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Hydrogen Sulphide (hydrogen + sulphide)

Distribution by Scientific Domains

Medical Sciences	65%
Life Sciences	15%
Chemistry	15%

Selected Abstracts

EFFECT OF HYDROGEN SULPHIDE ON ,-AMYLOID-INDUCED DAMAGE IN PC12 CELLS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 2 2008
Xiao-Qing Tang
SUMMARY 1Hydrogen sulphide (H2S) is a well-known cytotoxic gas. Recently, H2S has been shown to protect neurons against oxidative stress caused by glutamate, peroxynitrite and HOCl. Considerably lower H2S levels have been reported in the brain of Alzheimer's disease (AD) patients with accumulation of ,-amyloid (A,). 2The aim of present study was to explore the cytoprotection by H2S against A,25,35 -induced apoptosis and the molecular mechanisms underlying this effect in PC12 cells. 3Our findings indicated that A,25,35 significantly reduced cell viability and induced apoptosis of PC12 cells, along with dissipation of the mitochondrial membrane potential (MMP) and overproduction of reactive oxygen species (ROS). 4Sodium hydrosulphide (NaHS), an H2S donor, protected PC12 cells against A,25,35 -induced cytotoxicity and apoptosis not only by reducing the loss of MMP, but also by attenuating the increase in intracellular ROS. 5The results of the present study suggest that the cytoprotection by H2S is related to the preservation of MMP and attenuation of A,25,35 -induced intracellular ROS generation. These findings could significantly advance therapeutic approaches to the neurodegenerative diseases that are associated with oxidative stress, such as AD. [source]

2222: Hydrogen sulphide: a new CNS mediator

ACTA OPHTHALMOLOGICA, Issue 2010
N OSBORNE
The recent discovery that hydrogen sulphide (H2S) is an endogenously produced gaseous secondary messenger capable of modulating many physiological processes, much like nitric oxide, prompted us to investigate the potential role of H2S as a retinal neuroprotective agent. In the current study we use dithiolethiones (kindly provided by Dr. Piero Del Soldato, Milan, Italy) as H2S donors and show that such substances attenuate the effect of retinal ischemia as well as oxidative and light-induced injury to a transformed line of cells (RGC-5 cells) in culture. Ischemia was delivered to rats by elevation of the intraocular pressure above the systolic blood pressure. Partial damage to the retina after seven days was determined by a combination of procedures which included analysis of electroretinograms, immunohistochemistry and changes in the retinal content of proteins and mRNAs known to be associated with ganglion cell function and apoptosis. Most of the changes caused by ischemia were significantly attenuated by intravitreal injection of a H2S donor directly after ischemia. Both light (400-700nm, intensity 1000 lux) and hydrogen peroxide caused death to RGC-5 cells in culture over a period of 24-48 hours in a time and dose-dependent manner, respectively. Light and hydrogen peroxide-induced RGC-5 cell death is by different forms of apoptosis but they are both attenuated by the H2S donor, ACS1. These initial findings demonstrate that donors of H2S may be value in the treatment of various retinal dysfunctions where oxidative stress, light or ischemia is implicated as causative fact [source]

Significance of endogenous sulphur-containing gases in the cardiovascular system

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2010
Xin-Bao Wang
Summary 1. The sulphur-containing gases hydrogen sulphide and sulphur dioxide can be generated endogenously in mammalian tissues and exert significant biological effects in the cardiovascular system. Hydrogen sulphide is considered to be the third novel gasotransmitter in addition to nitric oxide and carbon monoxide. The present review describes the effects of hydrogen sulphide on the cardiovascular system and its possible mechanisms under physiological conditions. We also discuss the pathophysiological effects of hydrogen sulphide on cardiovascular diseases. The therapeutic potential of hydrogen sulphide is summarized. 2. We recently discovered that sulphur dioxide, another endogenous sulphur-containing gas, has important physiological and pathophysiological roles in the cardiovascular system. To some extent, the effect of sulphur dioxide is similar to that of the other gasotransmitters nitric oxide, carbon monoxide and hydrogen sulphide. Sulphur dioxide may also be a novel gas mediator in the cardiovascular system. [source]

