Synthesis of High Purity Lithium Sulfide for Sulfide Solid Electrolyte Applications through Hydrogen Reduction of Lithium Sulfate

This paper is aimed to present a clean,inexpensive and sustainable method to synthesize high purity lithium sulfide(Li_(2)S)powder through hydrogen reduction of lithium sulfate(Li_(2)SO_(4)).A three-step reduction process has been successfully developed to synthesize well-crystallized and single-phase Li_(2)S powder by investigating the melting,sintering and reduction behavior of the mixtures of Li_(2)SO_(4)-Li_(2)S.High purity alumina was found to be the most suitable crucible material for producing high purity Li_(2)S,because it was not attacked by the Li_(2)SO_(4)-Li_(2)S melt during heating,as compared with other materials,such as carbon,mullite,quartz,boron nitride and stainless steel.The use of synthesized LizS resulted in higher purity and substantially higher room temperature ionic conductivity(2.77 mS·cm^(-1))for the argyrodite sulfide electrolyte Li_(6)PS_(5)Cl than commercial Li_(2)S(1.12 mS·cm^(-1)).This novel method offers a great opportunity to produce battery grade Li_(2)S for sulfide solid electrolyte applications.

Hydrogen sulfide reduces oxidative stress in Huntington's disease via Nrf2

The pathophysiology of Huntington's disease involves high levels of the neurotoxin quinolinic acid. Quinolinic acid accumulation results in oxidative stress, which leads to neurotoxicity. However, the molecular and cellular mechanisms by which quinolinic acid contributes to Huntington's disease pathology remain unknown. In this study, we established in vitro and in vivo models of Huntington's disease by administering quinolinic acid to the PC12 neuronal cell line and the striatum of mice, respectively. We observed a decrease in the levels of hydrogen sulfide in both PC12 cells and mouse serum, which was accompanied by down-regulation of cystathionine β-synthase, an enzyme responsible for hydrogen sulfide production. However, treatment with NaHS(a hydrogen sulfide donor) increased hydrogen sulfide levels in the neurons and in mouse serum, as well as cystathionine β-synthase expression in the neurons and the mouse striatum, while also improving oxidative imbalance and mitochondrial dysfunction in PC12 cells and the mouse striatum. These beneficial effects correlated with upregulation of nuclear factor erythroid 2-related factor 2 expression. Finally, treatment with the nuclear factor erythroid 2-related factor 2inhibitor ML385 reversed the beneficial impact of exogenous hydrogen sulfide on quinolinic acid-induced oxidative stress. Taken together, our findings show that hydrogen sulfide reduces oxidative stress in Huntington's disease by activating nuclear factor erythroid 2-related factor 2,suggesting that hydrogen sulfide is a novel neuroprotective drug candidate for treating patients with Huntington's disease.

Comparative study on the hydrogen storage performance of as-milled MgRENi rapid quenched alloy catalyzed by metal sulfides

The composites of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)as-quenched alloy and 3 wt.%M(M=CoS,CoS_(2),MoS_(2))catalyst were prepared by high-speed vibration ball mill.The effects of metal sulfides on the hydrogenation and dehydrogenation dynamics of alloys were compared.The results show that the as-milled composites contain a large number of amorphous embedded by a small amount of nanocrystals,and there are many point defects.After ball milling,the crystal grain size in the composites containing CoS is relatively larger,followed by CoS_(2)and MoS_(2)again.After hydrogenation,the amorphous phase is crystallized to form Mg_(2)NiH_(4),YH_(3),Pr_(8)H_(18.96),Sm_(3)H_7,Mg,Co or Mo phases,however,Mg_(2)Ni,YH_(2),PrH_(2)and Ni_(3)Y phases appeared after dehydrogenation.The maximum hydrogenation capacity of the composites containing CoS,CoS_(2)and MoS_(2)are 3.939,4.265 and 4.507 wt.%,respectively.The hydrogenation saturation ratio of composite containing MoS_(2)is higher than that of the composites containing CoS and CoS_(2).The dehydrogenation activation energy of the composites containing CoS,CoS_(2)and MoS_(2)is 107.76,68.43 and 63.28 kJ.mol^(-1).H_(2).On the improvement of hydrogen storage performance of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)alloy,the catalytic effect of MoS_(2)sulfide is better than that of CoS_(2)sulfide,and which is better than CoS sulfide.

