carbon monoxide. Acting as a neuromodulator, H2S facilitates long-term potentiation and regulates intracellular calcium levels, which are important processes in learning and memory. Aberrant endogenous production and metabolism of H2S are implicated in pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD). Various H2S donors have shown beneficial therapeutic effects in neurodegenerative disease models by targeting hallmark pathological events (e.g., amyloid-β production in AD and neuroinflammation in PD). The results obtained from many in vivo studies clearly show that H2S not only prevents neuronal and synaptic deterioration but also improves deficits in memory, cognition, and learning. The anti-inflammatory, antioxidant, and anti-apoptotic effects of H2S underlie its neuroprotective properties. In this chapter, we will overview the current understanding of H2S in context of neurodegenerative diseases, with special emphasis on its corrective effects on impaired learning, memory, and cognition.

  20. Medicinal Chemistry: Insights into the Development of Novel H2S Donors.

    PubMed

    Zhao, Yu; Pacheco, Armando; Xian, Ming

    2015-01-01

    Hydrogen sulfide (H2S) was traditionally considered as a toxic gas. However, recent studies have demonstrated H2S is an endogenously generated gaseous signaling molecule (gasotransmitter) with importance on par with that of two other well-known endogenous gasotransmitters, nitric oxide (NO) and carbon monoxide (CO). Although H2S's exact mechanisms of action are still under investigation, the production of endogenous H2S and the exogenous administration of H2S have been demonstrated to elicit a wide range of physiological responses including modulation of blood pressure and protection of ischemia reperfusion injury, exertion of anti-inflammatory effects, and reduction of metabolic rate. These results strongly suggest that modulation of H2S levels could have potential therapeutic values. In this regard, synthetic H2S-releasing agents (i.e., H2S donors) are not only important research tools, but also potential therapeutic agents. This chapter summarizes the knowledge of currently available H2S donors. Their preparation, H2S releasing mechanisms, and biological applications are discussed.

  1. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci.

    PubMed

    Ooi, Xi Jia; Tan, Kai Soo

    2016-01-22

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Two's company, three's a crowd: can H2S be the third endogenous gaseous transmitter?

    PubMed

    Wang, Rui

    2002-11-01

    Bearing the public image of a deadly "gas of rotten eggs," hydrogen sulfide (H2S) can be generated in many types of mammalian cells. Functionally, H2S has been implicated in the induction of hippocampal long-term potentiation, brain development, and blood pressure regulation. By acting specifically on KATP channels, H2S can hyperpolarize cell membranes, relax smooth muscle cells, or decrease neuronal excitability. The endogenous metabolism and physiological functions of H2S position this gas well in the novel family of endogenous gaseous transmitters, termed "gasotransmitters." It is hypothesized that H2S is the third endogenous signaling gasotransmitter, besides nitric oxide and carbon monoxide. This positioning of H2S will open an exciting field-H2S physiology-encompassing realization of the interaction of H2S and other gasotransmitters, sulfurating modification of proteins, and the functional role of H2S in multiple systems. It may shed light on the pathogenesis of many diseases related to the abnormal metabolism of H2S.

  3. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    PubMed

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  4. Hydrogen sulfide production during yeast fermentation causes the accumulation of ethanethiol, S-ethyl thioacetate and diethyl disulfide.

    PubMed

    Kinzurik, Matias I; Herbst-Johnstone, Mandy; Gardner, Richard C; Fedrizzi, Bruno

    2016-10-15

    Hydrogen sulfide (H2S) is produced by yeast during winemaking and possesses off-flavors reminiscent of rotten eggs. The production of H2S during fermentation has also been associated in the finished wine with the rise of additional volatile sulfur compounds (VSCs) with strong aromas of cooked onions and vegetables. To characterize these more complex VSCs produced from H2S, we performed fermentations in synthetic grape juice. H2S production was manipulated experimentally by feeding increasing concentrations of sulfate to mutant strains that are unable to incorporate H2S efficiently as part of the sulfur assimilation pathway. In finished wines from these mutants, three VSCs - ethanethiol, S-ethyl thioacetate and diethyl disulfide - increased proportionally to H2S. (34)S-labeled sulfate fed to the MET17-deleted strain was incorporated into same three VSCs, demonstrating that they are formed directly from H2S. Copyright © 2016. Published by Elsevier Ltd.

  5. Inflammatory effects of hypothermia and inhaled H2S during resuscitated, hyperdynamic murine septic shock.

    PubMed

    Wagner, Florian; Wagner, Katja; Weber, Sandra; Stahl, Bettina; Knöferl, Markus W; Huber-Lang, Markus; Seitz, Daniel H; Asfar, Pierre; Calzia, Enrico; Senftleben, Uwe; Gebhard, Florian; Georgieff, Michael; Radermacher, Peter; Hysa, Vladislava

    2011-04-01

    Inhaling hydrogen sulfide (H2S) reduced energy expenditure resulting in hypothermia. Because the inflammatory effects of either hypothermia alone or H2S per se still are a matter of debate, we tested the hypothesis whether inhaled H2S amplifies the hypothermia-related modulation of the inflammatory response. Fifteen hours after cecal ligation and puncture or sham laparotomy, anesthetized and mechanically ventilated normothermic and hypothermic mice (core temperature kept at 38°C and 27°C, respectively) received either 100 ppm H2S or vehicle. In the sham-operated animals, inhaled H2S and hypothermia alone comparably reduced the plasma chemokine and IL-6 levels, but combining hypothermia and inhaled H2S had no additional effect. The lung tissue cytokine and chemokine patterns revealed a similar response. During sepsis, inhaled H2S reduced the blood cytokine concentrations only, without effects on the plasma chemokine or the lung tissue levels. Again, inhaled H2S had no major additional effect during hypothermia. With or without sepsis, inhaled H2S and hypothermia alone comparably reduced the lung tissue heme oxygenase 1 expression, whereas inhaled H2S had no additional effect during hypothermia. Lung tissue nuclear transcription factor κB activation was reduced by combining H2S with hypothermia in the sham-operated animals, whereas it was increased by inhaled H2S during sepsis. Hypothermia amplified this response. Hence, during anesthesia and mechanical ventilation, inhaled H2S exerted anti-inflammatory effects, which were, however, not amplified by adding deliberate hypothermia. Sepsis attenuated these anti-inflammatory effects of inhaled H2S, which were at least in part independent of the nuclear transcription factor κB pathway.

  6. Endogenous Production of H2S in the Gastrointestinal Tract: Still in Search of a Physiologic Function

    PubMed Central

    Linden, David R.; Levitt, Michael D.; Farrugia, Gianrico

    2010-01-01

    Abstract Hydrogen sulfide (H2S) has long been associated with the gastrointestinal tract, especially the bacteria-derived H2S present in flatus. Along with evidence from other organ systems, the finding that gastrointestinal tissues are capable of endogenous production of H2S has led to the hypothesis that H2S is an endogenous gaseous signaling molecule. In this review, the criteria of gasotransmitters are reexamined, and evidence from the literature regarding H2S as a gaseous signaling molecule is discussed. H2S is produced enzymatically by gastrointestinal tissues, but evidence is lacking on whether H2S production is regulated. H2S causes well-defined physiologic effects in gastrointestinal tissues, but evidence for a receptor for H2S is lacking. H2S is inactivated through enzymatic oxidation, but evidence is lacking on whether manipulating H2S oxidation alters endogenous cell signaling. Remaining questions regarding the role of H2S as a gaseous signaling molecule in the gastrointestinal tract suggest that H2S currently remains a molecule in search of a physiologic function. Antioxid. Redox Signal. 12, 1135–1146. PMID:19769466

  7. Removal of hydrogen sulfide using palygorskite in a fixed bed adsorber.

    PubMed

    Higuchi, T; Zhang, Q; Sekine, M; Imai, T; Yamamoto, K

    2012-01-01

    This work describes the use of a novel palygorskite, a type of magnesium aluminium silicate clay possessing a high specific surface area and pore surface activity, as a low cost and highly efficient adsorbent for hydrogen sulfide (H(2)S) removal. Adsorption of H(2)S on palygorskite pretreated with acid or base was investigated in a fixed bed adsorber. The samples after base pretreatment had better dynamic adsorption performances than raw material and samples pretreated with acid. The H(2)S adsorption capacity decreased with an increase in inlet H(2)S concentration. This can be interpreted by the fact that H(2)S adsorption on the surface of palygorskite is chemisorption. The adsorption capacity increased from 25 to 50 °C, then decreased from 50 to 100 °C, which indicates that chemisorption took place and its better reaction temperature was around 50 °C.

  8. An integrated photoelectrochemical-chemical loop for solar-driven overall splitting of hydrogen sulfide.

    PubMed

    Zong, Xu; Han, Jingfeng; Seger, Brian; Chen, Hongjun; Lu, Gaoqing Max; Li, Can; Wang, Lianzhou

    2014-04-22

    Abundant and toxic hydrogen sulfide (H2 S) from industry and nature has been traditionally considered a liability. However, it represents a potential resource if valuable H2 and elemental sulfur can be simultaneously extracted through a H2 S splitting reaction. Herein a photochemical-chemical loop linked by redox couples such as Fe(2+) /Fe(3+) and I(-) /I3 (-) for photoelectrochemical H2 production and H2 S chemical absorption redox reactions are reported. Using functionalized Si as photoelectrodes, H2 S was successfully split into elemental sulfur and H2 with high stability and selectivity under simulated solar light. This new conceptual design will not only provide a possible route for using solar energy to convert H2 S into valuable resources, but also sheds light on some challenging photochemical reactions such as CH4 activation and CO2 reduction. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A highly selective fluorescent probe based on Michael addition for fast detection of hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Gao, Baozhen; Cui, Lixia; Pan, Yong; Xue, Minjie; Zhu, Boyu; Zhang, Guomei; Zhang, Caihong; Shuang, Shaomin; Dong, Chuan

    2017-02-01

    A new 4-hydroxy-1,8-naphthalimide-based compound (probe 1) has been designed and synthesized. The colorimetric and fluorescent properties of probe 1 towards hydrogen sulfide (H2S) were investigated in detail. The results show that the probe 1 could selectively and sensitively recognize H2S rather than other reactive sulfur species. The reaction mechanism of this probe is an intramolecular cyclization caused by the Michael addition of H2S to give 4-hydroxy-1,8-naphthalimide. The intramolecular charge transfer of 4-hydroxy-1,8-naphthalimide is significant. Probe 1 quickly responded to H2S and showed a 75-fold fluorescence enhancement in 5 min. Moreover, probe 1 could detect H2S quantitatively with a detection limit as low as 0.23 μM.

  10. Colorimetric detection of biological hydrogen sulfide using fluorosurfactant functionalized gold nanorods.

    PubMed

    Zhang, Xuan; Zhou, Wenjuan; Yuan, Zhiqin; Lu, Chao

    2015-11-07

    As a well-known environmental pollutant but also an important gaseous transmitter, the specific detection of hydrogen sulfide (H2S) is significant in biological systems. In this study, fluorosurfactant functionalized gold nanorods (FSN-AuNRs) have been proposed to act as selective colorimetric nanoprobes for H2S. With the combination of strong gold-S interactions and small FSN bilayer interstices, FSN-AuNRs demonstrate favorable selectivity and sensitivity toward H2S over other anions and small biological molecules. The practical application of the present method in biological H2S detection was validated with human and mouse serum samples. Moreover, the proposed nanoprobe can also be used for evaluating the activity of H2S synthetase.

  11. Postsynthetic modification of metal-organic framework for hydrogen sulfide detection

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Zhang, Jianmin; Hu, Quan; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-11-01

    Hydrogen sulfide (H2S) has recently been identified as the third biological gaseous messenger (gasotransmitter) that is involved in regulating many important physiological processes. The detection of H2S is thus essential for its roles but remain challenging in living systems. We report herein a novel turn-on fluorescent probe for H2S detection based on azide functionalized metal-organic framework (MOF). The MOF probe displayed high sensitivity (detection limit, 28.3 μM), excellent selectivity, and fast response (<2 min) toward H2S over other biologically relevant species. We envisage that this MOF probe can be employed as a useful tool to further elucidate the biological roles of H2S.

  12. H2S mediated thermal and photochemical methane activation

    PubMed Central

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric

    2013-01-01

    Sustainable, low temperature methods of natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) in mixture with methane, CH4, altogether deemed as sub-quality or “sour” gas. We propose a unique method for activating this “sour” gas to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3, and an energy carrier, such as H2. For this purpose, we computationally investigated H2S mediated methane activation to form a reactive CH3SH species via direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4+H2S complex results in a barrier-less relaxation via a conical intersection to form a ground state CH3SH+H2 complex. The resulting CH3SH can further be heterogeneously coupled over acidic catalysts to form higher hydrocarbons while the H2 can be used as a fuel. This process is very different from a conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced controllability over the process conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the currently industrially used methane steam reforming (SMR). PMID:24150813

  13. H2S-mediated thermal and photochemical methane activation.

    PubMed

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric V

    2013-12-02

    Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with methane, deemed altogether as sub-quality or "sour" gas. We propose a unique method of activation to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3 , and an energy carrier such as H2. For this purpose, we investigated the H2S-mediated methane activation to form a reactive CH3SH species by means of direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4 + H2S complex resulted in a barrierless relaxation by a conical intersection to form a ground-state CH3SH + H2 complex. The resulting CH3SH could further be coupled over acidic catalysts to form higher hydrocarbons, and the resulting H2 used as a fuel. This process is very different from conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced control over the conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the current industrial steam methane reforming (SMR).

  14. Gas-Phase Photochemical Overall H2 S Splitting by UV Light Irradiation.

    PubMed

    Baldovi, Herme G; Albero, Josep; Ferrer, Belen; Mateo, Diego; Alvaro, Mercedes; García, Hermenegildo

    2017-04-11

    Splitting of hydrogen sulfide is achieved to produce value-added chemicals. Upon irradiation at 254 nm in the gas phase and in the absence of catalysts or photocatalysts at near room temperature, H2 S splits into stoichiometric amounts of H2 and S with a quantum efficiency close to 50 %. No influence of the presence of CH4 and CO2 (typical components in natural gas and biogas in which H2 S is an unwanted component) on the efficiency of overall H2 S splitting was observed. A mechanism for the H2 and S formation is proposed.

  15. CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF PRODUCTS FROM THE REACTION OF DIMETHYLARSINIC ACID WITH HYDROGEN SULFIDE

    EPA Science Inventory

    The reaction of dimethylarsinic acid (DMAV) with hydrogen sulfide (H2S) is of biological significance and may be implicated in the overall toxicity and carcinogenicity of arsenic. The course of the reaction in aqueous phase was monitored and an initial product, dimethylthioarsin...

  16. Hydrogen sulfide and nonmethane hydrocarbon emissions from broiler houses in the Southeastern United States

    USDA-ARS?s Scientific Manuscript database

    Hydrogen sulfide (H2S) and nonmethane hydrocarbon (NMHC) emissions from two mechanically ventilated commercial broiler houses located in the Southeastern United States were continuously monitored over 12 flocks during the one-year period of 2006-2007 as a joint effort between Iowa State University a...

  17. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR HYDROGEN SULFIDE (EXTERNAL REVIEW DRAFT)

    EPA Science Inventory

    Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals. Occupational exposure occurs primarily from its presence in petroleum, n...

  18. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR HYDROGEN SULFIDE (EXTERNAL REVIEW DRAFT)

    EPA Science Inventory

    Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals. Occupational exposure occurs primarily from its presence in petroleum, n...

  19. CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF PRODUCTS FROM THE REACTION OF DIMETHYLARSINIC ACID WITH HYDROGEN SULFIDE

    EPA Science Inventory

    The reaction of dimethylarsinic acid (DMAV) with hydrogen sulfide (H2S) is of biological significance and may be implicated in the overall toxicity and carcinogenicity of arsenic. The course of the reaction in aqueous phase was monitored and an initial product, dimethylthioarsin...