Oxygen-dependent ion transport in erythrocytes

ACTA PHYSIOLOGICA, Issue 3 2009
A. Bogdanova
Abstract The present contribution reviews current knowledge of apparently oxygen-dependent ion transport in erythrocytes and presents modern hypotheses on their regulatory mechanisms and physiological roles. In addition to molecular oxygen as such, reactive oxygen species, nitric oxide, carbon monoxide, regional variations of cellular ATP and hydrogen sulphide may play a role in the regulation of transport, provided that they are affected by oxygen tension. It appears that the transporter molecules themselves do not have direct oxygen sensors. Thus, the oxygen level must be sensed elsewhere, and the effect transduced to the transporter. The possible pathways involved in the regulation of transport, including haemoglobin as a sensor, and phosphorylation/dephosphorylation reactions both in the transporter and its upstream effectors, are discussed. [source]

The role of cysteine and cysteine,S conjugates as odour precursors in the flavour and fragrance industry ,

FLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2008
Christian Starkenmann
Abstract Volatile sulphur compounds are important odorants in the flavour and fragrance industries. Recent developments in the field have reinvigorated sulphur compound research, particularly with regard to the precursor compounds of volatile thiols. The present review concentrates on the role of cysteine and cysteine,S conjugates as precursor compounds for a variety of aromas and examines the chemical and enzymatic pathways of degradation and biotransformation. Cysteine is an important source of sulphur in flavour chemistry and may be degraded into hydrogen sulphide, which can further participate in other reactions. Direct reactions of cysteine and the pathways particular to various flavours and fragrances are discussed, with an emphasis on the precursor compounds cysteine,S conjugates. The importance of cysteine precursors in plants, including onion, wine, passion fruit, bitter orange, asparagus and bell pepper and the formation of natural scents in cats and humans are discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Determination of the aroma impact compounds in heated sweet cream butter

FLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003
D. G. Peterson
Abstract This study was conducted to determine which volatile compounds are primarily responsible for the aroma of heated sweet cream butter. Static headspace analysis was used for aroma isolation and gas chromatography,olfactometry (GC,O) for the selection of odour-active components. Quanti,cation of selected odourants was done via purge and trap-GC/mass spectrometry (MS). Nineteen odour-active compounds were detected in the headspace (static) of heated butter (hydrogen sulphide, methanethiol, acetaldehyde, 2,3-butanedione, 1-hexen-3-one, butanoic acid, 3-methylbutanoic acid, 2-heptanone, methional, dimethyl trisulphide, 1-octen-3-one, hexanoic acid, furaneol, , -hexanolactone, nonanal, (E)-2-nonenal, , -octanolactone, skatole and , -decanolactone). Aroma recombination studies followed by sensory analysis indicated that the aroma of our heated butter model was rated the same (similarity) as a heated commercial butter (obtained from local market) in comparison to a heated freshly manufactured butter. The aroma of a heated commercial unsalted butter and a heated butter aroma model of Budin 1 also were signi,cantly less similar than the aroma of our heated butter model in comparison to a heated freshly manufactured butter. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Halitosis among racially diverse populations: an update

INTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 1 2008
S Rayman
Abstract:, The aim of this paper is to highlight the cultural perceptions of halitosis to dental professionals. Halitosis (oral malodour or bad breath) is caused mainly by tongue coating and periodontal disease. Bacterial metabolism of amino acids leads to metabolites including many compounds, such as indole, skatole and volatile sulphur compounds (VSC), hydrogen sulphide, methyl mercaptan and dimethyl sulphide. They are claimed to be the main aetiological agents for halitosis. Gastrointestinal diseases are also generally believed to cause halitosis. In general, physicians and dentists are poorly informed about the causes and treatments for halitosis. The paper reviews the prevalence and distribution of halitosis, oral malodour, its aetiology, concepts of general and oral health and diseases and their perception among racially diverse population. Eating, smoking and drinking habits and understanding of halitosis as a social norm among different people has been highlighted. The treatment options have also been presented very briefly. A brief discussion about general importance within existing healthcare services has been highlighted. Oral malodour may rank only behind dental caries and periodontal disease as the cause of patient's visits to the dentist. It is a public social health problem. The perception of halitosis is different in culturally diverse populations. So the dental professionals should be aware of the cultural perceptions of halitosis among racially and culturally diverse populations. There is a need to integrate the cultural awareness and knowledge about halitosis among the dental professional for better understanding of halitosis to treat patients with the social dilemma of halitosis to improve the quality of life and well-being of individuals with the problem. It is concluded that dental professionals (especially dental hygienists) should be prepared to practice in a culturally diverse environment in a sensitive and appropriate manner, to deliver optimal oral health and hygiene care. [source]

Thymol and modified atmosphere packaging to control microbiological spoilage in packed fresh cod hamburgers

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2009
Maria Rosaria Corbo
Summary A study on the use of mild technologies to produce packaged fish hamburgers was presented. In particular, the antimicrobial effect of some natural compounds (carvacrol, eugenol, thymol, green tea extract, rosemary extract, grapefruit seed extract and lemon extract), at various concentrations (500,10 000 ppm), was screened in vitro against the main fish spoilage micro-organisms (Shewanella putrefaciens and Photobacterium phosphoreum). Lemon extract and thymol, in combination with modified atmosphere packaging, showed the greatest inhibition activity, therefore, thymol was subsequently used as an ingredient for producing fish hamburgers. Results pointed out that this combination is effective in controlling the growth of microbial species mainly involved in fresh fish spoilage; in particular, it significantly (P < 0.05) reduced the growth rate of bacterial population, performing about 4.8 log CFU g,1 and 6.5 log CFU g,1 reduction of the hydrogen sulphide producing bacteria and psychrotrophic aerobic specific spoilage organisms cell load, respectively, if compared with the control. [source]

Dexamethasone inhibits lipopolysaccharide-induced hydrogen sulphide biosynthesis in intact cells and in an animal model of endotoxic shock

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009
Ling Li
Abstract Dexamethasone (1 mg/kg, i.p.) administered either 1 hr before or 1 hr after E. coli lipopolysaccharide (LPS, 4 mg/kg, i.p.) in conscious rats inhibited the subsequent (4 hrs) rise in plasma cytokine (interleukin [IL]-1,, tumour necrosis factor [TNF]-,), nitrate/nitrite (NO×), soluble intercellular adhesion molecule-1 (sICAM-1) concentration and lung/liver myeloperoxidase activity indicative of an anti-inflammatory effect. Dexamethasone also reduced the LPS-evoked rise in plasma hydrogen sulphide (H2S) concentration, liver H2S synthesizing activity and expression of cystathionine , lyase (CSE) and inducible nitric oxide synthase (iNOS). Mifepristone (RU-486) inhibited these effects. Dexamethasone (1,10 ,M) reduced the LPS-evoked release of IL-1,, TNF-, and L-selectin, decreased expression of CSE and iNOS and diminished nuclear factor ,B (NF-,B)-DNA binding in isolated rat neutrophils. In contrast, NaHS (100 ,M) increased L-selectin release from rat neutrophils. Dexamethasone also reduced LPS-induced up-regulation of CSE in foetal liver cells. 6-amino-4-(4-phenoxyphenylethylamino) quinazoline (QNZ, 10 nM), a selective inhibitor of transcription via the NF-,B pathway, abolished LPS-induced up-regulation of CSE expression. We propose that inhibition of CSE expression and reduction in formation of the pro-inflammatory component of H2S activity contributes to the anti-inflammatory effect of dexamethasone in endotoxic shock. Whether H2S plays a part in the anti-inflammatory effect of this steroid in other forms of inflammation such as arthritis or asthma warrants further study. [source]