A hypothesis for treating inflammation and oxidative stress with hydrogen sulfide during age-related macular degeneration

Age-related macular degeneration（AMD） is a leading cause of blindness and is becoming a global crisis since affected people will increase to 288 million by 2040.Genetics,age,diabetes,gender,obesity,hypertension,race,hyperopia,iris-color,smoking,sun-light and pyroptosis have varying roles in AMD,but oxidative stress-induced inflammation remains a significant driver of pathobiology.Eye is a unique organ as it contains a remarkable oxygengradient that generates reactive oxygen species（ROS） which upregulates inflammatory pathways.ROS becomes a source of functional and morphological impairments in retinal pigment epithelium（RPE）,endothelial cells and retinal ganglion cells.Reports demonstrated that hydrogen sulfide（H2S） acts as a signaling molecule and that it may treat ailments.Therefore,we propose a novel hypothesis that H2S may restore homeostasis in the eyes thereby reducing damage caused by oxidative injury and inflammation.Since H_2S has been shown to be a powerful antioxidant because of its free-radicals＇ inhibition properties in addition to its beneficial effects in age-relatedconditions,therefore,patients may benefit from H2S salubrious effects not only by minimizing their oxidant and inflammatory injuries to retina but also by lowering retinal glutamate excitotoxicity.

Effect of Exogenous Hydrogen Sulfide(H_2S) on the Electrocardiogram(ECG) of Rats Generally Anaesthetized by Zoletil

Hydrogen sulfide （H2S） is the third gaseous signaling molecule discovered in recent years, and plays an important physiological role in the cardivascular system. To explore the effects of different doses of exogenous H2S on the electrocardiogram （ECG） of rats generally anesthetized by zoletil, different doses of NariS solution were used for the intervention of intraperitoneal injection 20 rain before the zoletil anesthesia. The ECGs of rats from each treatment group during the time range of 10^th-50^th min were determined under general anesthesia, and then were compared with those from the control group. The results showed that exogenous H2S could significantly reduce the Q-T interval time limit, thus played a role in slowing tachycardia or arrhythmia and other anomalies, thereby protecting the heart. S-T segment and T segment evaluation values were significantly reduced, which might be associated with bradycardia.

Hydrogen sulfide responsive nanoplatforms: Novel gas responsive drug delivery carriers for biomedical applications

Hydrogen sulfide(H_(2)S)is a toxic,essential gas used in various biological and physical processes and has been the subject of many targeted studies on its role as a new gas transmitter.These studies have mainly focused on the production and pharmacological side effects caused by H_(2)S.Therefore,effective strategies to remove H_(2)S has become a key research topic.Furthermore,the development of novel nanoplatforms has provided new tools for the targeted removal of H_(2)S.This paper was performed to review the association between H_(2)S anddisease,relatedH_(2)S inhibitory drugs,aswell as H_(2)S responsive nanoplatforms(HRNs).This review first analyzed the role of H_(2)S in multiple tissues and conditions.Second,common drugs used to eliminate H_(2)S,as well as their potential for combination with anticancer agents,were summarized.Not only the existing studies on HRNs,but also the inhibition H_(2)S combined with different therapeutic methods were both sorted out in this review.Furthermore,this review provided in-depth analysis of the potential of HRNs about treatment or detection in detail.Finally,potential challenges of HRNs were proposed.This study demonstrates the excellent potential of HRNs for biomedical applications.