  20. Detrimental effects for colonocytes of an increased exposure to luminal hydrogen sulfide: The adaptive response.

    PubMed

    Beaumont, Martin; Andriamihaja, Mireille; Lan, Annaïg; Khodorova, Nadezda; Audebert, Marc; Blouin, Jean-Marc; Grauso, Marta; Lancha, Luciana; Benetti, Pierre-Henri; Benamouzig, Robert; Tomé, Daniel; Bouillaud, Frédéric; Davila, Anne-Marie; Blachier, François

    2016-04-01

    Protein fermentation by the gut microbiota releases in the large intestine lumen various amino-acid derived metabolites. Among them, hydrogen sulfide (H2S) in excess has been suspected to be detrimental for colonic epithelium energy metabolism and DNA integrity. The first objective of this study was to evaluate in rats the epithelial response to an increased exposure to H2S. Experiments from colonocyte incubation and intra-colonic instillation indicate that low millimolar concentrations of the sulfide donor NaHS reversibly inhibited colonocyte mitochondrial oxygen consumption and increased gene expression of hypoxia inducible factor 1α (Hif-1α) together with inflammation-related genes namely inducible nitric oxide synthase (iNos) and interleukin-6 (Il-6). Additionally, rat colonocyte H2S detoxification capacity was severely impaired in the presence of nitric oxide. Based on the γH2AX ICW technique, NaHS did not induce DNA damage in colonocytes. Since H2S is notably produced by the gut microbiota from sulfur containing amino acids, the second objective of the study was to investigate the effects of a high protein diet (HPD) on large intestine luminal sulfide content and on the expression of genes involved in H2S detoxification in colonocytes. We found that HPD markedly increased H2S content in the large intestine but the concomitant increase of the content mass maintained the luminal sulfide concentration. HPD also provoked an increase of sulfide quinone reductase (Sqr) gene expression in colonocytes, indicating an adaptive response to increased H2S bacterial production. In conclusion, low millimolar NaHS concentration severely affects colonocyte respiration in association with increased expression of genes associated with intestinal inflammation. Although HPD increases the sulfide content of the large intestine, the colonic adaptive responses to this modification limit the epithelial exposure to this deleterious bacterial metabolite.

  1. Delivery of Hydrogen Sulfide by Ultrasound Targeted Microbubble Destruction Attenuates Myocardial Ischemia-reperfusion Injury.

    PubMed

    Chen, Gangbin; Yang, Li; Zhong, Lintao; Kutty, Shelby; Wang, Yuegang; Cui, Kai; Xiu, Jiancheng; Cao, Shiping; Huang, Qiaobing; Liao, Wangjun; Liao, Yulin; Wu, Juefei; Zhang, Wenzhu; Bin, Jianping

    2016-07-29

    Hydrogen sulfide (H2S) is an attractive agent for myocardial ischemia-reperfusion injury, however, systemic delivery of H2S may cause unwanted side effects. Ultrasound targeted microbubble destruction has become a promising tool for organ specific delivery of bioactive substance. We hypothesized that delivery of H2S by ultrasound targeted microbubble destruction attenuates myocardial ischemia-reperfusion injury and could avoid unwanted side effects. We prepared microbubbles carrying hydrogen sulfide (hs-MB) with different H2S/C3F8 ratios (4/0, 3/1, 2/2, 1/3, 0/4) and determined the optimal ratio. Release of H2S triggered by ultrasound was investigated. The cardioprotective effect of ultrasound targeted hs-MB destruction was investigated in a rodent model of myocardial ischemia-reperfusion injury. The H2S/C3F8 ratio of 2/2 was found to be an optimal ratio to prepare stable hs-MB with higher H2S loading capability. Ultrasound targeted hs-MB destruction triggered H2S release and increased the concentration of H2S in the myocardium and lung. Ultrasound targeted hs-MB destruction limited myocardial infarct size, preserved left ventricular function and had no influence on haemodynamics and respiratory. This cardioprotective effect was associated with alleviation of apoptosis and oxidative stress. Delivery of H2S to the myocardium by ultrasound targeted hs-MB destruction attenuates myocardial ischemia-reperfusion injury and may avoid unwanted side effects.

  2. Delivery of Hydrogen Sulfide by Ultrasound Targeted Microbubble Destruction Attenuates Myocardial Ischemia-reperfusion Injury

    PubMed Central

    Chen, Gangbin; Yang, Li; Zhong, Lintao; Kutty, Shelby; Wang, Yuegang; Cui, Kai; Xiu, Jiancheng; Cao, Shiping; Huang, Qiaobing; Liao, Wangjun; Liao, Yulin; Wu, Juefei; Zhang, Wenzhu; Bin, Jianping

    2016-01-01

    Hydrogen sulfide (H2S) is an attractive agent for myocardial ischemia-reperfusion injury, however, systemic delivery of H2S may cause unwanted side effects. Ultrasound targeted microbubble destruction has become a promising tool for organ specific delivery of bioactive substance. We hypothesized that delivery of H2S by ultrasound targeted microbubble destruction attenuates myocardial ischemia-reperfusion injury and could avoid unwanted side effects. We prepared microbubbles carrying hydrogen sulfide (hs-MB) with different H2S/C3F8 ratios (4/0, 3/1, 2/2, 1/3, 0/4) and determined the optimal ratio. Release of H2S triggered by ultrasound was investigated. The cardioprotective effect of ultrasound targeted hs-MB destruction was investigated in a rodent model of myocardial ischemia-reperfusion injury. The H2S/C3F8 ratio of 2/2 was found to be an optimal ratio to prepare stable hs-MB with higher H2S loading capability. Ultrasound targeted hs-MB destruction triggered H2S release and increased the concentration of H2S in the myocardium and lung. Ultrasound targeted hs-MB destruction limited myocardial infarct size, preserved left ventricular function and had no influence on haemodynamics and respiratory. This cardioprotective effect was associated with alleviation of apoptosis and oxidative stress. Delivery of H2S to the myocardium by ultrasound targeted hs-MB destruction attenuates myocardial ischemia-reperfusion injury and may avoid unwanted side effects. PMID:27469291

  3. Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study

    PubMed Central

    Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

    2014-01-01

    Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

  4. Hydrogen sulfide protects from colitis and restores intestinal microbiota biofilm and mucus production.

    PubMed

    Motta, Jean-Paul; Flannigan, Kyle L; Agbor, Terence A; Beatty, Jennifer K; Blackler, Rory W; Workentine, Matthew L; Da Silva, Gabriela J; Wang, Rui; Buret, Andre G; Wallace, John L

    2015-05-01

    Microbiota dysbiosis and impaired barrier function are among the most prominent features of inflammatory bowel disease. In the gastrointestinal tract, hydrogen sulfide (H(2)S) is an important regulator of mucosal homeostasis. We hypothesized that H(2)S promotes resolution of colonic inflammation through actions on microbiota biofilm and the mucus barrier. We used mice genetically deficient for a key enzyme for H(2)S production (cystathionine γ-lyase) and pharmacologically inhibited that enzyme during colitis in wild-type mice. We tested the effects of administering an H(2)S donor (diallyl disulfide) to rodents during hapten-induced colitis. Colonic microbiota biofilm was visualized by fluorescent in situ hybridization, and mucus granules were quantified with periodic acid-alcian blue staining. We exposed human microbiota biofilms and planktonic bacteria to H(2)S donors ex vivo to determine changes in their growth, viability, and biomass. Intestinal microbiota formed linear biofilms in the colon of healthy rodents. During colitis, microbiota biofilms were fragmented and mucus granule production decreased. Endogenous production of H(2)S had beneficial effects on establishment of microbiota biofilms and colonic mucus production. Therapeutic delivery of H(2)S into the colon reduced inflammation, restored the microbiota biofilm, and increased the production of mucus granules. In ex vivo human microbiota, H(2)S not only promoted biofilm formation but also reduced growth of planktonic bacteria. Our results suggest that H(2)S donors could be used therapeutically during colitis, facilitating correction of microbiota biofilm dysbiosis and mucus layer reconstitution.

  5. An iminocoumarin benzothiazole-based fluorescent probe for imaging hydrogen sulfide in living cells.

    PubMed

    Zhang, Huatang; Xie, Yusheng; Wang, Ping; Chen, Ganchao; Liu, Ruochuan; Lam, Yun-Wah; Hu, Yi; Zhu, Qing; Sun, Hongyan

    2015-04-01

    Hydrogen sulfide (H2S) has recently been identified as the third gaseous signaling molecule that is involved in regulating many important cellular processes. We report herein a novel fluorescent probe for detecting H2S based on iminocoumarin benzothiazole scaffold. The probe displayed high sensitivity and around 80-fold increment in fluorescence signal after reacting with H2S under physiological condition. The fluorescent intensity of the probe was linearly related to H2S concentration in the range of 0-100 μM with a detection limit of 0.15 μM (3σ/slope). The probe also showed excellent selectivity towards H2S over other biologically relevant species, including ROS, RSS and RNS. Its selectivity for H2S is 32 folds higher than other reactive sulfur species. Furthermore, the probe has been applied for imaging H2S in living cells. Cell imaging experiments demonstrated that the probe is cell-permeable and can be used to monitor the alteration of H2S concentrations in living cells. We envisage that this probe can provide useful tools to further elucidate the biological roles of H2S.

  6. Hydrogen-sulfide-mediated vasodilatory effect of nucleoside 5'-monophosphorothioates in perivascular adipose tissue.

    PubMed

    Bełtowski, Jerzy; Guranowski, Andrzej; Jamroz-Wiśniewska, Anna; Wolski, Andrzej; Hałas, Krzysztof

    2015-07-01

    Hydrogen sulfide (H2S) is synthesized in perivascular adipose tissue (PVAT) and induces vasorelaxation. We examined whether the sulfur-containing AMP and GMP analogs AMPS and GMPS can serve as the H2S donors in PVAT. H2S production by isolated rat periaortic adipose tissue (PAT) was measured with a polarographic sensor. In addition, phenylephrine-induced contractility of aortic rings with (+) or without (-) PAT was examined. Isolated PAT produced H2S from AMPS or GMPS in the presence of the P2X7 receptor agonist BzATP. Phenylephrine-induced contractility of PAT(+) rings was lower than of PAT(-) rings. AMPS or GMPS had no effect on the contractility of PAT(-) rings, but used together with BzATP reduced the contractility of PAT(+) rings when endogenous H2S production was inhibited with propargylglycine. A high-fat diet reduced endogenous H2S production by PAT. Interestingly, AMPS and GMPS were converted to H2S by PAT of obese rats, and reduced contractility of PAT(+) aortic rings isolated from these animals even in the absence of BzATP. We conclude that (i) AMPS and GMPS can be hydrolyzed to H2S by PAT when P2X7 receptors are activated, (ii) a high-fat diet impairs endogenous H2S production by PAT, (iii) AMPS and GMPS restore the anticontractile effects of PAT in obese animals without P2X7 stimulation.

  7. Emergence of Hydrogen Sulfide as an Endogenous Gaseous Signaling Molecule in Cardiovascular Disease

    PubMed Central

    Polhemus, David J.; Lefer, David J.

    2014-01-01

    Long recognized as a malodorous and highly toxic gas, recent experimental studies have revealed that hydrogen sulfide (H2S) is produced enzymatically in all mammalian species including man and exerts a number of critical actions to promote cardiovascular homeostasis and health. During the past 15 years, scientists have determined that H2S is produced by three endogenous enzymes and exerts powerful effects on endothelial cells, smooth muscle cells, inflammatory cells, mitochondria, endoplasmic reticulum, and nuclear transcription factors. These effects have been reported in multiple organ systems and the vast majority of data clearly indicate that H2S produced by the endogenous enzymes exerts cytoprotective actions. Recent preclinical studies investigating cardiovascular diseases have demonstrated that the administration of physiological or pharmacological levels of H2S attenuates myocardial injury, protects blood vessels, limits inflammation, and regulates blood pressure. H2S has emerged as a critical cardiovascular signaling molecule similar to nitric oxide (NO) and carbon monoxide (CO) with a profound impact on the heart and circulation (Figure 1). Our improved understanding of how H2S elicits protective actions, coupled with the very rapid development of novel H2S releasing agents, has resulted in heightened enthusiasm for the clinical translation of this ephemeral gaseous molecule. This review will examine our current state of knowledge regarding the actions of H2S within the cardiovascular system with an emphasis on the therapeutic potential and molecular crosstalk between H2S, NO, and CO. PMID:24526678

  8. Hydrogen sulfide post-conditioning preserves interfibrillar mitochondria of rat heart during ischemia reperfusion injury.

    PubMed

    Banu, Shakila A; Ravindran, Sriram; Kurian, Gino A

    2016-07-01

    Cardiac mitochondrial dysfunction is considered to be the main manifestation in the pathology of ischemia reperfusion injury, and by restoring its functional activity, hydrogen sulfide (H2S), a novel endogenous gaseotransmitter renders cardioprotection. Given that interfibrillar (IFM) and subsarcolemmal (SSM) mitochondria are the two main types in the heart, the present study investigates the specific H2S-mediated action on IFM and SSM during ischemic reperfusion in the Langendorff rat heart model. Rats were randomly divided into five groups, namely normal, ischemic control, reperfusion control (I/R), ischemic post-conditioning (POC), and H2S post-conditioning (POC_H2S). In reperfusion control, cardiac contractility decreased, and lactate dehydrogenase, creatine kinase, and infracted size increased compared to both normal and ischemic group. In hearts post-conditioned with H2S and the classical method improved cardiac mechanical function and decreased cardiac markers in the perfusate and infarct size significantly. Both POC and POC_H2S exerts its cardioprotective effect of preserving the IFM, as evident by significant improvement in electron transport chain enzyme activities and mitochondrial respiration. The in vitro action of H2S on IFM and SSM from normal and I/R rat heart supports H2S and mediates cardioprotection via IFM preservation. Our study indicates that IFM play an important role in POC_H2S mediated cardioprotection from reperfusion injury.

  9. The role of hydrogen sulfide in pathologies of the vital organs and its clinical application.

    PubMed

    Jin, Z; Chan, H; Ning, J; Lu, K; Ma, D

    2015-04-01

    Hydrogen sulfide (H(2)S) is one of the more recently recognised gaseous transmitters that have been shown to be involved in a large range of cellular functions. While H(2)S generally has pro-survival and anti-apoptotic effects, at higher concentrations, this effect is reversed and it becomes anti-proliferative and pro-apoptotic instead. H(2)S is also involved in a number of organ specific functions such as thermoregulation, modulating myocardial activity and broncho-dilation. H(2)S has organ protective effects in ischaemia, acting as a vasodilator and negative inotrope to reduce blood pressure. H(2)S generally has a protective effect in acute inflammation and oxidative stress from causes such as allergy and toxins. In chronic organ pathology, low H(2)S levels have been observed in a number of different diseases, while there is evidence that H(2)S may be beneficial in a number of chronic organ degenerations. A number of studies on human tissue and cell line conducted in the recent years shows H(2)S exerting largely similar effects in humans as those in animals. This may indicate that the pharmacological potential of H(2)S modulators could have therapeutic value in a large range of acute conditions such as ischaemia, toxin exposure as well as chronic conditions such as hypertension, lung diseases and neurodegenerative disease.

  10. Hydrogen sulfide at high pressure: change in stoichiometry

    NASA Astrophysics Data System (ADS)

    Goncharov, Alexander; Lobanov, Sergey; Kruglov, Ivan; Zhao, Xiao-Miao; Chen, Xiao-Jia; Oganov, Artem; Konopkova, Zuzana; Prakapenka, Vitali

    Hydrogen sulfide (H2S) was studied by x-ray synchrotron diffraction (XRD) and Raman spectroscopy up to 144 GPa at 180-295 K. We find that H2S compound become unstable with respect to formation of new compounds with different composition including pure S, H3S and HS2 depending on the thermodynamic P-T path. These results are supported by our quantum-mechanical variable-composition evolutionary simulations that show the stability of the above mentioned compounds at elevated pressures. The stability of H3S at high pressures, which we find a strong experimental and theoretical confirmation here, suggests that it is this material which is responsible for high-temperature superconducting properties reported previously. We thank DARPA, NSF, ISSP (Hefei, China), Government of Russian Federation, and Foreign Talents Introduction and Academic Exchange Program. Use of the Advanced Photon Source was supported by the U. S. Department of Energy Office of Science.

  11. Hydrogen sulfide poisoning: an antidotal role for sodium nitrite?

    PubMed

    Hall, A H; Rumack, B H

    1997-06-01

    In 2 separate incidents, 6 patients were poisoned with hydrogen sulfide (H2S) in sewer gas. In the first incident, mixing acid- and sodium hydroxide-based drain cleaners in a confined space resulted in 4 poisonings and 2 deaths. Three would-be rescuers were seriously poisoned and 1 died. Two survivors had neurological sequelae. Sodium nitrite appeared to have some clinical efficacy in 1 case. The second incident involved 2 patients working on a pump in a sewage pond. A patient lying on a raft close to the pond surface was seriously poisoned; sodium nitrite was clinically efficacious and this patient survived without developing neurological sequelae. Sodium nitrite deserves further clinical study as a potential H2S antidote.

  12. Hydrogen sulfide at high pressure: Change in stoichiometry

    NASA Astrophysics Data System (ADS)

    Goncharov, Alexander F.; Lobanov, Sergey S.; Kruglov, Ivan; Zhao, Xiao-Miao; Chen, Xiao-Jia; Oganov, Artem R.; Konôpková, Zuzana; Prakapenka, Vitali B.

    2016-05-01

    Hydrogen sulfide (H2S ) was studied by x-ray synchrotron diffraction and Raman spectroscopy up to 150 GPa at 180-295 K and by quantum-mechanical variable-composition evolutionary simulations. The experiments show that H2S becomes unstable with respect to formation of compounds with different structure and composition, including Cccm and a body-centered cubic like (R 3 m or I m -3 m ) H3S , the latter one predicted previously to show a record-high superconducting transition temperature, a Tc of 203 K. These experiments provide experimental ground for understanding of this record-high Tc. The experimental results are supported by theoretical structure searches that suggest the stability of H3S , H4S3 , H5S8 , H3S5 , and H S2 compounds that have not been reported previously at elevated pressures.