H2S-induced pancreatic acinar cell apoptosis is mediated via JNK and p38 MAP kinase

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2008
Sharmila Adhikari
Abstract Treatment of pancreatic acinar cells by hydrogen sulphide has been shown to induce apoptosis. However, a potential role of mitogen-activated protein kinases (MAPKs) in this apoptotic pathway remains unknown. The present study examined the role of MAPKs in H2S-induced apoptosis in mouse pancreatic acinar cells. Pancreatic acinar cells were treated with 10 ,M NaHS (a donor of H2S) for 3 hrs. For the evaluation of the role of MAPKs, PD98059, SP600125 and SB203580 were used as MAPKs inhibitors for ERK1/2, JNK1/2 and p38 MAPK, respectively. We observed activation of ERK1/2, JNK1/2 and p38 when pancreatic acini were exposed to H2S. Moreover, H2S-induced ERK1/2, JNK1/2 and p38 activation were blocked by pre-treatment with their corresponding inhibitor in a dose-dependent manner. H2S-induced apoptosis led to an increase in caspase 3 activity and this activity was attenuated when caspase 3 inhibitor were used. Also, the cleavage of caspase 3 correlated with that of poly-(ADP-ribose)-polymerase (PARP) cleavage. H2S treatment induced the release of cytochrome c, smac from mitochondria into the cytoplasm, translocation of Bax into mitochondria and decreased the protein level of Bcl-2. Inhibition of ERK1/2 using PD98059 caused further enhancement of apoptosis as evidenced by annexin V staining, while SP600125 and SB203580 abrogated H2S-induced apoptosis. Taken together, the data suggest that activation of ERKs promotes cell survival, whereas activation of JNKs and p38 MAP kinase leads to H2S-induced apoptosis. [source]

Effect of the biomass in the modelling and simulation of the biofiltration of hydrogen sulphide: simulation and experimental validation

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2010
Javier Silva
Abstract BACKGROUND: Several models have been developed to simulate the decay of pollutants concentration along the biofilter and to predict its performance. Despite the evidence, it is common that most models ignore the effect of variable biomass along the biofilter. An equation that represents the variable amount of active biomass along the column was included in the modelling of a biotrickling filter; it was obtained by measuring the active biomass at different heights. Validation of the model was carried out using experimental data obtained at different H2S loads. RESULTS: The simulation considering the expression for variable active biomass along the column shows better correlation with experimental results. With the diffusion coefficient that shows the best fit with the experimental results; 1.35 × 10,9 m2 s,1, the value of the Thiele module is 2 × 10,3, indicating that biooxidation of H2S is controlled by mass transfer. CONCLUSIONS: A better correlation between experimental results and model prediction is obtained when the expression for variable active biomass along the column is considered in the modelling. Copyright © 2010 Society of Chemical Industry [source]

Intra- and extra-oral halitosis: finding of a new form of extra-oral blood-borne halitosis caused by dimethyl sulphide

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2007
Albert Tangerman
Abstract Aim: The aim of this study was to unravel the origen and cause of intra-oral and extra-oral halitosis. Material and Methods: We studied 58 patients complaining of halitosis, using gas chromatography of volatile sulphur compounds (VSCs) in mouth and nose breath, organoleptic scoring of mouth and nose breath, Halimeter® readings of mouth air and tongue-coating inspection. Subjects had no precence or history of periodontitis. Result: Of 58 patients, 47 patients had halitosis of oral origin, six had halitosis of extra-oral origin and five had no halitosis (halitophobia). A strong correlation was found between the degree of intra-oral halitosis as measured by organoleptic scoring of mouth breath and the concentration of the VSCs hydrogen sulphide (H2S) and methyl mercaptan (CH3SH) in mouth breath. Taking into account the much larger odour index of CH3SH, it was concluded that CH3SH is the main contributor to intra-oral halitosis. In all six cases of extra-oral halitosis, halitosis was caused by the presence of elevated levels of dimethyl sulphide (CH3SCH3) in mouth and nose breath. Conclusion: Our study provides evidence that the VSC, CH3SH and to a lesser extent H2S are the main contributors to intra-oral halitosis and that CH3SCH3 is the main contributor to extra-oral or blood-borne halitosis, due to a hitherto unknown metabolic disorder. [source]