Absorption characteristics,model,and molecular mechanism of hydrogen sulfide in morpholine acetate aqueous solution

The solubility of H_(2)S was measured in solutions of N-butyl-N-methylmorpholine acetate([Bmmorp][Ac])containing 20%-40%(mass)water at experimental temperatures ranged from 298.15 to 328.15 K and pressures up to 320 k Pa.The total solubility of H_(2)S increased with higher temperatures,lower pressures,and reduced water content.The reaction equilibrium thermodynamic model was used to correlate the solubility data.The results indicate that the chemical reaction equilibrium constant decrease with increasing water content and temperature,whereas Henry constant increase with increasing water content and temperature.Compared with other ionic liquids,H_(2)S exhibits a higher physical absorption enthalpy and a lower chemical absorption enthalpy in[Bmmorp][Ac]aqueous solution.This suggests that[Bmmorp][Ac]has a strong physical affinity for H_(2)S and low energy requirement for desorption.Quantum chemical methods were used to investigate the molecular mechanism of H_(2)S absorption in ionic liquids.The interaction energy analysis revealed that the binding of H_(2)S with the ionic liquid in a1:2 ratio is more stable.Detailed analyses by the methods of the interaction region indicator and the atoms in molecules were conducted to the interactions between H_(2)S and the ionic liquid.

Nano-Ni-Induced Electronic Modulation of MoS_(2) Nanosheets Enables Energy-Saving H_(2) Production and Sulfide Degradation

Electrocatalytic hydrogen evolution and sulfion(S^(2-))recycling are promising strategies for boosting H_(2)production and removing environmental pollutants.Here,a nano-Ni-functionalized molybdenum disulfide(MoS_(2))nanosheet was assembled on steel mesh(Ni-MoS_(2)/SM)for use in sulfide oxidation reaction-assisted,energy-saving H_(2)production.Experimental and theoretical calculation results revealed that anchoring nano-Ni on high-surface-area slack MoS_(2)nanosheets not only optimized catalyst adsorption of polysulfides but also played an important role in promoting hydrogen evolution reaction kinetics by absorbing OH_(ad),thereby greatly enhancing the catalytic performance toward sulfide oxidation reaction and hydrogen evolution reaction.Meanwhile,the Ni/MoS^(2-)based hydrogen evolution reaction+sulfide oxidation reaction system achieved nearly 100%hydrogen production efficiency and only consumed 61%less power per kWh than the oxygen evolution reaction+hydrogen evolution reaction system,which suggested our proposed Ni-MoS_(2)and novel hydrogen production system are promising for sustainable energy production.

The Modification of Diphenyl Sulfide to Pd/C Catalyst and Its Application in Selective Hydrogenation of p-Chloronitrobenzene

In this study, diphenyl sulfide(Ph2S) was employed to prepare a series of Ph2S-modified Pd/C catalysts(Pd–Ph2S/C). Catalyst characterization carried out by Brunner–Emmet–Teller(BET), energy dispersive spectrometer(EDS), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and CO chemisorption uptake measurements suggested a chemical interaction between Ph2 S and Pd. The ligand was preferably absorbed on the active site of Pd metal but after increasing the amount of Ph2 S, the adsorption of Ph2 S on Pd metal tended to be saturated and the excess of Ph2 S partially adsorbed on the activated carbon. A part of Pd atoms without adsorbing any Ph2 S still existed, even for the saturated Pd–Ph2S/C catalyst. The Pd–Ph2S/C catalysts exhibited a good selectivity of p-chloroaniline(p-CAN) in the hydrogenation of p-chloronitrobenzene(p-CNB). However,the chemisorption between Ph2 S and Pd was not so strong that part of Ph2 S was leached from Pd–Ph2S/C catalyst during the hydrogenation, which caused the decline of the selectivity of p-CAN over the used Pd–Ph2S/C catalyst.Resulfidation of the used Pd–Ph2S/C catalyst was effective to resume its stability, and the regenerated Pd–Ph2S/C catalyst could be reused for at least ten runs with a stable catalytic performance.