  13. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 1: Copper-Catalyzed Oxidation.

    PubMed

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors as a result of hydrogen sulfide (H2S) and low-molecular-weight thiols are commonly encountered in wine production. These odors are usually removed by the process of Cu(II) fining, a process that remains poorly understood. The present study aims to elucidate the underlying mechanisms by which Cu(II) interacts with H2S and thiol compounds (RSH) under wine-like conditions. Copper complex formation was monitored along with H2S, thiol, oxygen, and acetaldehyde concentrations after the addition of Cu(II) (50 or 100 μM) to air-saturated model wine solutions containing H2S, cysteine, 6-sulfanylhexan-1-ol, or 3-sulfanylhexan-1-ol (300 μM each). The presence of H2S and thiols in excess to Cu(II) led to the rapid formation of ∼1.4:1 H2S/Cu and ∼2:1 thiol/Cu complexes, resulting in the oxidation of H2S and thiols and reduction of Cu(II) to Cu(I), which reacted with oxygen. H2S was observed to initially oxidize rather than form insoluble copper sulfide. The proposed reaction mechanisms provide insight into the extent to which H2S can be selectively removed in the presence of thiols in wine.

  14. In site bioimaging of hydrogen sulfide uncovers its pivotal role in regulating nitric oxide-induced lateral root formation.

    PubMed

    Li, Yan-Jun; Chen, Jian; Xian, Ming; Zhou, Li-Gang; Han, Fengxiang X; Gan, Li-Jun; Shi, Zhi-Qi

    2014-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in mammals. Despite physiological changes induced by exogenous H2S donor NaHS to plants, whether and how H2S works as a true cellular signal in plants need to be examined. A self-developed specific fluorescent probe (WSP-1) was applied to track endogenous H2S in tomato (Solanum lycopersicum) roots in site. Bioimaging combined with pharmacological and biochemical approaches were used to investigate the cross-talk among H2S, nitric oxide (NO), and Ca(2+) in regulating lateral root formation. Endogenous H2S accumulation was clearly associated with primordium initiation and lateral root emergence. NO donor SNP stimulated the generation of endogenous H2S and the expression of the gene coding for the enzyme responsible for endogenous H2S synthesis. Scavenging H2S or inhibiting H2S synthesis partially blocked SNP-induced lateral root formation and the expression of lateral root-related genes. The stimulatory effect of SNP on Ca(2+) accumulation and CaM1 (calmodulin 1) expression could be abolished by inhibiting H2S synthesis. Ca(2+) chelator or Ca(2+) channel blocker attenuated NaHS-induced lateral root formation. Our study confirmed the role of H2S as a cellular signal in plants being a mediator between NO and Ca(2+) in regulating lateral root formation.

  15. New nitric oxide or hydrogen sulfide releasing aspirins.

    PubMed

    Lazzarato, Loretta; Chegaev, Konstantin; Marini, Elisabetta; Rolando, Barbara; Borretto, Emily; Guglielmo, Stefano; Joseph, Sony; Di Stilo, Antonella; Fruttero, Roberta; Gasco, Alberto

    2011-08-11

    A new series of (((R-oxy)carbonyl)oxy)methyl esters of aspirin (ASA), bearing nitric oxide (NO) or hydrogen sulfide (H(2)S) releasing groups, was synthesized, and the compounds were evaluated as new ASA co-drugs. All the products were quite stable in buffered solution at pH 1 and 7.4. Conversely, they were all rapidly metabolized, producing ASA and the NO/H(2)S releasing moiety used for their preparation. Consequent on ASA release, the compounds were capable of inhibiting collagen-induced platelet aggregation of human platelet-rich plasma (PRP). The simple NO/H(2)S donor substructures were able to relax contracted rat aorta strips, with a NO- and H(2)S-dependent mechanism, respectively, but they either did not trigger antiaggregatory activity or displayed antiplatelet potency markedly below that of the related co-drug. The new products might provide a safer and improved alternative to the use of ASA principally in its anti-inflammatory and antithrombotic applications.

  16. Acute pit gas (hydrogen sulfide) poisoning in confinement cattle.

    PubMed

    Hooser, S B; Van Alstine, W; Kiupel, M; Sojka, J

    2000-05-01

    Rapid deaths in confinement cattle caused by exposure to hydrogen sulfide (H2S) gas from manure pits has not been reported in the USA. In 1997, 158 cattle in 2 confinement pens were exposed to H2S gas as the manure in the pits under a slatted floor was agitated prior to pumping. Approximately 35 of the cattle were lying on the floor when the upper agitator was turned on. Within 5 minutes, many these cattle were down on their sides and paddling. Of these, 26 died within a few minutes. The survivors were treated and sent to slaughter. Cattle that did not show immediate signs of toxicosis remained clinically unaffected. Two steers that were near death were brought to the Purdue Animal Disease Diagnostic Laboratory for clinical evaluation, euthanasia, and necropsy. They were recumbent and unresponsive to visual and auditory stimuli. Necropsy examination yielded no significant gross lesions. No evidence of viral or bacterial infection was found. Ocular fluid nitrate concentrations were within normal limits, and no lead was detected in either animal. Microscopic examination revealed lesions consistent with H2S-induced central nervous system anoxia. Histologically, sections of brain demonstrated massive, diffuse cerebral cortical laminar necrosis and edema. Portions of the outer lamina contained hypereosinophilic and shrunken neurons. The subcortical white matter was vacuolated in some areas. The history, clinical signs, and histologic lesion of cerebral laminar necrosis led to a diagnosis of H2S toxicosis in these cattle.

  17. Interactions between oxygen homeostasis, food availability, and hydrogen sulfide signaling

    PubMed Central

    Iranon, Nicole N.; Miller, Dana L.

    2012-01-01

    The ability to sense and respond to stressful conditions is essential to maintain organismal homeostasis. It has long been recognized that stress response factors that improve survival in changing conditions can also influence longevity. In this review, we discuss different strategies used by animals in response to decreased O2 (hypoxia) to maintain O2 homeostasis, and consider interactions between hypoxia responses, nutritional status, and H2S signaling. O2 is an essential environmental nutrient for almost all metazoans as it plays a fundamental role in development and cellular metabolism. However, the physiological response(s) to hypoxia depend greatly on the amount of O2 available. Animals must sense declining O2 availability to coordinate fundamental metabolic and signaling pathways. It is not surprising that factors involved in the response to hypoxia are also involved in responding to other key environmental signals, particularly food availability. Recent studies in mammals have also shown that the small gaseous signaling molecule hydrogen sulfide (H2S) protects against cellular damage and death in hypoxia. These results suggest that H2S signaling also integrates with hypoxia response(s). Many of the signaling pathways that mediate the effects of hypoxia, food deprivation, and H2S signaling have also been implicated in the control of lifespan. Understanding how these pathways are coordinated therefore has the potential to reveal new cellular and organismal homeostatic mechanisms that contribute to longevity assurance in animals. PMID:23233860

  18. Hydrogen sulfide and cerebral microvascular tone in newborn pigs

    PubMed Central

    Parfenova, Helena; Basuroy, Shyamali; Jaggar, Jonathan H.; Umstot, Edward S.; Fedinec, Alexander L.

    2011-01-01

    Hydrogen sulfide (H2S) is a gaseous signaling molecule that appears to be involved in numerous biological processes, including regulation of blood pressure and vascular tone. The present study is designed to address the hypothesis that H2S is a functionally significant, endogenous dilator in the newborn cerebrovascular circulation. In vivo experiments were conducted using newborn pigs with surgically implanted, closed, cranial windows. Topical application of H2S concentration-dependently (10−6 to 2 × 10−4 M) dilated pial arterioles. This dilation was blocked by glibenclamide (10−6 M). l-Cysteine, the substrate of the H2S-producing enzymes cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS), also dilated pial arterioles. The dilation to l-cysteine was blocked by the CSE inhibitor d,l-propargylglycine (PPG, 10 mM) but was unaffected by the CBS inhibitor amino-oxyacetate (AOA, 1 mM). Western blots detected CSE, but not CBS, in cerebral microvessels, whereas CBS is detected in brain parenchyma. Immunohistological CSE expression is predominantly vascular while CBS is expressed mainly in neurons and astrocytes. l-Cysteine (5 mM) increased H2S concentration in cerebrospinal fluid (CSF), measured by GC-MS, from 561 ± 205 to 2,783 ± 818 nM before but not during treatment with PPG (1,030 ± 70 to 622 ± 78 nM). Dilation to hypercapnia was inhibited by PPG but not AOA. Hypercapnia increased CSF H2S concentration from 763 ± 243 to 4,337 ± 1789 nM before but not during PPG treatment (357 ± 178 vs. 425 ± 217 nM). These data show that H2S is a dilator of the newborn cerebral circulation and that endogenous CSE can produce sufficient H2S to decrease vascular tone. H2S appears to be a physiologically significant dilator in the cerebral circulation. PMID:21131483

  19. In-situ preparation of N-TiO2/graphene nanocomposite and its enhanced photocatalytic hydrogen production by H2S splitting under solar light.

    PubMed

    Bhirud, Ashwini P; Sathaye, Shivaram D; Waichal, Rupali P; Ambekar, Jalindar D; Park, Chan-J; Kale, Bharat B

    2015-03-21

    Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. ∼5941 μmol h(-1) under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to 'N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst.

  20. The role of hydrogen sulfide in aging and age-related pathologies

    PubMed Central

    Perridon, Bernard W.; Leuvenink, Henri G.D.; Hillebrands, Jan-Luuk; van Goor, Harry; Bos, Eelke M.

    2016-01-01

    When humans grow older, they experience inevitable and progressive loss of physiological function, ultimately leading to death. Research on aging largely focuses on the identification of mechanisms involved in the aging process. Several proposed aging theories were recently combined as the ‘hallmarks of aging’. These hallmarks describe (patho-)physiological processes that together, when disrupted, determine the aging phenotype. Sustaining evidence shows a potential role for hydrogen sulfide (H2S) in the regulation of aging. Nowadays, H2S is acknowledged as an endogenously produced signaling molecule with various (patho-) physiological effects. H2S is involved in several diseases including pathologies related to aging. In this review, the known, assumed and hypothetical effects of hydrogen sulfide on the aging process will be discussed by reviewing its actions on the hallmarks of aging and on several age-related pathologies. PMID:27683311

  1. Force-Induced H2S by PDLSCs Modifies Osteoclastic Activity during Tooth Movement.

    PubMed

    Liu, F; Wen, F; He, D; Liu, D; Yang, R; Wang, X; Yan, Y; Liu, Y; Kou, X; Zhou, Y

    2017-02-01

    Hydrogen sulfide (H2S), a gasotransmitter, has been recently linked to mesenchymal stem cell (MSC) function and bone homeostasis. Periodontal ligament stem cells (PDLSCs) are the main MSCs in PDL, which respond to mechanical force to induce physiological activities during orthodontic tooth movement (OTM). However, it is unknown whether mechanical force might induce endogenous H2S production by PDLSCs to regulate alveolar bone homeostasis. Here, we used a mouse OTM model to demonstrate that orthodontic force-induced endogenous H2S production in PDL tissue was associated with macrophage accumulation and osteoclastic activity in alveolar bone. Then, we showed that mechanical force application induced cystathionine β-synthase (CBS) expression and endogenous H2S production by PDLSCs. Moreover, blocking endogenous H2S or systemically increasing H2S levels could decrease or enhance force-induced osteoclastic activities to control tooth movement. We further revealed how force-induced H2S production by PDLSCs contributed to the secretion of monocyte chemoattractant protein-1 (MCP-1) and the expression of receptor activator of nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) system by PDLSCs. The secretion and expression of these factors controlled macrophage migration and osteoclast differentiation. This study demonstrated that PDLSCs produced H2S to respond to and transduce force signals. Force-induced gasotransmitter H2S production in PDLSCs therefore regulated osteoclastic activities in alveolar bone and controlled the OTM process through the MCP-1 secretion and RANKL/OPG system.

  2. Protective Actions of H2S in Acute Myocardial Infarction and Heart Failure.

    PubMed

    Donnarumma, Erminia; Trivedi, Rishi K; Lefer, David J

    2017-03-16

    Hydrogen sulfide (H2S) was identified as the third gasotransmitter in 1996 following the discoveries of the biological importance of nitric oxide and carbon monoxide. Although H2S has long been considered a highly toxic gas, the discovery of its presence and enzymatic production in mammalian tissues supports a critical role for this physiological signaling molecule. H2S is synthesized endogenously by three enzymes: cystathionine β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase. H2S plays a pivotal role in the regulation of cardiovascular function as H2S has been shown to modulate: vasodilation, angiogenesis, inflammation, oxidative stress, and apoptosis. Perturbation of endogenous production of H2S has been associated with many pathological conditions of the cardiovascular system such as diabetes, heart failure, and hypertension. As such, modulation of the endogenous H2S signaling pathway or administration of exogenous H2S has been shown to be cytoprotective. This review article will provide a summary of the current body of evidence on the role of H2S signaling in the setting of myocardial ischemia and heart failure. © 2017 American Physiological Society. Compr Physiol 7:583-602, 2017. Copyright © 2017 John Wiley & Sons, Inc.

  3. H2S confers colonoprotection against TNBS-induced colitis by HO-1 upregulation in rats.

    PubMed

    Kupai, Krisztina; Almási, Nikoletta; Kósa, Magdolna; Nemcsók, János; Murlasits, Zsolt; Török, Szilvia; Al-Awar, Amin; Baráth, Zoltán; Pósa, Anikó; Varga, Csaba

    2017-08-02

    Hydrogen sulfide (H2S) is an endogenous mediator that contributes to many important physiological processes including vasodilation and vascular smooth muscle relaxation; in turn, preventing tissue damage and reducing inflammation. Heme oxygenase (HO) enzymes, of which HO-1 is inducible by harmful stimuli, were found to regulate intestinal inflammation in experimental animal models of colitis. We aimed to investigate the protective effects of H2S against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats, and whether HO enzyme system is involved in the H2S-induced colonic cytoprotection. Male Wistar rats were treated with TNBS to induce colitis, and H2S donor (Lawesson's reagent) was prepared two times/day at different concentrations, and delivered per os (from day 1 to day 3). Our results suggest that daily treatment (2 times/day) with H2S donor, could significantly decrease the extent of colonic inflammation compared to vehicle treatment, and the most effective daily dose of H2S donor against inflammation was 18.75 µM/kg/day. Per os administration of H2S donor increased the colonic HO enzyme activity; on the contrary, the protective effect of H2S was abolished by the co-treatment with HO inhibitor. Our findings suggest that H2S confers colonoprotection, probably by modulation of anti-inflammatory parameters and HO enzyme activity.

  4. Reactions of isolated persulfides provide insights into the interplay between H2S and persulfide reactivity.

    PubMed

    Bailey, T Spencer; Pluth, Michael D

    2015-12-01

    Hydrogen sulfide is ubiquitous in biological systems and exerts function over a wide range of important physiological processes. Complementing free H2S, the reductant-labile sulfur pool plays significant roles in the translocation and action of sulfide, however the chemistry of reductant-labile sulfide sources has not been studied systematically. Using a combination of NMR and UV-Vis spectroscopy, we investigated the spectroscopic properties and reactivity of three isolated organic persulfides and report a simple model for persulfide reactivity, including their roles as nucleophiles, electrophiles, and sulfide donors. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Mechanisms of hydrogen sulfide removal by ground granulated blast furnace slag amended soil.

    PubMed

    Xie, Mengyao; Leung, Anthony Kwan; Ng, Charles Wang Wai

    2017-05-01

    Ground granulated blast furnace slag (GGBS) amended soil has been found able to remove gaseous hydrogen sulfide (H2S). However, how H2S is removed by GGBS amended soil and why GGBS amended soil can be regenerated to remove H2S are not fully understood. In this study, laboratory column tests together with chemical analysis were conducted to investigate and reveal the mechanisms of H2S removal process in GGBS amended soil. Sulfur products formed on the surface of soil particle and in pore water were quantified. The test results reveal that the reaction between H2S and GGBS amended soil was a combined process of oxidation and acid-base reaction. The principal mechanism to remove H2S in GGBS amended soil was through the formation of acid volatile sulfide (AVS), elemental sulfur and thiosulfate. Soil pH value decreased gradually during regeneration and reuse cycles. It is found that the AVS plays a significant role in H2S removal during regeneration and reuse cycles. Adding GGBS increased the production of AVS and at the same time suppressed the formation of elemental sulfur. This mechanism is found to be more prominent when the soil water content is higher, leading to increased removal capacity.