Nano Si3N4 composites with improved tribological properties

LUBRICATION SCIENCE, Issue 2 2009
Ingrid Schulz
Abstract Nano Si3N4 composites with tailored microstructure were developed using fine ß-Si3N4 powders. Their wear behaviour was investigated. Whereas pure Si3N4 composites showed improved wear behaviour under dry rolling conditions with slip, TiN-reinforced nano Si3N4 composites generate a self-lubricating behaviour under dry sliding conditions. After chemical treatment with hydrogen sulphide, the friction coefficient and wear rate was found to be significantly decreased under dry sliding conditions. Additionally, the new composites possess higher fracture toughness than the pure nano Si3N4 materials. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Sulphide-induced energy deficiency in colonic cells is prevented by glucose but not by butyrate

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2002
S. J. Hulin
Background: In ulcerative colitis, hydrogen sulphide is postulated to impair colonocyte butyrate metabolism, leading to cellular energy deficiency and dysfunction. Aims: To determine the effects of sulphide exposure on butyrate metabolism and adenosine triphosphate levels of HT29 colonic epithelial cancer cells, and to establish whether energy deficiency can be prevented by increased butyrate concentrations or the presence of glucose. Methods: HT29 cells were maintained in medium containing 3 mM butyrate, 5 mM glucose, or both substrates. Oxidation rates were measured by 14CO2 release from 14C-labelled substrates. Cellular adenosine triphosphate was assayed using the luciferin/luciferase chemiluminescent method. The effects of sulphide (0,5 mM) on substrate oxidation and adenosine triphosphate levels and of increasing butyrate concentration (0,30 mM) with sulphide were observed. Results: HT29 cells showed similar energy substrate usage to primary colonocyte cultures. Sulphide exposure inhibited butyrate oxidation and led to a reduction in cellular adenosine triphosphate. This fall was prevented by co-incubation with glucose, but not by increasing concentrations of butyrate. Conclusions: HT29 cells utilize butyrate as an energy substrate and represent a useful in vitro model of the effects of sulphide on colonocytes. Sulphide inhibits butyrate oxidation and leads to demonstrable energy deficiency, prevented by the presence of glucose but not by increased butyrate concentrations. [source]

Adaptation of the antioxidant defence system in hydrothermal-vent mussels (Bathymodiolus azoricus) transplanted between two Mid-Atlantic Ridge sites

MARINE ECOLOGY, Issue 1 2007
Rui Company
Abstract The vent mussel Bathymodiolus azoricus is the dominant member of the Northern Mid-Atlantic Ridge (MAR) hydrothermal megafauna, and lives in an environment characterized by temporal and spatial variations in the levels of heavy metals, methane and hydrogen sulphide, substances which are known to increase reactive oxygen species levels in the tissues of exposed organisms. To evaluate the effects of two contrasting hydrothermal environments on the antioxidant defence system of this vent mussel species, a 2-week transplant experiment was carried out involving mussels collected from the relatively deep (2300 m), and chemical rich, Rainbow vent field. These were transplanted to the shallower (1700 m), and relatively less toxic, Lucky Strike vent field. To achieve this objective, levels of superoxide dismutase, catalase (CAT), total glutathione peroxidase (GPx), selenium-dependent glutathione peroxidase and lipid peroxidation (LPO) were measured in the gills and mantle tissues of resident and transplant mussels before and after the transplant experiment. With the exception of CAT, the gills of the transplanted mussels had significantly higher antioxidant enzyme activity compared with the basal levels in the donor (Rainbow) and recipient (Lucky Strike) populations; whereas the antioxidant enzyme levels in the mantle tissues of the transplants reflected the baseline levels of activity in the native Lucky Strike mussels after 2 weeks. In contrast, LPO levels were significantly higher in both tissue types in the transplants than in either the source or the recipient populations, which suggested a response to hydrostatic pressure change (note, the transplant animals were brought to the surface for transportation between the two vent fields). The fact that the Rainbow mussels survived the transplant experience indicates that B. azoricus has a very robust constitution, which enables it to cope behaviourally, physiologically and genetically with the extreme conditions found in its naturally contaminated deep-sea environment. [source]