Endogenous hydrogen sulfide and ERK1/2-STAT3 signaling pathway may participate in the association between homocysteine and hypertension

Background Homocysteine(Hcy)is a risk factor for hypertension,although the mechanisms are poorly understood.Methods We first explored the relationship between Hcy levels and blood pressure(BP)by analyzing the clinical data of primary hypertensive patients admitted to our hospital.Secondly,we explored a rat model to study the effect of Hcy on blood pressure and the role of H2S.An hyperhomocysteinemia(HHcy)rat model was induced to explore the effect of Hcy on blood pressure and the possible mechanism.We carried out tissue histology,extraction and examination of RNA and protein.Finally,we conducted cell experiments to determine a likely mechanism through renin-angiotensin-aldosterone system(RAAS)and extracellular signal-regulated kinase 1/2(ERK1/2)signaling pathway.Results In primary hypertensive inpatients with HHcy,blood pressure was significantly higher as compared with inpatient counterparts lacking HHcy.In the rat model,blood pressure of the Wistar rats was significantly increased with increases in serum Hcy levels and decreased after folate treatment.Angiotensin converting enzyme 1(ACE1)expression in the Wistar Hcy group was enhanced comparing to controls,but was decreased in the Wistar folate group.Angiotensin II receptor type 1(AGTR1)levels in the kidney tissue increased in the Wistar folate group.Both serum H2S and kidney cystathionineγ-lyase decreased with elevated levels of serum Hcy.In vitro,increased concentrations and treatment times for Hcy were associated with increased expression of collagen type 1 and AGTR1.This dose and time dependent response was also observed for p-STAT3 and p-ERK1/2 expression.Conclusion Endogenous H2S might mediate the process of altered blood pressure in response to changes in serum Hcy levels,in a process that is partly dependent on activated RAAS and ERK1/2-STAT3 signaling pathway.

Reactions of Group V Metal Atoms with Hydrogen Sulfide： Argon Matrix Infrared Spectra and Theoretical Calculations

The reaction of laser-ablated vanadium, niobium and tantalum atoms with hydrogen sulfide has been investigated using matrix isolation FTIR and theoretical calculations. The metal atoms inserted into the H-S bond of H2S to form the HMSH molecules （M=V, Nb, Ta）, which rearranged to H2MS molecules on annealing for Nb and Ta. The HMSH molecule can also further react with another H2S to form the H2M（SH）2 molecules. These new molecules were identified on the basis of the D2S and H234S isotopic substitutions. DFT （B3LYP and BPW91） theoretical calculations are used to predict energies, geometries, and vibrational frequencies for these novel metal dihydrido complexes and molecules. Reaction mechanism for formation of group V dihydrido complex was investigated by DFT internal reaction coordinate calculations. The dissociation of HVSH gave VS＋H2 on broad band irradiation and reverse reaction happened on annealing. Based on B3LYP calculation releasing hydrogen from HVSH is endothermic only by 13.5 kcal/mol with lower energy barrier of 16.9 kcal/mol.

Studies on the Tolerating Mechanism for Sulfide in Urechis unicinctus (Echiura: Urechidae) ──Cytological Observation on Urechis unicinctus in Different Hydrogen Sulfide Environment

This study on the cytological changes of the body wall,aspiratory intestine and crissal bursa in Urechis unicinctus by light microscope (LM) and transmission electron microscope (TEM) showed that the difference between the body wall and the natural environment rich in H 2S was not obvious; that the wall color of the aspiratory intestine in H 2S rich environment changed from normal semitransparency to dark brown; that its epithelia were disassembled and the electron density of its cytoplasm matrix was lower; and that in H 2S rich environment many basophilic granules occurred in the epithelia of the crissal bursa. Granules with single membrane and myelinefingure were found with TEM.