  6. The yeast TUM1 affects production of hydrogen sulfide from cysteine treatment during fermentation.

    PubMed

    Huang, Chien-Wei; Walker, Michelle E; Fedrizzi, Bruno; Roncoroni, Miguel; Gardner, Richard C; Jiranek, Vladimir

    2016-12-01

    The undesirable rotten-egg odour of hydrogen sulfide (H2S) produced by yeast shortly after yeast inoculation of grape musts might be an important source of desirable varietal thiols, which contribute to tropical aromas in varieties such as Sauvign-on Blanc. In this study, we observed that Saccharomyces cerevisiae strains produce an early burst of H2S from cysteine. Both Δmet2 and Δmet17 strains produce a larger burst, likely because they are unable to utilise the H2S in the sulfate assimilation pathway. For the first time, we show that TUM1 is partly responsible for the early production of H2S from cysteine. Overex-pressing TUM1 elevated production of H2S, whilst its deletion yields only half of the H2S. We further confirmed that yeast convert cysteine to H2S by analysing growth of mutants lacking components of the transsulfuration pathway. High concent-rations of cysteine overcame this growth block, but required TUM1 Collectively, the data indicate that S. cerevisiae does not convert cysteine to sulfate or sulfite, but rather to sulfide via a novel pathway that requires the action of Tum1p. The findi-ngs of this study may allow the improvement of commercial yeasts through the manipulation of sulfur metabolism that are better suited towards production of fruit-driven styles. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Impacts of meteorological factors on hydrogen sulfide concentration downwind of geothermal power plants

    NASA Astrophysics Data System (ADS)

    Olafsdottir, S.; Gardarsson, S. M.

    2013-10-01

    Hydrogen sulfide (H2S) concentration in the city of Reykjavik, downwind of geothermal power plants has been studied with respect to meteorological factors as the odor and other effects are starting to become a nuisance. The main sources of H2S in Reykjavik City were the Nesjavellir and Hellisheidi Geothermal Power Plants, which are both less than 35 km east of the city. The H2S concentration in Reykjavik was correlated with the H2S emissions from the power plants but was also heavily influenced by weather conditions. The results showed that the H2S concentration at the Grensasvegur Measuring Station was elevated when the wind direction was from 54° to 125°, especially when the wind direction was stable for several hours. The H2S concentration in Reykjavik was highest when the wind speed in the city was between 1.5 and 4 m s-1, and decreased rapidly with higher wind speeds. H2S concentration showed correlation with the air temperature in the city below 3 °C and the concentration rose as the temperature decreased, and the air became more stable and was highest when there was a temperature inversion. The quantitative effects of precipitation on H2S concentration could not be determined in this study although the events with the highest H2S concentration occurred when there was no precipitation. The results showed that favorable conditions for high H2S events can be expected in Reykjavik 2-6 times per year and events with H2S concentration exceeding 50 μg m-3 might be expected on average about 2 times per year. The results also indicate that events with high H2S concentration can be predicted by using a current weather forecast.

  8. Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle.

    PubMed

    Dombkowski, Ryan A; Doellman, Meredith M; Head, Sally K; Olson, Kenneth R

    2006-08-01

    Hydrogen sulfide (H2S) is a recently identified gasotransmitter that may mediate hypoxic responses in vascular smooth muscle. H2S also appears to be a signaling molecule in mammalian non-vascular smooth muscle, but its existence and function in non-mammalian non-vascular smooth muscle have not been examined. In the present study we examined H2S production and its physiological effects in urinary bladder from steelhead and rainbow trout (Oncorhynchus mykiss) and evaluated the relationship between H2S and hypoxia. H2S was produced by trout bladders, and its production was sensitive to inhibitors of cystathionine beta-synthase and cystathionine gamma-lyase. H2S produced a dose-dependent relaxation in unstimulated and carbachol pre-contracted bladders and inhibited spontaneous contractions. Bladders pre-contracted with 80 mmol l(-1) KCl were less sensitive to H2S than bladders contracted with either 80 mmol l(-1) KC2H3O2 (KAc) or carbachol, suggesting that some of the H2S effects are mediated through an ion channel. However, H2S relaxation of bladders was not affected by the potassium channel inhibitors, apamin, charybdotoxin, 4-aminopyridine, and glybenclamide, or by chloride channel/exchange inhibitors 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt, tamoxifen and glybenclamide, or by the presence or absence of extracellular HCO3-. Inhibitors of neuronal mechanisms, tetrodotoxin, strychnine and N-vanillylnonanamide were likewise ineffective. Hypoxia (aeration with N2) also relaxed bladders, was competitive with H2S for relaxation, and it was equally sensitive to KCl, and unaffected by neuronal blockade or the presence of extracellular HCO3-. Inhibitors of H2S synthesis also inhibited hypoxic relaxation. These experiments suggest that H2S is a phylogenetically ancient gasotransmitter in non-mammalian non-vascular smooth muscle and that it serves as an oxygen sensor/transducer, mediating the effects of hypoxia.

  9. The Redox Chemistry and Chemical Biology of H2S, Hydropersulfides and Derived Species: Implications to Their Possible Biological Activity and Utility

    PubMed Central

    Ono, Katsuhiko; Akaike, Takaake; Sawa, Tomohiro; Kumagai, Yoshito; Wink, David A.; Tantillo, Dean J.; Hobbs, Adrian J.; Nagy, Peter; Xian, Ming; Lin, Joseph; Fukuto, Jon M.

    2014-01-01

    Hydrogen sulfide (H2S) is an endogenously generated and putative signaling/effector molecule. In spite of its numerous reported functions, the chemistry by which it elicits its functions is not understood. Moreover, recent studies allude to the existence of other sulfur species besides H2S that may play critical physiological roles. Herein, the basic chemical biology of H2S as well as other related or derived species is discussed and reviewed. A particular focus of this review are the per- and poly-sulfides which are likely in equilibrium with free H2S and which may be important biological effectors themselves. PMID:25229186

  10. Metal hydrogen sulfide superconducting temperature

    NASA Astrophysics Data System (ADS)

    Kudryashov, N. A.; Kutukov, A. A.; Mazur, E. A.

    2017-01-01

    Éliashberg theory is generalized to the electronphonon (EP) systems with the not constant density of electronic states. The phonon contribution to the anomalous electron Green's function (GF) is considered. The generalized Éliashberg equations with the variable density of electronic states are resolved for the hydrogen sulphide SH3 phase under pressure. The dependence of both the real and the imaginary part of the order parameter on the frequency in the SH3 phase is obtained. The Tc = 177 K value in the hydrogen sulfide SH3 phase at the pressure P = 225 GPa has been defined. The results of the solution of the Eliashberg equations for the Im-3m (170 GPa), Im-3m (200 GPa) and R3m (120 GPa) phases are presented. A peak value Tc = 241 K of the superconducting transition temperature has been predicted.

  11. Hydrogen sulfide inhibits the calcification and osteoblastic differentiation of vascular smooth muscle cells

    PubMed Central

    Zavaczki, Erzsébet; Jeney, Viktória; Agarwal, Anupam; Zarjou, Abolfazl; Oros, Melinda; Katkó, Mónika; Varga, Zsuzsa; Balla, György; Balla, József

    2011-01-01

    Osteoblastic differentiation of vascular smooth muscle cells (VSMCs) is involved in the pathogenesis of vascular calcification. Hydrogen sulfide (H2S) is a gas endogenously produced by cystathionine γ-lyase in VSMC. Here we determined whether H2S plays a role in phosphate-induced osteoblastic transformation and mineralization of VSMC. Hydrogen sulfide was found to inhibit calcium deposition in the extracellular matrix and to suppress the induction of the genes involved in osteoblastic transformation of VSMC: alkaline phosphatase, osteocalcin, and Cbfa1. Moreover, phosphate uptake and phosphate-triggered upregulation of the sodium-dependent phosphate cotransporter (Pit-1) were also prevented by H2S. Reduction of endogenous production of H2S by inhibition of cystathionine γ-lyase activity resulted in increased osteoblastic transformation and mineralization. Low plasma levels of H2S, associated with decreased cystathionine γ-lyase enzyme activity, were found in patients with chronic kidney disease receiving hemodialysis. Thus, H2S is a potent inhibitor of phosphate-induced calcification and osteoblastic differentiation of VSMC. This mechanism might contribute to accelerated vascular calcification in chronic kidney disease. PMID:21716261

  12. Molecular and dissociative adsorption of water and hydrogen sulfide at perfect and defective Cu(110) surfaces.

    PubMed

    Lousada, Cláudio M; Johansson, Adam Johannes; Korzhavyi, Pavel A

    2017-03-15

    We performed a density functional theory (DFT) investigation of the molecular and dissociative adsorption of H2O and H2S at perfect and defective Cu(110) surfaces described using supercells with c(6 × 6) periodicity. The defective surface consists of a terrace surrounded by pits. We found considerable differences in adsorption modes and energies for H2O and H2S. At the defective Cu(110) surface, monomers of H2O and H2S preferentially adsorb at the terrace site and molecular adsorption of H2O is significantly more favorable than that of H2S. For dissociative adsorption however, the sulfur species are considerably more stable than the oxygen species. For monolayer (ML) coverages, there are small differences in the molecular adsorption energies for H2O and H2S. However, for the formation of 1 ML of HO and 1 ML of HS from 1 ML of H2O and 1 ML of H2S, respectively, with the release of H2(g), the differences are very large. The formation of 1 ML HO at the perfect Cu(110) surface is endoergic, while at the defective Cu(110) surface it is exoergic by -0.6 eV. For high coverages, H2S forms stacked half-monolayers that interact with each other via a complex hydrogen bond network with a strength per H2S molecule of -0.140 eV per H2S and -0.120 eV per H2S for H2S located in the underlayer and overlayer, respectively. The large distances between hydrogen bonded H2S molecules explain the preference for the formation of the two stacked half-monolayers of H2S instead of a single monolayer as it happens with H2O. Additionally, the formation of 1 ML of HS does not occur because of the spontaneous splitting of some H-S bonds resulting in surface bound HS and S and H2S molecules. Extensive surface reconstruction and relaxation accompanies adsorption of the sulfur adsorbates. Such reconstructions with outwards pull of Cu atoms can be at the origin of the weak adhesion of sulfide films that explains the release of CuS particles from copper sulfide films at copper surfaces. Overall, the

  13. Hydrogen recovery from hydrogen sulfide by oxidation and by decomposition

    SciTech Connect

    Yang, B.L.; Kung, H.H. . Ipatieff Lab. and Chemical Engineering Dept.)

    1994-05-01

    Selective oxidation of hydrogen sulfide to hydrogen and sulfur oxides in a two-step process and the catalytic decomposition of hydrogen sulfide were studied for the recovery of hydrogen from hydrogen sulfide. Platinum, when adequately dispersed on a silica support, was found to be effective in reacting with hydrogen sulfide to produce hydrogen and platinum sulfide at 500 C. The platinum sulfide could then be treated with oxygen at 400 C to release sulfur oxides and regenerate the platinum. However, oxidation of sulfur dioxide to trioxide, retention of oxygen by platinum, and adsorption of hydrogen sulfide by the silica support also occurred, which resulted in a minor loss in hydrogen yield. In the decomposition of hydrogen sulfide, platinum sulfide was found to be catalytically active. The equilibrium hydrogen yields were measured experimentally over the range 350--650 C and compared with the values calculated on the basis of a model that included the S, allotropes, the H[sub 2]S[sub n] sulfanes, and HS. The values agreed well at low temperatures but deviated from each other up to 20% at high temperatures.

  14. Catalyst and process for oxidizing hydrogen sulfide

    SciTech Connect

    Hass, R.H.; Ward, J.W.

    1984-04-24

    Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO/sub 2/. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO/sub 2/.

  15. Ammonia and hydrogen sulfide removal using biochar

    USDA-ARS?s Scientific Manuscript database

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  16. Impaired Hydrogen Sulfide-Mediated Vasodilation Contributes to Microvascular Endothelial Dysfunction in Hypertensive Adults.

    PubMed

    Greaney, Jody L; Kutz, Jessica L; Shank, Sean W; Jandu, Sandeep; Santhanam, Lakshmi; Alexander, Lacy M

    2017-05-01

    Reductions in hydrogen sulfide (H2S) production have been implicated in the pathogenesis of vascular dysfunction in animal models of hypertension; however, no studies have examined a functional role for H2S in contributing to microvascular dysfunction in hypertensive (HTN) adults. We hypothesized that endogenous production of H2S would be reduced, impaired endothelium-dependent vasodilation would be mediated by reductions in H2S-dependent vasodilation, and vascular responsiveness to exogenous H2S (sodium sulfide) would be attenuated in HTN compared to normotensive adults. Fifteen normotensive (51±2 years; blood pressure, 116±3/76±3 mm Hg) and 14 HTN adults (57±2 years; blood pressure 140±3/89±2 mm Hg) participated. H2S biosynthetic enzyme expression (Western blot) and substrate-dependent H2S production (amperometric probe) were measured in cutaneous tissue homogenates. Red cell flux (laser Doppler flowmetry) was measured during graded perfusions of acetylcholine (ACh; 10(-6)-10(-1) mol/L) and sodium sulfide (10(-5)-10(1) mol/L) using intradermal microdialysis; the functional role of H2S was determined using pharmacological inhibition with aminooxyacetic acid (0.5 mmol/L). H2S biosynthetic enzyme expression and substrate-dependent H2S production were reduced in HTN adults (all P<0.05). ACh-induced endothelium-dependent vasodilation was blunted in HTN adults (P=0.012). Aminooxyacetic acid attenuated ACh-induced vasodilation in normotensive adults (ACh, 1.31±0.13 versus ACh+aminooxyacetic acid, 1.07±0.09 flux/mm Hg; P=0.025) but had no effect on vasodilation in HTN adults (ACh, 1.16±0.10 versus ACh+aminooxyacetic acid, 1.37±0.11 flux/mm Hg; P=0.47). Sodium sulfide-induced vasodilation was not different between groups. Collectively, these findings indicate that while the microvasculature maintains the ability to vasodilate in response to exogenous H2S, reductions in endogenous synthesis and H2S-dependent vasodilation contribute to endothelial

  17. Controlled release hydrogen sulfide delivery system based on mesoporous silica nanoparticles protects graft endothelium from ischemia-reperfusion injury.

    PubMed

    Wang, Wenshuo; Sun, Xiaotian; Zhang, Huili; Yang, Cheng; Liu, Ye; Yang, Wuli; Guo, Changfa; Wang, Chunsheng

    2016-01-01

    Hydrogen sulfide (H2S) functions as a protective gas transmitter in various physiological and pathological processes, but the lack of ideal donors severely hampers the clinical application of H2S. This study aims to construct a controlled release H2S donor and evaluate its protective effect on graft endothelium. Mesoporous silica nanoparticles (MSNs) were synthesized using the sol-gel method and loaded with diallyl trisulfide (DATS), an H2S-releasing agent named DATS-MSN. In vitro experiments showed that DATS-MSN could alleviate endothelial cell inflammation and enhance endothelial cell proliferation and migration. In vivo experiments demonstrated that the apoptosis of graft endothelium was mitigated in the presence of DATS-MSN. Our results indicated that DATS-MSN, releasing H2S in a controlled release fashion, could serve as an ideal H2S donor.

  18. Controlled release hydrogen sulfide delivery system based on mesoporous silica nanoparticles protects graft endothelium from ischemia–reperfusion injury

    PubMed Central

    Wang, Wenshuo; Sun, Xiaotian; Zhang, Huili; Yang, Cheng; Liu, Ye; Yang, Wuli; Guo, Changfa; Wang, Chunsheng

    2016-01-01

    Hydrogen sulfide (H2S) functions as a protective gas transmitter in various physiological and pathological processes, but the lack of ideal donors severely hampers the clinical application of H2S. This study aims to construct a controlled release H2S donor and evaluate its protective effect on graft endothelium. Mesoporous silica nanoparticles (MSNs) were synthesized using the sol–gel method and loaded with diallyl trisulfide (DATS), an H2S-releasing agent named DATS-MSN. In vitro experiments showed that DATS-MSN could alleviate endothelial cell inflammation and enhance endothelial cell proliferation and migration. In vivo experiments demonstrated that the apoptosis of graft endothelium was mitigated in the presence of DATS-MSN. Our results indicated that DATS-MSN, releasing H2S in a controlled release fashion, could serve as an ideal H2S donor. PMID:27486324

  19. Dual effects of hydrogen sulfide donor on meiosis and cumulus expansion of porcine cumulus-oocyte complexes.

    PubMed

    Nevoral, Jan; Petr, Jaroslav; Gelaude, Armance; Bodart, Jean-Francois; Kucerova-Chrpova, Veronika; Sedmikova, Marketa; Krejcova, Tereza; Kolbabova, Tereza; Dvorakova, Marketa; Vyskocilova, Alena; Weingartova, Ivona; Krivohlavkova, Lenka; Zalmanova, Tereza; Jilek, Frantisek

    2014-01-01

    Hydrogen sulfide (H2S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H2S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observed that the H2S donor, Na2S, accelerated oocyte in vitro maturation in a dose-dependent manner, following an increase of MPF activity around germinal vesicle breakdown. Concurrently, the H2S donor affected cumulus expansion, monitored by hyaluronic acid production. Our results suggest that the H2S donor influences oocyte maturation and thus also participates in the regulation of cumulus expansion. The exogenous H2S donor apparently affects key signal pathways of oocyte maturation and cumulus expansion, resulting in faster oocyte maturation with little need of cumulus expansion.