Effect of soybean hull supplementation to finishing pigs on the emission of noxious gases from slurry

ANIMAL SCIENCE JOURNAL, Issue 3 2009
Yuan WANG
ABSTRACT Ninety six pigs were assigned on the basis of body weight (BW) to one of four dietary treatments (4 pigs per pen and 6 pens per treatment) and fed for 4 weeks. Four 14.85% CP diets were formulated to contain graded levels of soybean hulls at 0, 5, 10, or 15%, respectively. The results showed that treatments did not affect growth performance. Coefficient of total tract apparent digestibility (CTTAD) for dry matter (DM) and blood urea nitrogen (BUN) concentrations were decreased linearly (P < 0.05) with the addition level of soybean hulls. Slurry ammonia nitrogen (NH3 -N) was not affected with the increased soybean hulls levels, but volatile fatty acids (VFA) were linearly (P < 0.05) increased. Slurry pH and ammonia (NH3) emissions were significantly decreased by the addition of soybean hulls (Linear, P < 0.05). Conversely, slurry hydrogen sulphide (H2S) emissions exhibited an increase with the addition of soybean hulls (Linear, P < 0.10). Our data indicate that soybean hulls inclusion can decrease slurry pH value and NH3 emission without any negative influence on growth performance. [source]

Gase als zelluläre Signalstoffe.

BIOLOGIE IN UNSERER ZEIT (BIUZ), Issue 3 2010
Gasotransmitter
Abstract Die Gase Stickoxid (NO), Kohlenmonoxid (CO) und Schwefelwasserstoff (H2S) werden aufgrund ihrer Wirkung als Signalstoffe als "Gasotransmitter" zusammengefasst. Diese Gase spielen eine wichtige Rolle als intra- und interzellulärer Signalstoff im Verdauungs-, Atmungs- oder Urogenitalsystem, bei der Steuerung des Herzschlags oder Nervenaktivitäten. Die Forschung ist dabei, Funktionen und weitere Details der Wirkmechanismen dieser Gase und ihre Implikationen für Physiologie, Pathophysiologie und Pharmakologie zu erarbeiten. Vom bisher neuesten Kandidaten , dem H2S , gibt es Hinweise, dass er in hoher Konzentration im Gehirn und in den Hoden vorkommt und bei Lern-/Gedächtnisprozessen sowie bei Geschlechtsfunktionen eine Rolle spielt. Durch Entwicklung von Wirksubstanzen zur Beeinflussung der H2S-Produktion oder entsprechender Zielorte könnte sich hieraus ein interessantes pharmakologisches Potenzial entwickeln. Gasotransmitters , gases as cellular signalling molecules The gases nitric oxide (NO), carbon monoxide (CO) and hydrogen sulphide (H2S) because of their capacity as signalling molecules have been now collectively termed "gasotransmitters". These gases play an important role in inter- and intracellular signalling, as in the digestive, respiratory or urogenital tract, in controlling heart activity or in nerve function. Research now tries to work out functions and further details about the mechanism of action of these gases and their implications for physiology, pathophysiology and pharmacology. The most recent candidate, H2S, is found in high concentrations in the brain and in the testis and hence is involved in learning/memory and in reproductive functions. The development of new substances interfering with the production of H2S or its targets may constitute an interesting pharmacological potential. [source]

Potential importance of alterations in hydrogen sulphide (H2S) bioavailability in diabetes

BRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2008
D J Lefer
British Journal of Pharmacology (2008) 155, 1308; doi:10.1038/bjp.2008.377 [source]