Synthesis of 3D Hexagram-Like Cobalt–Manganese Sulfides Nanosheets Grown on Nickel Foam: A Bifunctional Electrocatalyst for Overall Water Splitting

The exploration of low-cost and efficient bifunctional electrocatalysts for oxygen evolution reaction and hydrogen evolution reaction through tuning the chemical composition is strongly required for sustainable resources. Herein, we developed a bimetallic cobalt–manganese sulfide supported on Ni foam(CMS/Ni) via a solvothermal method. It has discovered that after combining with the pure Co_9S_8 and Mn S, the morphologies of CMS/Ni have modulated. The obtained three-dimensionally hexagram-like CMS/Ni nanosheets have a significant increase in electrochemical active surface area and charge transport ability. More than that, the synergetic effect of Co and Mn has also presented in this composite. Benefiting from these, the CMS/Ni electrode shows great performance toward hydrogen evolution reaction and oxygen evolution reaction in basic medium, comparing favorably to that ofthe pure Co_9S_8/Ni and Mn S/Ni. More importantly, this versatile CMS/Ni can catalyze the water splitting in a twoelectrode system at a potential of 1.47 V, and this electrolyzer can be efficiently driven by a 1.50 V commercial dry battery.

Facile In Situ Fabrication of Nanostructured Graphene–CuO Hybrid with Hydrogen Sulfide Removal Capacity

A simple and scalable synthetic approach for one-step synthesis of graphene–Cu O(TRGC) nanocomposite by an in situ thermo-annealing method has been developed.Using graphene oxide(GO) and copper hydroxide as a precursors reagent,the reduction of GO and the uniform deposition of in situ formed Cu O nanoparticles on graphene was simultaneously achieved.The method employed no solvents,toxic-reducing agents,or organic modifiers.The resulting nanostructured hybrid exhibited improved H2 S sorption capacity of 1.5 mmol H2S/g-sorbent(3 g S/100 g-sorbent).Due to its highly dispersed sub-20 nm Cu O nanoparticles and large specific surface area,TRGC nanocomposite exhibits tremendous potential for energy and environment applications.

Therapeutic importance of hydrogen sulfide in age-associated neurodegenerative diseases

Hydrogen sulfide(H2S)is a gasotransmitter that acts as an antioxidant and exhibits a wide variety of cytoprotective and physiological functions in age-associated diseases.One of the major causes of age-related diseases is oxidative stress.In recent years,the importance of H2S has become clear,although its antioxidant function has not yet been fully explored.The enzymes cystathionineβ-synthase,cystathionineγ-lya-se,and 3-mercaptopyruvate sulfurtransferase are involved in the enzymatic production of H2S.Previously,H2S was considered a neuromodulator,given its role in long-term hippocampal potentiation,but it is now also recognized as an antioxidant in age-related neurodegeneration.Due to aerobic metabolism,the central nervous system is vulnerable to oxidative stress in brain aging,resulting in age-associated degenerative diseases.H2S exerts its antioxidant effect by limiting free radical reactions through the activation of antioxidant enzymes,including superoxide dismutase,catalase,and glutathione peroxidase,which protect against the effects of aging by regulating apoptosis-related genes,including p53,Bax,and Bcl-2.This review explores the implications and mechanisms of H2S as an antioxidant in age-associated neurodegenerative diseases,including Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and Down syndrome.

Bile-acid-activated farnesoid X receptor regulates hydrogen sulfide production and hepatic microcirculation

AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfi de (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5'-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension.