  20. Hydrogen Sulfide Maintains Mesenchymal Stem Cell Function and Bone Homeostasis via Regulation of Ca2+ Channel Sulfhydration

    PubMed Central

    Liu, Yi; Yang, Ruili; Liu, Xibao; Zhou, Yu; Qu, Cunye; Kikuiri, Takashi; Wang, Songlin; Zandi, Ebrahim; Du, Junbao; Ambudkar, Indu S.; Shi, Songtao

    2014-01-01

    SUMMARY Gaseous signaling molecules such as hydrogen sulfide (H2S) are produced endogenously and mediate effects through diverse mechanisms. H2S is one such gasotrasmitter which regulates multiple signaling pathways in mammalian cells, and abnormal H2S metabolism has been linked to defects in bone homeostasis. Here, we demonstrate that bone marrow mesenchymal stem cells (BMMSCs) produce H2S to regulate their self-renewal and osteogenic differentiation, and H2S deficiency results in defects in BMMSC differentiation. H2S deficiency causes aberrant intracellular Ca2+ influx, due to reduced sulfhydration of cysteine residues on multiple Ca2+ TRP channels. This decreased Ca2+ flux downregulates PKC/Erk-mediated Wnt/β-catenin signaling which controls osteogenic differentiation of BMMSCs. Consistently, H2S-deficient mice display an osteoporotic phenotype, which can be rescued by small molecules which release H2S. These results demonstrate H2S regulates BMMSCs, and restoring H2S levels via non-toxic donors may provide treatments for diseases such as osteoporosis which can arise from H2S deficiencies. PMID:24726192

  1. Hydrogen sulfide pollution in wastewater treatment facilities

    SciTech Connect

    AlDhowalia, K.H. )

    1987-01-01

    The hydrogen sulfide (H{sub 2}S) found in wastewater collection systems and wastewater treatment facilities results from the bacterial reduction of the sulfate ion (SO{sub 4}). Hydrogen sulfide is a gas that occurs both in the sewer atmosphere and as a dissolved gas in the wastewater. When raw wastewater first enters the wastewater treatment facility by gravity most of the hydrogen sulfide is in the gaseous phase and will escape into the atmosphere at the inlet structures. Also some of the dissolved hydrogen sulfide will be released at points of turbulance such as at drops in flow, flumes, or aeration chambers. Several factors can cause excessive hydrogen sulfide concentrations in a sewerage system. These include septic sewage, long flow times in the sewerage system, high temperatures, flat sewer grades, and poor ventilation. These factors are discussed in this paper.

  2. Inhibition of hydrogen sulfide generation from disposed gypsum drywall using chemical inhibitors.

    PubMed

    Xu, Qiyong; Townsend, Timothy; Bitton, Gabriel

    2011-07-15

    Disposal of gypsum drywall in landfills has been demonstrated to elevate hydrogen sulfide (H(2)S) concentrations in landfill gas, a problem with respect to odor, worker safety, and deleterious effect on gas-to-energy systems. Since H(2)S production in landfills results from biological activity, the concept of inhibiting H(2)S production through the application of chemical agents to drywall during disposal was studied. Three possible inhibition agents - sodium molybdate (Na(2)MoO(4)), ferric chloride (FeCl(3)), and hydrated lime (Ca(OH)(2)) - were evaluated using flask and column experiments. All three agents inhibited H(2)S generation, with Na(2)MoO(4) reducing H(2)S generation by interrupting the biological sulfate reduction process and Ca(OH)(2) providing an unfavorable pH for biological growth. Although FeCl(3) was intended to provide an electron acceptor for a competing group of bacteria, the mechanism found responsible for inhibiting H(2)S production in the column experiment was a reduction in pH. Application of both Na(2)MoO(4) and FeCl(3) inhibited H(2)S generation over a long period (over 180 days), but the impact of Ca(OH)(2) decreased with time as the alkalinity it contributed was neutralized by the generated H(2)S. Practical application and potential environmental implications need additional exploration.

  3. Hydrogen sulfide toxicity inhibits primary root growth through the ROS-NO pathway.

    PubMed

    Zhang, Ping; Luo, Qiong; Wang, Ruling; Xu, Jin

    2017-04-13

    High concentrations of hydrogen sulfide (H2S) are toxic to plants and inhibit their growth. Previous research indicated that high concentrations of H2S modulate the root system architecture (RSA) by affecting auxin transport; however, the signaling pathway underlying this process remains unclear. Here, we investigated the effects of exogenous sodium hydrosulfide (NaHS), an H2S donor, on primary root (PR) growth in Arabidopsis using pharmacological, physiological, and genetic approaches. H2S toxicity repressed PR growth by triggering a signal transduction pathway involving reactive oxygen species (ROS) accumulation, MITOGEN-ACTIVATED PROTEIN KINASE 6 (MPK6) activation, and nitric oxide (NO) production. Respiratory burst oxidase homolog mutants and an NO synthase mutant were less sensitive to NaHS, suggesting that both ROS and NO mediate the inhibitory effects of H2S on PR growth. We found that exogenous H2S-activated ROS production was required for NO generation and that MPK6 mediated H2S-induced NO production. MPK6 was shown to function downstream of ROS and upstream of NO. Finally, we demonstrated that exogenous H2S repressed the distribution of auxin and reduced the meristematic cell division potential in root tips, and NO was involved in this process.

  4. An Antifungal Role of Hydrogen Sulfide on the Postharvest Pathogens Aspergillus niger and Penicillium italicum

    PubMed Central

    Li, Yan-Hong; Hu, Liang-Bin; Yan, Hong; Liu, Yong-Sheng; Zhang, Hua

    2014-01-01

    In this research, the antifungal role of hydrogen sulfide (H2S) on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS) effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS) in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD) and catalase (CAT) genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation. PMID:25101960

  5. NO, hydrogen sulfide does not come first during tomato response to high salinity.

    PubMed

    da-Silva, Cristiane J; Mollica, Débora C F; Vicente, Mateus H; Peres, Lázaro E P; Modolo, Luzia V

    2017-09-28

    High salinity greatly impacts agriculture, particularly in tomato (Solanum lycopersicum), a crop that is a model to study this abiotic stress. This work investigated whether hydrogen sulfide (H2S) acts upstream or downstream of nitric oxide (NO) in the signaling cascade during tomato response to salt stress. An NO-donor incremented H2S levels by 12-18.9% while an H2S-donor yielded 10% more NO in roots. The NO accumulated in roots one-hour after NaCl treatment while H2S accumulation started two-hour later. The NO stimulated H2S accumulation in roots/leaves, but not the opposite (i.e H2S was unable to stimulate NO accumulation) two-hour post NaCl treatment. Also, NO accumulation was accompanied by an increment of transcript levels of genes that encode for H2S-synthesizing enzymes. Our results indicate that H2S acts downstream of NO in the mitigation of oxidative stress, which helps tomato plants to tolerate high salinity. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Hydrogen sulfide alleviates hypoxia-induced root tip death in Pisum sativum.

    PubMed

    Cheng, Wei; Zhang, Liang; Jiao, Chengjin; Su, Miao; Yang, Tao; Zhou, Lina; Peng, Renyi; Wang, Ranran; Wang, Chongying

    2013-09-01

    Flooding of soils often results in hypoxic conditions surrounding plant roots, which is a harmful abiotic stress to crops. Hydrogen sulfide (H2S) is a highly diffusible, gaseous molecule that modulates cell signaling and is involved in hypoxia signaling in animal cells. However, there have been no previous studies of H2S in plant cells in response to hypoxia. The effects of H2S on hypoxia-induced root tip death were studied in pea (Pisum sativum) via analysis of endogenous H2S and reactive oxygen species (ROS) levels. The activities of key enzymes involved in antioxidative and H2S metabolic pathways were determined using spectrophotometric assays. Ethylene was measured by gas chromatography. We found that exogenous H2S pretreatment dramatically alleviated hypoxia-induced root tip death by protecting root tip cell membranes from ROS damage induced by hypoxia and by stimulating a quiescence strategy through inhibiting ethylene production. Conversely, root tip death induced by hypoxia was strongly enhanced by inhibition of the key enzymes responsible for endogenous H2S biosynthesis. Our results demonstrated that exogenous H2S pretreatment significantly alleviates hypoxia-induced root tip death in pea seedlings and, therefore, enhances the tolerance of the plant to hypoxic stress. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Short-term effects of subchronic low-level hydrogen sulfide exposure on oil field workers.

    PubMed

    Mousa, Haider Abdul-Lateef

    2015-01-01

    To investigate the short-term effects of low-level hydrogen sulfide (H2S) exposure on oil field workers. Observational study included 34 patients who work at an oil field. All patients were males with age range of 22-60 years (mean 37 years). The data were collected by systematic questionnaire about symptoms. The inclusion criteria of patients were symptoms related to inhalation of H2S gas in the oil field. The complaints should be frequent and relapsed after each gas exposure and disappeared when there was no gas exposure. Exclusion criteria were the symptoms which experienced with or without H2S exposure. The presence of H2S gas was confirmed by valid gas detector devices. The most frequent presenting symptom was nasal bleeding. It was revealed in 18 patients (52.9%). This followed by pharyngeal bleeding, gum bleeding, and bloody saliva (mouth bleeding) which were encountered in five cases for each complaint (14.7%). Other less frequent presenting symptoms were tongue bleeding, bloody sputum, headache, abdominal colic, pharyngeal soreness, fatigue, and sleepiness. Nasal mucosa was the most vulnerable part to H2S effect. Inhalation of H2S produced upper respiratory tract epithelial damage that led to bleeding from nose, pharynx, gum, tongue, trachea, and bronchi. There were no complaints of asthmatic attack upon exposure to low level of H2S. Sunlight had a significant role in reduction of ambient air H2S level.

  8. Middle-thermophilic sulfur-oxidizing bacteria Thiomonas sp. RAN5 strain for hydrogen sulfide removal.

    PubMed

    Asano, Ryoki; Hirooka, Kayako; Nakai, Yutaka

    2012-01-01

    Hydrogen sulfide (H2S) is one of the most toxic and offensively odorous gases and is generated in anaerobic bioreactors. A middle-thermophilic sulfur-oxidizing bacterium (SOB), Thiomonas sp. strain RAN5, was isolated and applied for H2S removal from both artificial and anaerobically digested gas. When a bioreactor containing medium inoculated with RAN5 was aerated continuously with artificial gas (containing 100 ppm H2S) at 45 degrees C for 156 hr, the H2S concentration in the vented gas was reduced by 99%. This was not affected by the presence of other microbes in the bioreactor The H2S removal efficiency of the RAN5 bioreactor for anaerobically digested gas was greater than 99% at influent H2S concentrations ranging from 2 to 1800 ppm; the efficiency decreased to 90% at influent H2S concentrations greater than 2000 ppm. Thiomonas sp. strain RAN5 cannot survive at room temperature, and thus its leakage from a wastewater treatment plant would not damage sewage systems. These data suggest that Thiomonas sp. strain RAN5 may be a useful microorganism for H2S removal.

  9. Postural orthostatic tachycardia syndrome with increased erythrocytic hydrogen sulfide and response to midodrine hydrochloride.

    PubMed

    Yang, Jinyan; Zhao, Juan; Du, Shuxu; Liu, Die; Fu, Chunhin; Li, Xueying; Chen, Stella; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2013-10-01

    To evaluate the use of erythrocytic hydrogen sulfide (H2S) in predicting the therapeutic efficacy of midodrine hydrochloride for children with postural orthostatic tachycardia syndrome (POTS). Fifty-five children were included in this study, involving 28 children with POTS (POTS group) and 27 healthy children (control group). Children in the POTS group received midodrine hydrochloride treatment. Erythrocytic H2S production was measured; a receiver operating characteristic curve was used to assess if erythrocytic H2S could predict the therapeutic response to midodrine hydrochloride treatment. H2S production from erythrocytes was significantly higher in the POTS group than in the control group (P < .01). H2S production was also significantly higher in responders to midodrine hydrochloride than in non-responders (P < .05). The change in symptom score and baseline erythrocytic H2S production had a positive linear relationship (P < .01). There was also a positive correlation with the change in heart rate (P < .05). The receiver operating characteristic curve showed an area under curve value of 0.813. Erythrocytic H2S production yielded a sensitivity of 78.9% and a specificity of 77.8% in predicting the efficacy of midodrine hydrochloride therapy for children with POTS. Erythrocytic H2S could serve as a useful predictor of therapeutic response to midodrine hydrochloride in children with POTS. Copyright © 2013 Mosby, Inc. All rights reserved.

  10. Measurement of low concentration and nano-quantity hydrogen sulfide in sera using unfunctionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Wu, X. C.; Zhang, W. J.; Sammynaiken, R.; Meng, Q. H.; Wu, D. Q.; Yang, Q.; Yang, W.; Zhang, Edwin M.; Wang, R.

    2009-10-01

    Hydrogen sulfide (H2S) is produced in small amounts by certain cells in the mammalian body and has a number of biological functions. H2S gas naturally produced by the body is not simply a toxic gas; it could be a vascular dilator and play a physiological role in regulating cardiovascular functions. In order to know the effects of H2S, it is necessary to accurately know its concentrations in the body. Conventional measurement methods have their limitations concerning the small amount and low concentration of H2S in the body. A new paradigm of using carbon nanotubes in H2S measurement expresses its potential. However, the influence of proteins in the mammalian body must be studied in the measurement of H2S by carbon nanotubes. In this paper, we demonstrate a successful measurement of low concentration (20 µM) and nano-quantity (0.5 µg) H2S in the serum by using carbon nanotubes and further with the fluorescence of confocal laser scanning microscopy and the luminescence of Raman microscopy. Statistical analysis of the experimental data shows that the relationship between concentrations and intensities is linear, which thus makes the carbon nanotube sensor highly promising for the measurement of H2S in sera.

  11. Pharmacological Actions of Hydrogen Sulfide Donors on Sympathetic Neurotransmission in the Bovine Anterior Uvea, In Vitro.

    PubMed

    Salvi, Ankita; Bankhele, Pratik; Jamil, Jamal M; Kulkarni-Chitnis, Madhura; Njie-Mbye, Ya Fatou; Ohia, Sunny E; Opere, Catherine A

    2016-05-01

    In the present study, we investigated the effect of three different sources of hydrogen sulfide (H2S) on sympathetic neurotransmission from isolated superfused bovine iris-ciliary bodies. The three agents under consideration were: ACS67, a hybrid of latanoprost and a H2S-donating moiety; L-cysteine, a substrate for endogenous production of H2S and GYY 4137, a slow donor of H2S. We also examined the contribution of prostaglandins to the pharmacological actions of the H2S donors on release of [(3)H]-norepinephrine ([(3)H]NE) triggered by electrical field stimulation. ACS67, L-cysteine and GYY 4137 caused a concentration-dependent inhibition of electrically-evoked [(3)H]NE release from isolated bovine iris-ciliary bodies without affecting basal [(3)H]NE efflux. The cyclooxygenase inhibitor, flurbiprofen enhanced the inhibitory action of ACS67 and L-cysteine on stimulated [(3)H]NE release. Both aminooxyacetic acid, an inhibitor of cystathionine-β-synthase and glibenclamide, a KATP channel blocker reversed the inhibition of evoked NE release induced by the H2S donors. We conclude that H2S donors can inhibit sympathetic neurotransmission from isolated bovine iris-ciliary bodies, an effect partially dependent on the in situ production of H2S and prostanoids, and is mediated by an action on KATP channels.

  12. The influence of hydrogen sulfide on proton exchange membrane fuel cell anodes

    NASA Astrophysics Data System (ADS)

    Shi, Weiyu; Yi, Baolian; Hou, Ming; Jing, Fenning; Yu, Hongmei; Ming, Pingwen

    The effect of hydrogen sulfide on proton exchange membrane fuel cell (PEMFC) anodes was studied by cyclic voltammetry (CV), potential steps and electrochemical impedance spectroscopy (EIS). The severity of the effect of H 2S varies depending on the H 2S concentration, current density and the cell temperature. The anode humidification does not impact the poisoning rate much when the anode is exposed to H 2S. The adsorption of H 2S on the anode is dissociative and this dissociation can produce adsorbed sulfur. The dissociation potential of H 2S was studied by potential steps, and the values of the dissociation potential are about 0.4 V at 90 °C, 0.5 V at 60 °C and 0.6 V at 30 °C, respectively. The adsorbed sulfur can be oxidized at a higher potential. During CV scans, two oxidation peaks for the adsorbed sulfur at 1.07 and 1.2 V were observed at 90 °C, however a single oxidation peak could be observed at 1.2 V at 60 °C and at 1.27 V at 30 °C. Application of EIS to a H 2S|H 2 half-cell shows that the charge transfer resistance increases when the anode is exposed to H 2S because of H 2S adsorption.