Potential importance of alterations in hydrogen sulphide (H2S) bioavailability in diabetes

BRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2008
D J Lefer
Despite its long-standing reputation as a foul smelling and toxic gas that is associated with the decay of biological matter, hydrogen sulphide (H2S) has emerged as an important regulator of cardiovascular homoeostasis. H2S promotes a number of cellular signals that regulate metabolism, cardiac function and cell survival. Endogenous H2S bioavailability is regulated by several enzymes involved in the biosynthesis of cysteine. This study by Brancaleone et al. in the current issue of the British Journal of Pharmacology provides novel insights into the impairment of H2S biosynthesis in the setting of diabetes mellitus. The authors report that enzymic H2S biosynthesis is impaired in a murine model of type 1 diabetes and the attenuation in H2S bioavailability is associated with impaired vascular reactivity. This study has profound implications for the use of pharmacological agents to augment endogenous H2S synthesis or agents that release H2S to augment the levels of this gaseous signalling molecule in cardiovascular disease. British Journal of Pharmacology (2008) 155, 617,619; doi:fn1; published online 22 September 2008 [source]

What is the significance of vascular hydrogen sulphide (H2S)?

BRITISH JOURNAL OF PHARMACOLOGY, Issue 6 2006
S E O'Sullivan
The important role of nitric oxide (NO) in the regulation of vascular tone has been well studied. By contrast, the vascular significance of another gaseous mediator, hydrogen sulphide (H2S), is still poorly understood. A study published in this issue of the British Journal of Pharmacology now provides evidence that in addition to the vasorelaxant effects of H2S reported in vitro, low concentrations of H2S also cause arterial vasoconstriction, reverse NO-mediated vasorelaxation and cause an NO-dependent pressor effect in vivo. This commentary discusses the implications and questions raised by these results. British Journal of Pharmacology (2006) 149, 609,610. doi:10.1038/sj.bjp.0706907 [source]

Role of hydrogen sulphide in haemorrhagic shock in the rat: protective effect of inhibitors of hydrogen sulphide biosynthesis

BRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2004
Ying-Yuan Pamela Mok
Haemorrhagic shock (60 min) in the anaesthetized rat resulted in a prolonged fall in the mean arterial blood pressure (MAP) and heart rate (HR). Pre-treatment (30 min before shock) or post-treatment (60 min after shock) with inhibitors of cystathionine , lyase (CSE; converts cysteine into hydrogen sulphide (H2S)), dl-propargylglycine or , -cyanoalanine (50 mg kg,1, i.v.), or glibenclamide (40 mg kg,1, i.p.), produced a rapid, partial restoration in MAP and HR. Neither saline nor DMSO affected MAP or HR. Plasma H2S concentration was elevated 60 min after blood withdrawal (37.5±1.3 ,m, n=18 c.f. 28.9±1.4 ,m, n=15, P<0.05). The conversion of cysteine to H2S by liver (but not kidney) homogenates prepared from animals killed 60 min after withdrawal of blood was significantly increased (52.1±1.6 c.f. 39.8±4.1 nmol mg protein,1, n=8, P<0.05), as was liver CSE mRNA (2.7 ×). Both PAG (IC50, 55.0±3.2 ,m) and BCA (IC50, 6.5±1.2 ,m) inhibited liver H2S synthesizing activity in vitro. Pre-treatment of animals with PAG or BCA (50 mg kg,1, i.p.) but not glibenclamide (40 mg kg,1, i.p., KATP channel inhibitor) abolished the rise in plasma H2S in animals exposed to 60 min haemorrhagic shock and prevented the augmented biosynthesis of H2S from cysteine in liver. These results demonstrate that H2S plays a role in haemorrhagic shock in the rat. CSE inhibitors may provide a novel approach to the treatment of haemorrhagic shock. British Journal of Pharmacology (2004) 143, 881,889. doi:10.1038/sj.bjp.0706014 [source]