Oil-soluble Ni-Mo sulfide nanoparticles and their hydrogenation catalytic properties

Oil-soluble bimetallic Ni-Mo sulfide nanoparticles（NiMoS） with narrow size distribution were successfully synthesized through a composite-surfactants-assisted-solvothermal process.The surface functionality and lipophilicity of the Ni-Mo sulfides were shown by transmission electronic microscopy,Fourier transform infrared and ultraviolet spectroscopy.The as-prepared Ni-Mo sulfides supported on activated carbon（NiMoS/AC） exhibited enhanced catalytic activity towards naphthalene hydrogenation instead of cracking.For comparison,CoMoS/AC and MoS2/AC catalysts were also prepared through similar procedures,and it was found that their catalytic performance decreased in the order of NiMoS/AC〉CoMoS/AC〉MoS2/AC.Furthermore,the activity of the bimetallic NiMoS nanocatalyst can be effectively tuned via variation of the atomic ratio of Ni/（Ni＋Mo）.

Hydrogen sulfide intervention in focal cerebral ischemia/reperfusion injury in rats

The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.

Regulatory effects of hydrogen sulfide on alveolar epithelial cell endoplasmic reticulum stress in rats with acute lung injury

BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic acid(OA).METHODS: Seventy-two male Sprague Dawley(SD) rats were divided into control group, oleic acid-induced ALI group(OA group), oleic acid-induced ALI with sodium hydrosulfide(Na HS) pretreatment group(OA+Na HS group), and sodium hydrosulfide treatment group(Na HS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury(IQA), wet/dry weight ratio(W/D) and H2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78(GRP78) and α-subunit of eukaryotic translation initiation factor-2(el F2α) in lung tissues were measured by immunohistochemical staining and Western blotting.RESULTS: The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and Na HS. The level of H2 S in lung tissue at the three time points significantly decreased in rats injected with OA, but significantly increased in other rats injected with both OA and Na HS. GRP78 and el F2α decreased in rats injected with OA, but increased in other rats injected with both OA and Na HS, especially at 4-hour and 6-hour time points.CONCLUSION: The results suggested that H2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.

Hydrogen sulfide system in the pathogenesis of renovascular hypertension in rats

Objective To investigate the role of hydrogen sulfide(H_(2)S)synthases/H_(2)S pathway in the pathogenesis of renovascular hypertension.Methods Wistar rats were subdivided into 4 groups:(1)2-kidney,1-clip(2K-1C group,n=7),(2)control(n=7),(3)sham(n=7),and(4)2K-1C plus sodium hydrosulfide(NaHS)(NaHS-treated group,n=7).The systolic blood pressure(SBP)was measured by a tail-cuff method using a pulse transducer once a week.Four weeks later,all rats were killed and the concentration of plasma hydrogen sulfide(H_(2)S),the activity of the H_(2)S synthases in the kidneys on both sides,the plasma angiotensinⅡconcentration,and the left-to-whole heart weight ratio were measured.Results The SBP was significantly increased in the 2K-1C group(185.4±14.0mmHg)comparing with those in the sham group(112.9±6.5mmHg,,or the NaHS-treated group(134.8±9.5mmHg))(both P<0.01).At 4 weeks,the angiotensinⅡconcentration in the plasma was increased in the 2K-1C and NaHS-treated group,comparing with the control and the sham group(306.92±7.03 pg/ml and 240.73±13.22 pg/ml vs 122.6±25.49 pg/ml and 125.95±10.55 pg/ml,respectively,both P<0.05).The plasma H_(2)S concentration and the activity of H_(2)S synthases in the left kidney were decreased in the 2K-1C group comparing with those in the sham and the control groups.There was no difference of the activity of the H_(2)S synthases in the right kidneys among the 4 groups.The left-to-whole heart weight ratio was increased in the 2K-1C and the NaHS-treated group camparing with that in the sham and natural control groups.Conclusions Dysfunction of the H_(2)S synthases/H_(2)S pathway was involved in the 2K-1C-induced renovascular hypertension in rat.Exogenous administration of H_(2)S donor can attenuate the development of hypertension.These findings suggest that the H_(2)S synthases/H_(2)S pathway participates in the pathogenesis of renovascular hypertension.