  13. Ferric Iron and Cobalt (III) compounds to safely decrease hydrogen sulfide in the body?

    PubMed

    Van de Louw, Andry; Haouzi, Philippe

    2013-08-10

    To sort out the putative roles of endogenous hydrogen sulfide (H2S) in clinical conditions wherein systemic inflammation or hypoxia is present, it becomes crucial to develop approaches capable of affecting H2S concentration that can be safely applied in humans. We have investigated a paradigm, which could achieve such a goal, using vitamin B12 (vit.B12), at the dose recommended in cyanide poisoning, and very low levels of methemoglobin (MetHb). Hydroxocobalamin in the plasma, supernatant of kidney, and heart tissue homogenates of rats that had received vit.B12 (140 mg.kg(-1) intravenous) was found in the μM range. Exogenous H2S (100 μM) added to the plasma or supernatants of these rats decreased at a significantly higher rate than in control rats. In the latter however a spontaneous oxidation of exogenous H2S occurred. In vitro, hydroxocobalamin solution (100 μM) decreased, within <2 min, an equimolar concentration of H2S by 80%. Three to five percent MetHb prevented H2S induced hyperventilation in vivo and decreased exogenous H2S in vitro by 25-40 μM within 30 s. Our observations lead to the hypothesis that innocuous levels of MetHb and vit.B12 could be a used as an effective and safe way to test the role of endogenous H2S in vivo.

  14. Hydrogen sulfide alleviates diabetic nephropathy in a streptozotocin-induced diabetic rat model.

    PubMed

    Zhou, Xiang; Feng, Yu; Zhan, Zhoubing; Chen, Jianchang

    2014-10-17

    Accumulating evidence has demonstrated that hydrogen sulfide (H2S) plays critical roles in the pathogenesis of chronic kidney diseases. This study was designed to investigate whether H2S has protective effects against diabetic nephropathy. Diabetic rats were induced by intraperitoneal injection of streptozotocin and administrated with H2S donor NaHS for 12 weeks. Rat glomerular mesangial cells were pretreated with NaHS or MAPK inhibitors (U0126, SP600125, and SB203580) prior to high glucose exposure, and cell proliferation was determined. Our findings suggest that H2S can improve renal function and attenuate glomerular basement membrane thickening, mesangial matrix deposition, and renal interstitial fibrosis in diabetic rats. H2S was found to reduce high glucose-induced oxidative stress by activating the Nrf2 antioxidant pathway and to exert anti-inflammatory effects by inhibiting NF-κB signaling. In addition, H2S reduced high glucose-induced mesangial cell proliferation by blockade of MAPK signaling pathways. Moreover, H2S was also found to inhibit the renin-angiotensin system in diabetic kidney. In conclusion, our study demonstrates that H2S alleviates the development of diabetic nephropathy by attenuating oxidative stress and inflammation, reducing mesangial cell proliferation, and inhibiting renin-angiotensin system activity.

  15. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes.

    PubMed

    Sun, Mei; Sun, Wenjie; Barlaz, Morton A

    2016-05-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H2S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H2S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H2S produced by different types of sulfur-containing wastes in a relatively fast (30days) and inexpensive (125mL serum bottles) batch assay. This study confirmed the toxic effect of H2S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H2S by base adsorption was effective for mitigating inhibition. H2S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8mLH2S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H2S yield. A 60day incubation in selected samples resulted in 39-86% additional sulfide production. H2S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H2S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the microbial sulfide production

  16. Hydrogen sulfide improves neural function in rats following cardiopulmonary resuscitation.

    PubMed

    Lin, Ji-Yan; Zhang, Min-Wei; Wang, Jin-Gao; Li, Hui; Wei, Hong-Yan; Liu, Rong; Dai, Gang; Liao, Xiao-Xing

    2016-02-01

    The alleviation of brain injury is a key issue following cardiopulmonary resuscitation (CPR). Hydrogen sulfide (H2S) is hypothesized to be involved in the pathophysiological process of ischemia-reperfusion injury, and exerts a protective effect on neurons. The aim of the present study was to investigate the effects of H2S on neural functions following cardiac arrest (CA) in rats. A total of 60 rats were allocated at random into three groups. CA was induced to establish the model and CPR was performed after 6 min. Subsequently, sodium hydrosulfide (NaHS), hydroxylamine or saline was administered to the rats. Serum levels of H2S, neuron-specific enolase (NSE) and S100β were determined following CPR. In addition, neurological deficit scoring (NDS), the beam walking test (BWT), prehensile traction test and Morris water maze experiment were conducted. Neuronal apoptosis rates were detected in the hippocampal region following sacrifice. After CPR, as the H2S levels increased or decreased, the serum NSE and S100β concentrations decreased or increased, respectively (P<0.0w. The NDS results of the NaHS group were improved compared with those of the hydroxylamine group at 24 h after CPR (P<0.05). In the Morris water maze experiment, BWT and prehensile traction test the animals in the NaHS group performed best and rats in the hydroxylamine group performed worst. At day 7, the apoptotic index and the expression of caspase-3 were reduced in the hippocampal CA1 region, while the expression of Bcl-2 increased in the NaHS group; and results of the hydroxylamine group were in contrast. Therefore, the results of the present study indicate that H2S is able to improve neural function in rats following CPR.

  17. Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

    PubMed Central

    Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

    2008-01-01

    Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures. PMID:18197303

  18. Hydrogen sulfide and proline cooperate to alleviate cadmium stress in foxtail millet seedlings.

    PubMed

    Tian, Baohua; Qiao, Zengjie; Zhang, Liping; Li, Hua; Pei, Yanxi

    2016-12-01

    Hydrogen sulfide (H2S) and some functional amino acids in crops have been involved in the defense system against heavy-metal pollution. Here we report the relationships and functions of H2S and proline to cadmium (Cd) stress. Sodium hydrosulfide (NaHS) pretreatment decreased the electrolytic leakage and the malondialdehyde and hydrogen peroxide contents while enhancing photosynthesis in Cd-treated seedlings. Furthermore, pretreatment with NaHS markedly exacerbated Cd-induced alterations in proline content, the activities of proline-5-carboxylate reductase (P5CR) and proline dehydrogenase (PDH), and the transcript levels of P5CR and PDH. When endogenous H2S was scavenged or inhibited by various H2S modulators, the Cd-induced increase in endogenous proline was weakened. Combined pretreatment with H2S and proline was moderately higher in the Cd-stressed growth status, stomata movements and oxidative damage of seedlings compared to a single treatment with H2S or proline. These results suggest that H2S and proline cooperate to alleviate Cd-damage in foxtail millet.

  19. l-Cys/CSE/H2S pathway modulates mouse uterus motility and sildenafil effect.

    PubMed

    Mitidieri, Emma; Tramontano, Teresa; Donnarumma, Erminia; Brancaleone, Vincenzo; Cirino, Giuseppe; D Emmanuele di Villa Bianca, Roberta; Sorrentino, Raffaella

    2016-09-01

    Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, commonly used in the oral treatment for erectile dysfunction, relaxes smooth muscle of human bladder through the activation of hydrogen sulfide (H2S) signaling. H2S is an endogenous gaseous transmitter with myorelaxant properties predominantly formed from l-cysteine (l-Cys) by cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE). Sildenafil also relaxes rat and human myometrium during preterm labor but the underlying mechanism is still unclear. In the present study we investigated the possible involvement of H2S as a mediator of sildenafil-induced effect in uterine mouse contractility. We firstly demonstrated that both enzymes, CBS and CSE were expressed, and able to convert l-Cys into H2S in mouse uterus. Thereafter, sildenafil significantly increased H2S production in mouse uterus and this effect was abrogated by CBS or CSE inhibition. In parallel, l-Cys, sodium hydrogen sulfide or sildenafil but not d-Cys reduced spontaneous uterus contractility in a functional study. The blockage of CBS and CSE reduced this latter effect even if a major role for CSE than CBS was observed. This data was strongly confirmed by using CSE(-/-) mice. Indeed, the increase in H2S production mediated by l-Cys or by sildenafil was not found in CSE(-/-) mice. Besides, the effect of H2S or sildenafil on spontaneous contractility was reduced in CSE(-/-) mice. A decisive proof for the involvement of H2S signaling in sildenafil effect in mice uterus was given by the measurement of cGMP. Sildenafil increased cGMP level that was significantly reduced by CSE inhibition. In conclusion, l-Cys/CSE/H2S signaling modulates the mouse uterus motility and the sildenafil effect. Therefore the study may open different therapeutical approaches for the management of the uterus abnormal contractility disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. In-situ preparation of N-TiO2/graphene nanocomposite and its enhanced photocatalytic hydrogen production by H2S splitting under solar light

    NASA Astrophysics Data System (ADS)

    Bhirud, Ashwini P.; Sathaye, Shivaram D.; Waichal, Rupali P.; Ambekar, Jalindar D.; Park, Chan-J.; Kale, Bharat B.

    2015-03-01

    Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. ~5941 μmol h-1 under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to `N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst.Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully

  1. Occupationally related hydrogen sulfide deaths in the United States from 1984 to 1994.

    PubMed

    Fuller, D C; Suruda, A J

    2000-09-01

    Alice Hamilton described fatal work injuries from acute hydrogen sulfide poisonings in 1925 in her book Industrial Poisons in the United States. There is no unique code for H2S poisoning in the International Classification of Diseases, 9th Revision; therefore, these deaths cannot be identified easily from vital records. We reviewed US Occupational Safety and Health Administration (OSHA) investigation records for the period 1984 to 1994 for mention of hazardous substance 1480 (hydrogen sulfide). There were 80 fatalities from hydrogen sulfide in 57 incidents, with 19 fatalities and 36 injuries among coworkers attempting to rescue fallen workers. Only 17% of the deaths were at workplaces covered by collective bargaining agreements. OSHA issued citations for violation of respiratory protection and confined space standards in 60% of the fatalities. The use of hydrogen sulfide detection equipment, air-supplied respirators, and confined space safety training would have prevented most of the fatalities.

  2. Hydrogen sulfide activates the carotid body chemoreceptors in cat, rabbit and rat ex vivo preparations.

    PubMed

    Jiao, Yingfu; Li, Qian; Sun, Biying; Zhang, Guohua; Rong, Weifang

    2015-03-01

    We and others previously reported experimental evidence suggesting an important role for hydrogen sulfide (H2S) in oxygen sensing in murine carotid body chemoreceptors. More recent data implicated abnormal H2S-mediated chemoreceptor signaling in pathological conditions such as chronic heart failure and hypertension. However, the idea of H2S as a mediator of oxygen-sensing in chemoreceptors has been challenged. In particular, it was shown that exogenous H2S inhibited the release of neurotransmitters (ACh and ATP) from the cat carotid body, raising the possibility that there exists significant species difference in H2S-mediated signaling in chemoreceptors. This study was designed specifically to determine the effect of H2S on chemoreceptors in different species. We conducted multiunit extracellular recordings of the sinus nerve in the ex vivo carotid body preparation taken from the rat, the cat and the rabbit. As observed in the mouse carotid body, H2S donors (NaHS or Na2S) evoked qualitatively similar excitatory responses of the afferent sinus nerves of the species studied here. The excitatory effects of the H2S donors were concentration-dependent and reversible. The sinus nerve responses to H2S donors were prevented by blockade of the transmission between type I cells and the afferent terminals, as was the response to hypoxia. These results demonstrate that exogenous H2S exerts qualitatively similar excitatory effects on chemoreceptor afferents of different species. The role of endogenous H2S-mediated signaling in carotid body function in different species awaits further investigation.

  3. Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function.

    PubMed

    Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

    2011-08-16

    The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H(2)S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro "hyperglycemia") induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H(2)S. Replacement of H(2)S or overexpression of the H(2)S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H(2)S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H(2)S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE(-/-) mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H(2)S; replacement of H(2)S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H(2)S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H(2)S catabolism form a positive feed-forward cycle. H(2)S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function.

  4. Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function

    PubMed Central

    Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

    2011-01-01

    The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H2S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro “hyperglycemia”) induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H2S. Replacement of H2S or overexpression of the H2S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H2S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H2S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE−/− mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H2S; replacement of H2S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H2S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H2S catabolism form a positive feed-forward cycle. H2S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function. PMID:21808008

  5. FRET ratiometric probes reveal the chiral-sensitive cysteine-dependent H2S production and regulation in living cells

    NASA Astrophysics Data System (ADS)

    Wei, Lv; Yi, Long; Song, Fanbo; Wei, Chao; Wang, Bai-Fan; Xi, Zhen

    2014-04-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous signalling molecule with multiple biological functions. In order to visualize and quantify the endogenous in situ production of H2S in living cells, here we developed two new sulphide ratiometric probes (SR400 and SR550) based on fluorescence resonance energy transfer (FRET) strategy for live capture of H2S. The FRET-based probes show excellent selectivity toward H2S in a high thiol background under physiological buffer. The probe can be used to in situ visualize cysteine-dependent H2S production in a chiral-sensitive manner in living cells. The ratiometric imaging studies indicated that D-Cys induces more H2S production than that of L-Cys in mitochondria of human embryonic kidney 293 cells (HEK293). The cysteine mimics propargylglycine (PPG) has also been found to inhibit the cysteine-dependent endogenous H2S production in a chiral-sensitive manner in living cells. D-PPG inhibited D-Cys-dependent H2S production more efficiently than L-PPG, while, L-PPG inhibited L-Cys-dependent H2S production more efficiently than D-PPG. Our bioimaging studies support Kimura's discovery of H2S production from D-cysteine in mammalian cells and further highlight the potential of D-cysteine and its derivatives as an alternative strategy for classical H2S-releasing drugs.

  6. Involvement of hydrogen sulfide and homocysteine transsulfuration pathway in the progression of kidney fibrosis after ureteral obstruction.

    PubMed

    Jung, Kyong-Jin; Jang, Hee-Seong; Kim, Jee In; Han, Sang Jun; Park, Jeen-Woo; Park, Kwon Moo

    2013-12-01

    Hydrogen sulfide (H2S) produced by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) in the transsulfuration pathway of homocysteine plays a number of pathophysiological roles. Hyperhomocysteinemia is involved in kidney fibrosis. However, the role of H2S in kidney fibrosis remains to be defined. Here, we investigated the role of H2S and its acting mechanism in unilateral ureteral obstruction (UO)-induced kidney fibrosis in mice. UO decreased expressions of CBS and CSE in the kidney with decrease of H2S concentration. Treatment with sodium hydrogen sulfide (NaHS, a H2S producer) during UO reduced UO-induced oxidative stress with preservations of catalase, copper-zinc superoxide dismutase (CuZnSOD), and manganese superoxide dismutase (MnSOD) expression, and glutathione level. In addition, NaHS mitigated decreases of CBS and CSE expressions, and H2S concentration in the kidney. NaHS treatment attenuated UO-induced increases in levels of TGF-β1, activated Smad3, and activated NF-κB. This study provided the first evidence of involvement of the transsulfuration pathway and H2S in UO-induced kidney fibrosis, suggesting that H2S and its transsulfuration pathway may be a potential target for development of therapeutics for fibrosis-related diseases.

  7. Functional and Molecular Insights of Hydrogen Sulfide Signaling and Protein Sulfhydration.

    PubMed

    Sen, Nilkantha

    2017-02-17

    Hydrogen sulfide (H2S), a novel gasotransmitter, is endogenously synthesized by multiple enzymes that are differentially expressed in the peripheral tissues and central nervous systems. H2S regulates a wide range of physiological processes, namely cardiovascular, neuronal, immune, respiratory, gastrointestinal, liver, and endocrine systems, by influencing cellular signaling pathways and sulfhydration of target proteins. This review focuses on the recent progress made in H2S signaling that affects mechanistic and functional aspects of several biological processes such as autophagy, inflammation, proliferation and differentiation of stem cell, cell survival/death, and cellular metabolism under both physiological and pathological conditions. Moreover, we highlighted the cross-talk between nitric oxide and H2S in several bilogical contexts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effects of 10-ppm hydrogen sulfide inhalation on pulmonary function in healthy men and women.

    PubMed

    Bhambhani, Y; Burnham, R; Snydmiller, G; MacLean, I; Lovlin, R

    1996-10-01

    This study examined the acute effects of oral inhalation of 10-ppm hydrogen sulfide (H2S) inhalation (a concentration equal to its occupational exposure limit) on the pulmonary function in healthy men and women. Nine men and ten women consented to inhale medical air or 10 ppm H2S for 15 minutes each during cycle exercise at 50% of their maximal aerobic power. Routine pulmonary function tests were administered at rest and immediately after the two exposure conditions. The results indicated no significant changes in any of the variables derived from the flow volume loop, maximum ventilation volume, and diffusion capacity of the lung for carbon monoxide in both genders. None of the subjects experienced any signs and symptoms as a result of H2S exposure. It was concluded that oral inhalation of 10 ppm H2S at an elevated metabolic and ventilation rate does not significantly alter pulmonary function in healthy men and women.

  9. A Case of Survival: Myocardial Infarction and Ventricular Arrhythmia Induced by Severe Hydrogen Sulfide Poisoning.

    PubMed

    Chen, Jie; Chen, Shenjie; Mao, Wei

    2016-01-01

    Most cases of acute hydrogen sulfide (H2S) poisoning in China are caused by sewage processing. With the rapid development of urbanization in China, H2S poisoning is showing an increasing trend. Here, we report a case of survival from severe H2S poisoning. A 40-year-old worker was found in the underground sewer lines. He was unresponsive with bilaterally dilated pupils and had poor oxygen saturation. After intubation, he was transferred to the intensive care unit. He developed respiratory failure, acute myocardial infarction, ventricular arrhythmia and left ventricular function impairment, requiring artificial ventilation with highly concentrated oxygen, hyperbaric oxygen treatment and drug therapy. Consequently, he completely recovered from the respiratory and cardiac failure. Cases of survival after severe H2S intoxication have been rarely reported. Such exposures may bring about severe myocardial impairment, which is most likely to benefit from angiotensin-converting enzyme inhibition and β-blocker.

  10. GYY4137, a novel water-soluble, H2S-releasing molecule.

    PubMed

    Rose, Peter; Dymock, Brian W; Moore, Philip K

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as the so called "third gasotransmitter" taking its place alongside nitric oxide and carbon monoxide. In recent years, H2S has been reported to exhibit a diverse range of pharmacological effects in biological systems. Much of this evidence is derived from a combination of conventional pharmacological and genetic approaches coupled with the use of chemical compounds such as sodium hydrosulfide, a rapid H2S releasing donor. Developments in the design of new drug entities which attempt to take into account physicochemical properties, targeting to specific cellular organelles, triggering of H2S release upon specific chemical reactions in the cell, and controlling the release of H2S over extended periods of time have been described. For most of these molecules, little or no work has been conducted to determine their biological activity or possible therapeutic effects. It is therefore not clear whether such molecules have therapeutic potential which highlights the need for further in vivo studies. One exception to the general rule is GYY4137 (morpholin-4-ium 4-methoxyphenyl(morpholino) phosphinodithioate), a slow releasing H2S donor, which has been evaluated for activity in a range of pharmacological models both in vitro and in vivo. GYY4137 was first reported to release H2S and exhibit vasodilator activity over 5 years ago and, to date, GYY4137 is becoming increasingly employed as a pharmacological "tool" to explore the biological functions of H2S.

  11. Epithelial sodium channel is involved in H2S-induced acute pulmonary edema.

    PubMed

    Jiang, Lei; Wang, Yixin; Su, Chenglei; Sun, Hao; Zhang, Huazhong; Zhu, Baoli; Zhang, Hengdong; Xiao, Hang; Wang, Jun; Zhang, Jinsong

    2015-01-01

    Acute pulmonary edema is one of the major outcomes of exposure to high levels of hydrogen sulfide (H2S). However, the mechanisms involved in H2S-induced acute pulmonary edema are still poorly understood. Therefore, the present study is designed to evaluate the role of epithelial sodium channel (ENaC) in H2S-induced acute pulmonary edema. The Sprague-Dawley rats were exposed to sublethal concentrations of inhaled H2S, then the pulmonary histological and lung epithelial cell injury were evaluated by hematoxylin-eosin staining and electron microscopy, respectively. In addition to morphological investigation, our results also revealed that H2S exposure significantly decreased the alveolar fluid clearance and increased the lung tissue wet-dry ratio. These changes were demonstrated to be associated with decreased ENaC expression. Furthermore, the extracellular-regulated protein kinases 1/2 pathway was demonstrated to be implicated in H2S-mediated ENaC expression, because PD98059, an ERK1/2 antagonist, significantly mitigated H2S-mediated ENaC down-regulation. Therefore, our results show that ENaC might represent a novel pharmacological target for the treatment of acute pulmonary edema induced by H2S and other hazardous gases.

  12. H2S Loss through Nalophan™ Bags: Contributions of Adsorption and Diffusion.

    PubMed

    Eusebio, Lidia; Capelli, Laura; Sironi, Selena

    2017-01-01

    Hydrogen-sulfide (H2S) is a molecule of small dimensions typically present in the odor emissions from different plants. The European Standard EN 13725:2003 set a maximum storage time allowed of 30 hours, during which the sampling bag has to maintain the mixture of odorants with minimal changes. This study investigates the H2S losses through Nalophan bags and it shows that nonnegligible losses of H2S can be observed. The percent H2S loss after 30 hrs with respect to the initial concentration is equal to 33%  ± 3% at a relative humidity of 20% and equal to 22%  ± 1% at a relative humidity of 60%. The average quantity of adsorbed H2S at 30 h is equal to 2.17 10(5) gH2S/gNalophan at a storage humidity of 20% and equal to 1.79 10(5) gH2S/gNalophan at a storage humidity of 60%. The diffusion coefficients of H2S through Nalophan, for these two humidity conditions tested, are comparable (i.e., 7.5 10(-12) m(2)/sec at 20% humidity and 6.6 10(-12) m(2)/sec at 60% humidity).

  13. H2S Loss through Nalophan™ Bags: Contributions of Adsorption and Diffusion

    PubMed Central

    2017-01-01

    Hydrogen-sulfide (H2S) is a molecule of small dimensions typically present in the odor emissions from different plants. The European Standard EN 13725:2003 set a maximum storage time allowed of 30 hours, during which the sampling bag has to maintain the mixture of odorants with minimal changes. This study investigates the H2S losses through Nalophan bags and it shows that nonnegligible losses of H2S can be observed. The percent H2S loss after 30 hrs with respect to the initial concentration is equal to 33%  ± 3% at a relative humidity of 20% and equal to 22%  ± 1% at a relative humidity of 60%. The average quantity of adsorbed H2S at 30 h is equal to 2.17 105 gH2S/gNalophan at a storage humidity of 20% and equal to 1.79 105 gH2S/gNalophan at a storage humidity of 60%. The diffusion coefficients of H2S through Nalophan, for these two humidity conditions tested, are comparable (i.e., 7.5 10−12 m2/sec at 20% humidity and 6.6 10−12 m2/sec at 60% humidity). PMID:28740857

  14. H2S protects against fatal myelosuppression by promoting the generation of megakaryocytes/platelets.

    PubMed

    Liu, Huan-Di; Zhang, Ai-Jie; Xu, Jing-Jing; Chen, Ying; Zhu, Yi-Chun

    2016-02-24

    Our previous pilot studies aimed to examine the role of hydrogen sulfide (H2S) in the generation of endothelial progenitor cells led to an unexpected result, i.e., H2S promoted the differentiation of certain hematopoietic stem/progenitor cells in the bone marrow. This gave rise to an idea that H2S might promote hematopoiesis. To test this idea, a mice model of myelosuppression and cultured fetal liver cells were used to examine the role of H2S in hematopoiesis. H2S promoted the generation of megakaryocytes, increased platelet levels, ameliorate entorrhagia, and improved survival. These H2S effects were blocked in both in vivo and in vitro models with thrombopoietin (TPO) receptor knockout mice (c-mpl(-/-) mice). In contrast, H2S promoted megakaryocytes/platelets generation in both in vivo and in vitro models with TPO knockout mice (TPO(-/-) mice). H2S is a novel promoter for megakaryopoiesis by acting on the TPO receptors but not TPO to generate megakaryocytes/platelets.

  15. Novel H2S Releasing Nanofibrous Coating for In Vivo Dermal Wound Regeneration.

    PubMed

    Wu, Jiang; Li, Yi; He, Chaochao; Kang, Jianming; Ye, Jingjing; Xiao, Zecong; Zhu, Jingjing; Chen, Anqi; Feng, Sheng; Li, Xiaokun; Xiao, Jian; Xian, Ming; Wang, Qian

    2016-10-07

    Hydrogen sulfide (H2S), together with nitric oxide and carbon monoxide, has been recognized as an important gasotransmitter. It plays an essential physiological role in regulating cyto-protective signal process, and H2S-based therapy is considered as the next generation of promising therapeutic strategies for many biomedical applications, such as the treatment of cardiovascular disease. Through electrospinning of polycaprolactone (PCL) containing JK1, a novel pH-controllable H2S donor, nanofibers with H2S releasing function, PCL-JK1, are fabricated. This fibrous scaffold showed a pH-dependent H2S releasing behavior, i.e., lower pH induced greater and faster H2S release. In addition, the H2S release of JK1 was prolonged by the fibrous matrix as shown by decreased releasing rates compared to JK1 in solutions. In addition, in vitro studies indicated that PCL-JK1 exhibited excellent cyto-compatibility, similar to PCL fibers. Finally, we investigated PCL-JK1 as a wound dressing toward a cutaneous wound model in vivo and found that PCL-JK1 could significantly enhance the wound repair and regeneration compared with the control PCL scaffold, likely due to the release of H2S, which results in a broad range of physiologically protective functions toward the wound.

  16. [The effect of hydrogen sulfide on contractile activity of the vascular smooth muscles in rats].

    PubMed

    Semenykhina, O M; Baziliuk, O V; Korkach, Iu P; Sahach, V F

    2011-01-01

    The effect of endogenous and exogenous hydrogen sulfide (H2S) on contractile activity of vascular smooth muscle (VSM) was studied. The introduction of substrate synthesis H2S L-cysteine and its donor NaHS in vitro caused concentration-dependent relaxation of VSM of aorta and portal vein. Low concentrations of hydrogen sulfide donor (10(-5) mol/L) caused vasoconstriction of both types of the vessels. It was shown that the reaction of relaxation of VSM in response to NaHS is independent from endothelium. It was revealed that VSM of portal vein are more sensitive to the effects of H2S than VSM of aorta. Removing of aorta periadventitial adipose tissue showed no relaxation reply to the hydrogen sulfide donor NaHS in 70% of experiments. Some of the cellular mechanisms of hydrogen sulfide action were established, namely relaxation of aorta is depended on K(ATP) channel activation. This is manifested by a lack of relaxation of the aortic VSM due to K(ATP) channel inhibitor glibenclamide.

  17. Suicide by hydrogen sulfide inhalation.

    PubMed

    Bott, Eleanor; Dodd, Malcolm

    2013-03-01

    The authors report a case of suicide by hydrogen sulfide in Australia. A young woman was located in a car wearing protective eyewear. A tub of foamy yellow substance and a quantity of hydrochloric acid and lime sulfur were also located in the rear of the vehicle. Morphological findings at autopsy were nonspecific. Toxicologic analysis of a specimen of leg blood detected elevated levels of methemoglobin. If Australia follows a similar trend to Japan and the United States, it is possible that incidences of such cases will rise, probably because of Internet dissemination. From a public health perspective, emergency service providers and forensic case workers should be aware of the potential hazards to themselves and others when dealing with such cases.

  18. Clinical Implication of Plasma Hydrogen Sulfide Levels in Japanese Patients with Type 2 Diabetes

    PubMed Central

    Suzuki, Kunihiro; Sagara, Masaaki; Aoki, Chie; Tanaka, Seiichi; Aso, Yoshimasa

    2017-01-01

    Objective The goal of the present study was to investigate the plasma hydrogen sulfide (H2S) levels in patients with type 2 diabetes, as the plasma H2S levels in Japanese patients with type 2 diabetes remain unclear. Methods The plasma H2S levels were measured in 154 outpatients with type 2 diabetes and 66 outpatients without diabetes. All blood samples were collected in the outpatient department from 09:00 to 10:00. The patients had fasted from 21:00 the previous evening and had not consumed alcohol or caffeine or smoked until sample collection. The plasma H2S levels were measured using the methylene blue assay. The plasma H2S levels were determined in triplicate, and the average concentrations were calculated against a calibration curve of sodium sulfide. Results The patients with type 2 diabetes showed a progressive reduction in the plasma H2S levels (45.1±15.5 μM versus 54.0±26.4 μM, p<0.05), which paralleled poor glycemic control. There was a significant correlation between a reduction in the plasma H2S levels and the HbA1c levels (β=-0.505, p<0.01), Furthermore, a reduction in the plasma H2S levels was found to be related to a history of cardiovascular diseases in patients with type 2 diabetes (39.9±13.8 μM versus 47.5±15.9 μM, p<0.01). Conclusion Collectively, the plasma H2S levels were reduced in patients with type 2 diabetes, which may have implications in the pathophysiology of cardiovascular disease in diabetic patients. The trial was registered with the University Hospital Medical Information Network (UMIN no. #000020549). PMID:28049995

  19. The Effect of Hydrogen Sulfide Donors on Lipopolysaccharide-Induced Formation of Inflammatory Mediators in Macrophages

    PubMed Central

    Whiteman, Matthew; Li, Ling; Rose, Peter; Tan, Choon-Hong; Parkinson, David B.

    2010-01-01

    Abstract The role of hydrogen sulfide (H2S) in inflammation is controversial, with both pro- and antiinflammatory effects documented. Many studies have used simple sulfide salts as the source of H2S, which give a rapid bolus of H2S in aqueous solutions and thus do not accurately reflect the enzymatic generation of H2S. We therefore compared the effects of sodium hydrosulfide and a novel slow-releasing H2S donor (GYY4137) on the release of pro- and antiinflammatory mediators in lipopolysaccharide (LPS)-treated murine RAW264.7 macrophages. For the first time, we show that GYY4137 significantly and concentration-dependently inhibits LPS-induced release of proinflammatory mediators such as IL-1β, IL-6, TNF-α, nitric oxide (•NO), and PGE2 but increased the synthesis of the antiinflammatory chemokine IL-10 through NF-κB/ATF-2/HSP-27–dependent pathways. In contrast, NaHS elicited a biphasic effect on proinflammatory mediators and, at high concentrations, increased the synthesis of IL-1β, IL-6, NO, PGE2 and TNF-α. This study clearly shows that the effects of H2S on the inflammatory process are complex and dependent not only on H2S concentration but also on the rate of H2S generation. This study may also explain some of the apparent discrepancies in the literature regarding the pro- versus antiinflammatory role of H2S. Antioxid. Redox Signal. 12, 1147–1154. PMID:19769459

  20. A Distal Ligand Mutes the Interaction of Hydrogen Sulfide with Human Neuroglobin.

    PubMed

    Ruetz, Markus; Kumutima, Jacques; Lewis, Brianne E; Filipovic, Milos R; Lehnert, Nicolai; Stemmler, Timothy L; Banerjee, Ruma

    2017-02-28

    Hydrogen sulfide is a critical signaling molecule, but high concentrations cause cellular toxicity. A four-enzyme pathway in the mitochondrion detoxifies H2S by converting it to thiosulfate and sulfate. Recent studies have shown that globins like hemoglobin and myoglobin can also oxidize H2S to thiosulfate and hydropolysulfides. Neuroglobin, a globin enriched in brain, was reported to bind H2S tightly and postulated to play a role in modulating neuronal sensitivity to H2S in conditions such as stroke. However, the H2S reactivity of the coordinately saturated heme in neuroglobin is expected a priori to be substantially lower than that of the 5-coordinate hemes present in myoglobin and hemoglobin. To resolve this discrepancy, we explored the role of the distal histidine residue in muting the reactivity of human neuroglobin towards H2S. Ferric neuroglobin is slowly reduced by H2S and catalyzes its inefficient oxidative conversion to thiosulfate. Mutation of the distal His64 residue to alanine, promotes rapid binding of H2S and its efficient conversion to oxidized products. X-ray absorption, EPR and resonance Raman spectroscopy highlight the chemically different reaction options influenced by the distal histidine ligand. This study provides mechanistic insights into how the distal heme ligand in neuroglobin caps its reactivity towards H2S and identifies by cryo-mass spectrometry a range of sulfide oxidation products with 2-6 catenated sulfur atoms with or without oxygen insertion, which accumulate in the absence of the H64 ligand.

  1. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide-Rich Environments.

    PubMed

    Kelley, Joanna L; Arias-Rodriguez, Lenin; Patacsil Martin, Dorrelyn; Yee, Muh-Ching; Bustamante, Carlos D; Tobler, Michael

    2016-06-01

    Hydrogen sulfide (H2S) is a potent toxicant interfering with oxidative phosphorylation in mitochondria and creating extreme environmental conditions in aquatic ecosystems. The mechanistic basis of adaptation to perpetual exposure to H2S remains poorly understood. We investigated evolutionarily independent lineages of livebearing fishes that have colonized and adapted to springs rich in H2S and compared their genome-wide gene expression patterns with closely related lineages from adjacent, nonsulfidic streams. Significant differences in gene expression were uncovered between all sulfidic and nonsulfidic population pairs. Variation in the number of differentially expressed genes among population pairs corresponded to differences in divergence times and rates of gene flow, which is consistent with neutral drift driving a substantial portion of gene expression variation among populations. Accordingly, there was little evidence for convergent evolution shaping large-scale gene expression patterns among independent sulfide spring populations. Nonetheless, we identified a small number of genes that was consistently differentially expressed in the same direction in all sulfidic and nonsulfidic population pairs. Functional annotation of shared differentially expressed genes indicated upregulation of genes associated with enzymatic H2S detoxification and transport of oxidized sulfur species, oxidative phosphorylation, energy metabolism, and pathways involved in responses to oxidative stress. Overall, our results suggest that modification of processes associated with H2S detoxification and toxicity likely complement each other to mediate elevated H2S tolerance in sulfide spring fishes. Our analyses allow for the development of novel hypotheses about biochemical and physiological mechanisms of adaptation to extreme environments. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Hydrogen sulfide mitigates matrix metalloproteinase-9 activity and neurovascular permeability in hyperhomocysteinemic mice.

    PubMed

    Tyagi, Neetu; Givvimani, Srikanth; Qipshidze, Natia; Kundu, Soumi; Kapoor, Shray; Vacek, Jonathan C; Tyagi, Suresh C

    2010-01-01

    An elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), was associated with neurovascular diseases. At physiological levels, hydrogen sulfide (H(2)S) protected the neurovascular system. Because Hcy was also a precursor of hydrogen sulfide (H(2)S), we sought to test whether the H(2)S protected the brain during HHcy. Cystathionine-beta-synthase heterozygous (CBS+/-) and wild type (WT) mice were supplemented with or without NaHS (30 microM/L, H(2)S donor) in drinking water. Blood flow and cerebral microvascular permeability in pial vessels were measured by intravital microscopy in WT, WT+NaHS, CBS-/+ and (CBS-/+)+NaHS-treated mice. The brain tissues were analyzed for matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) by Western blot and RT-PCR. The mRNA levels of CBS and cystathionine gamma lyase (CSE, enzyme responsible for conversion of Hcy to H(2)S) genes were measured by RT-PCR. The results showed a significant increase in MMP-2, MMP-9, TIMP-3 protein and mRNA in CBS (-/+) mice, while H(2)S treatment mitigated this increase. Interstitial localization of MMPs was also apparent through immunohistochemistry. A decrease in protein and mRNA expression of TIMP-4 was observed in CBS (-/+) mice. Microscopy data revealed increase in permeability in CBS (-/+) mice. These effects were ameliorated by H(2)S and suggested that physiological levels of H(2)S supplementation may have therapeutic potential against HHcy-induced microvascular permeability, in part, by normalizing the MMP/TIMP ratio in the brain.

  3. Hydrogen sulfide is essential for Schwann cell responses to peripheral nerve injury.

    PubMed

    Park, Byung Sun; Kim, Hyun-Wook; Rhyu, Im Joo; Park, Chan; Yeo, Seung Geun; Huh, Youngbuhm; Jeong, Na Young; Jung, Junyang

    2015-01-01

    Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from substances by three enzymes: cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (MST). In human tissues, these enzymes are involved in tissue-specific biochemical pathways for H2 S production. For example, CBS and cysteine aminotransferase/MST are present in the brain, but CSE is not. Thus, we examined the expression of H2 S production-related enzymes in peripheral nerves. Here, we found that CSE and MST/cysteine aminotransferase, but not CBS, were present in normal peripheral nerves. In addition, injured sciatic nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration (WD); however, CSE was not up-regulated in peripheral axons. Using an ex vivo sciatic nerve explant culture, we found that the inhibition of H2 S production broadly prevented the process of nerve degeneration, including myelin fragmentation, axonal degradation, Schwann cell dedifferentiation, and Schwann cell proliferation in vitro and in vivo. Thus, these results indicate that H2 S signaling is essential for Schwann cell responses to peripheral nerve injury. Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfur transferase (MST). Here, we found that CSE and MST/CAT were present in normal peripheral nerves. Injured static nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration, but CSE was not up-regulated in peripheral axons. © 2014 International Society for Neurochemistry.

  4. [Severe hydrogen sulfide intoxication: a pediatric case of survival].

    PubMed

    Claudet, I; Marcoux, M-O; Karsenty, C; Rittié, J-L; Honorat, R; Lelong-Tissier, M-C

    2012-03-01

    We report a paediatric case of survival following severe hydrogen sulfide (H2S) gas intoxication. A 13-year-old boy was found submerged to the neck in a manure tank. He was hypothermic, unresponsive with bilateral mydriasis, and had poor oxygen saturation. After intubation, he was transferred to the paediatric intensive care unit of a tertiary care children's hospital. He developed acute respiratory distress syndrome (ARDS) requiring high frequency percussive ventilation. Cardiac evaluation was significant for myocardial infarction and left ventricular function impairment. He completely recovered from the respiratory and cardiac failure. Neurological examinations showed abnormal signals on MRI in the semi-oval center and in the frontal cortex. Follow-up detected partial impairment of axonal fibers of the right external popliteal sciatic nerve. Paediatric cases of survival after H2S intoxication have been rarely reported. Such exposures can evolve to severe ARDS and benefit from high frequency percussive ventilation. Hypothermia and other metabolic abnormalities are now better explained thanks to actual knowledge about endogenous H2S function. Lessons learned from paediatric accidents should result in better information about this threat for farmers and families living in houses with septic tanks, reducing the risk to their own and their children's safety.

  5. Depolarizing Actions of Hydrogen Sulfide on Hypothalamic Paraventricular Nucleus Neurons

    PubMed Central

    Khademullah, C. Sahara; Ferguson, Alastair V.

    2013-01-01

    Hydrogen sulfide (H2S) is a novel neurotransmitter that has been shown to influence cardiovascular functions as well and corticotrophin hormone (CRH) secretion. Since the paraventricular nucleus of the hypothalamus (PVN) is a central relay center for autonomic and endocrine functions, we sought to investigate the effects of H2S on the neuronal population of the PVN. Whole cell current clamp recordings were acquired from the PVN neurons and sodium hydrosulfide hydrate (NaHS) was bath applied at various concentrations (0.1, 1, 10, and 50 mM). NaHS (1, 10, and 50 mM) elicited a concentration-response relationship from the majority of recorded neurons, with almost exclusively depolarizing effects following administration. Cells responded and recovered from NaHS administration quickly and the effects were repeatable. Input differences from baseline and during the NaHS-induced depolarization uncovered a biphasic response, implicating both a potassium and non-selective cation conductance. The results from the neuronal population of the PVN shed light on the possible physiological role that H2S has in autonomic and endocrine function. PMID:23691233

  6. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L.; Gorski, Anthony J.; Daniels, Edward J.

    1993-01-01

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  7. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  8. Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings

    PubMed Central

    Chen, Juan; Shang, Yu-Ting; Wang, Wen-Hua; Chen, Xi-Yan; He, En-Ming; Zheng, Hai-Lei; Shangguan, Zhouping

    2016-01-01

    Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance. PMID:27540388

  9. Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings.

    PubMed

    Chen, Juan; Shang, Yu-Ting; Wang, Wen-Hua; Chen, Xi-Yan; He, En-Ming; Zheng, Hai-Lei; Shangguan, Zhouping

    2016-01-01

    Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance.

  10. Structural effects of naphthalimide-based fluorescent sensor for hydrogen sulfide and imaging in live zebrafish

    NASA Astrophysics Data System (ADS)

    Choi, Seon-Ae; Park, Chul Soon; Kwon, Oh Seok; Giong, Hoi-Khoanh; Lee, Jeong-Soo; Ha, Tai Hwan; Lee, Chang-Soo

    2016-05-01

    Hydrogen sulfide (H2S) is an important biological messenger, but few biologically-compatible methods are available for its detection in aqueous solution. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe (L1), which is a highly versatile building unit that absorbs and emits at long wavelengths and is selective for hydrogen sulfide over cysteine, glutathione, and other reactive sulfur, nitrogen, and oxygen species in aqueous solution. We describe turn-on fluorescent probes based on azide group reduction on the fluorogenic ‘naphthalene’ moiety to fluorescent amines and intracellular hydrogen sulfide detection without the use of an organic solvent. L1 and L2 were synthetically modified to functional groups with comparable solubility on the N-imide site, showing a marked change in turn-on fluorescent intensity in response to hydrogen sulfide in both PBS buffer and living cells. The probes were readily employed to assess intracellular hydrogen sulfide level changes by imaging endogenous hydrogen sulfide signal in RAW264.7 cells incubated with L1 and L2. Expanding the use of L1 to complex and heterogeneous biological settings, we successfully visualized hydrogen sulfide detection in the yolk, brain and spinal cord of living zebrafish embryos, thereby providing a powerful approach for live imaging for investigating chemical signaling in complex multicellular systems.

  11. Structural effects of naphthalimide-based fluorescent sensor for hydrogen sulfide and imaging in live zebrafish

    PubMed Central

    Choi, Seon-Ae; Park, Chul Soon; Kwon, Oh Seok; Giong, Hoi-Khoanh; Lee, Jeong-Soo; Ha, Tai Hwan; Lee, Chang-Soo

    2016-01-01

    Hydrogen sulfide (H2S) is an important biological messenger, but few biologically-compatible methods are available for its detection in aqueous solution. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe (L1), which is a highly versatile building unit that absorbs and emits at long wavelengths and is selective for hydrogen sulfide over cysteine, glutathione, and other reactive sulfur, nitrogen, and oxygen species in aqueous solution. We describe turn-on fluorescent probes based on azide group reduction on the fluorogenic ‘naphthalene’ moiety to fluorescent amines and intracellular hydrogen sulfide detection without the use of an organic solvent. L1 and L2 were synthetically modified to functional groups with comparable solubility on the N-imide site, showing a marked change in turn-on fluorescent intensity in response to hydrogen sulfide in both PBS buffer and living cells. The probes were readily employed to assess intracellular hydrogen sulfide level changes by imaging endogenous hydrogen sulfide signal in RAW264.7 cells incubated with L1 and L2. Expanding the use of L1 to complex and heterogeneous biological settings, we successfully visualized hydrogen sulfide detection in the yolk, brain and spinal cord of living zebrafish embryos, thereby providing a powerful approach for live imaging for investigating chemical signaling in complex multicellular systems. PMID:27188400

  12. Adsorption and reaction of H2S on Cu(110) studied using scanning tunneling microscopy.

    PubMed

    Shiotari, Akitoshi; Okuyama, Hiroshi; Hatta, Shinichiro; Aruga, Tetsuya; Hamada, Ikutaro

    2016-02-14

    Using low-temperature scanning tunneling microscopy (STM), the adsorption and reaction of hydrogen sulfide (H2S) and its fragments (SH and S) on Cu(110) are investigated at 5 K. H2S adsorbs molecularly on the surface on top of a Cu atom. With voltage pulses of STM, it is possible to induce sequential dehydrogenation of H2S to SH and S. We found two kinds of adsorption structures of SH. The short-bridge site is the most stable site for SH, while the long-bridge site is the second. Density functional theory calculations show that the S-H axis is inclined from the surface normal for both species. The reaction of H2S with OH and O was directly observed to yield SH and S, respectively, providing a molecular-level insight into catalyst poisoning.

  13. A systematic review of occupational exposure to hydrogen sulfide in livestock operations.

    PubMed

    Guarrasi, Justene; Trask, Catherine; Kirychuk, Shelley

    2015-01-01

    This systematic review summarizes the current state of knowledge in hydrogen sulfide (H2S) concentrations within intensive livestock operations. The review was undertaken to better understand H2S concentrations in intensive livestock operations, in relation to the American Conference of Governmental Industrial Hygienists (ACGIH) limit reduction to a 1 ppm time-weighted average (TWA). Several online academic databases were searched using two conceptual groups of search terms: "livestock" and "hydrogen sulfide." Industry gray literature was additionally identified via targeted searches of online agriculture-specific Web sites. Title, abstract, and full-text screening were performed to select articles reporting H2S measurements made within livestock facilities. Forty-five articles were included in this review. The bulk (70%) of articles described swine operations, whereas the remaining represented poultry and dairy operations. Although 14% of the articles described task-based monitoring of H2S, the majority of articles (86%) involved only area monitoring. Weighted means from all three livestock types were below 1 ppm, although swine operations displayed a wider range of exposure (from 0 to 97 ppm). Despite most mean task-based exposures being close to 1 ppm, the peak concentrations measurements may be higher during power washing (97 ppm) and miscellaneous tasks (11.4 ppm). This review provides a novel overview of H2S levels in intensive livestock operations, including information on task-based measurements. The review highlights numerous influences that produce a wide variability of H2S levels in intensive livestock operations. The review also highlights the need for research focused on personal monitoring of daily worker exposures to hydrogen sulfide in intensive livestock operations.

  14. Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.

    PubMed

    Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

    2009-12-01

    Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media.

  15. A method for controlling hydrogen sulfide in water by adding solid phase oxygen.

    PubMed

    Chang, Yu-Jie; Chang, Yi-Tang; Chen, Hsi-Jien

    2007-01-01

    This work evaluates the addition of solid phase oxygen, a magnesium peroxide (MgO(2)) formulation manufactured by Regenesis (oxygen-releasing compounds, ORC), to inhibit the production of hydrogen sulfide (H(2)S) in an SRB-enriched environment. The initial rate of release of oxygen by the ORC was determined over a short period by adding sodium sulfite (Na(2)SO(3)), which was a novel approach developed for this study. The ability of ORCs to control H(2)S by releasing oxygen was evaluated in a bench-scale column containing cultured sulfate reducing bacteria (SRB). After a series of batch tests, 0.4% ORC was found to be able to inhibit the formation of H(2)S for more than 40 days. In comparison, the concentration of H(2)S dropped from 20 mg S/L to 0.05 mg S/L immediately after 0.1% hydrogen peroxide (H(2)O(2)) was added, but began to recover just four days later. Thus, H(2)O(2) does not seem to be able to inhibit the production of sulfide for an extended period of time. By providing long-term inhibition of the SRB population, ORC provides a good alternative means of controlling the production of H(2)S in water.

  16. Endogenous Hydrogen Sulfide Enhances Cell Proliferation of Human Gastric Cancer AGS Cells.

    PubMed

    Sekiguchi, Fumiko; Sekimoto, Teruki; Ogura, Ayaka; Kawabata, Atsufumi

    2016-01-01

    Hydrogen sulfide (H2S), the third gasotransmitter, is endogenously generated by certain H2S synthesizing enzymes, including cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) from L-cysteine in the mammalian body. Several studies have shown that endogenous and exogenous H2S affects the proliferation of cancer cells, although the effects of H2S appear to vary with cell type, being either promotive or suppressive. In the present study, we determined whether endogenously formed H2S regulates proliferation in human gastric cancer AGS cells. CSE, but not CBS, was expressed in AGS cells. CSE inhibitors, DL-propargylglycine (PPG) and β-cyano-L-alanine (BCA), significantly suppressed the proliferation of AGS cells in a concentration-dependent manner. CSE inhibitors did not increase lactate dehydrogenase (LDH) release in the same concentration range. The inhibitory effects of PPG and BCA on cell proliferation were reversed by repetitive application of NaHS, a donor of H2S. Interestingly, nuclear condensation and fragmentation were detected in AGS cells treated with PPG or BCA. These results suggest that endogenous H2S produced by CSE may contribute to the proliferation of gastric cancer AGS cells, most probably through anti-apoptotic actions.

  17. Emerging Roles of Hydrogen Sulfide in Inflammatory and Neoplastic Colonic Diseases

    PubMed Central

    Guo, Fang-Fang; Yu, Ta-Chung; Hong, Jie; Fang, Jing-Yuan

    2016-01-01

    Hydrogen sulfide (H2S) is a toxic gas that has been recognized as an important mediator of many physiological processes, such as neurodegeneration, regulation of inflammation, blood pressure, and metabolism. In the human colon, H2S is produced by both endogenous enzymes and sulfate-reducing bacteria (SRB). H2S is involved in the physiological and pathophysiological conditions of the colon, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), which makes the pharmacological modulation of H2S production and metabolism a potential chemical target for the treatment of colonic diseases. However, the exact mechanisms and pathways by which H2S-mediates normal physiological function and disease in the colon are not fully understood. Besides, the production and release of H2S are modulated by both endogenous and exogenous factors. This review will discuss the production and storage of H2S, its biological roles and the emerging importance in physiology and pathology of IBD and CRC. PMID:27199771

  18. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

    PubMed Central

    Shen, Yaqi; Shen, Zhuqing; Luo, Shanshan; Guo, Wei; Zhu, Yi Zhun

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for furth