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1.
Plant Physiol Biochem ; 162: 752-761, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33799186

RESUMO

In this study, the role of nitric oxide (NO) burst in modulating Si-induced defensive responses in leaves and roots of Salvia officinalis under copper (Cu) stress were investigated. The result showed that 400 µM Cu markedly reduced shoot dry weight, but increased electrolyte leakage (EL) in leaves and both Si and sodium nitroprusside (SNP as the NO donor) improved these attributes in a dose-dependent manner. Interestingly, Cu toxicity systemically boosted a NO burst in both roots and shoots and applying Si and SNP markedly intensified it. The application of Si and SNP alone as well as their combination improved growth parameters and systemically alleviated Cu-induced lipid peroxidation and H2O2 accumulation through lowering Cu accumulation, increasing proline content, enhancing the activities of catalase (CAT) and superoxide dismutase (SOD) in both roots and leaves and up-regulating expression of SOD gene in leaves of S. officinalis. NO generation was substantially arrested and the responses induced by Si were significantly suppressed by pretreatment with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy l-3-oxide (cPTIO) as a NO scavenger, Nx-Nitro- L-arginine methyl ester hydrochloride (L-NAME) as a nitric oxide synthase inhibitor, and tungstate as a nitrate reductase inhibitor. These novel results indicate that Si can induce Cu tolerance through triggering NO generation which systemically modulates defensive reactions in both roots and leaves of Salvia officinalis.


Assuntos
Óxido Nítrico , Salvia officinalis , Antioxidantes , Cobre/toxicidade , Peróxido de Hidrogênio , Nitroprussiato/farmacologia , Raízes de Plantas , Silício
2.
Plant Physiol Biochem ; 160: 329-340, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33548800

RESUMO

AIM: Water-deficit stress is the most devastating environmental factor that adversely affects plant growth causing yield losses and low crop productivity. In this study, we employed sodium nitroprusside (SNP) as a seed priming agent for the acclimation of water-deficit stress in wheat plants by invoking priming memory. METHODS: The SNP-primed (75, 100, and 125 µM) and non-primed controls were allowed to grow in pots under water deficit and normal conditions. The flag leaves of 98-days mature plants were used for biochemical and physiological studies by following the well-established methods. RESULTS: The antioxidant and hydrolytic enzymes were upregulated while reducing sugars, total sugars, and glycine betaine increased significantly in flag leaves of wheat plants originated from SNP-treated seeds compared to control under water deficit stress. However, a significant reduction in MDA and proline contents represented a lesser ROS production which resulted in enhanced cell membrane stability. Consequently, there was a significant enhancement in yield, plant biomass and 100 grains weight of wheat plants under water deficit stress. CONCLUSION: The improvement in yield parameters indicates the induction of priming memory in SNP-primed seeds which elicit water deficit tolerance till the maturity of plants thus ensures sustainable productivity of wheat.


Assuntos
Aclimatação , Secas , Nitroprussiato/farmacologia , Triticum/efeitos dos fármacos , Triticum/fisiologia , Água/fisiologia
3.
Food Chem ; 346: 128934, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33418413

RESUMO

Quality loss in pear fruit during storage reduces its marketability for long run. To increase its storability, the efficacy of postharvest dip treatment donor sodium nitroprusside (SNP) 0.000, 0.001, 0.002 and 0.003 mol L-1 were investigated on pear fruit cv. Patharnakh under storage conditions (low temperature 0-1 °C and relative humidity (90-95%). SNP effectively lowered fruit mass loss, retained colour and higher firmness, suppressed browning and respiration rate and sustained soluble solids content, titratable acidity, total phenol content and ascorbic acid thus conserved the fruit quality for longer period. SNP treatments suppressed the activity of polyphenol oxidase and increased activity of superoxide dismutase enzyme. Additionally, the SNP treated fruit exhibited lesser activities of fruit softening enzymes like pectin methylesterase, polygalacturonase and cellulase. Among all, 0.002 mol L-1 SNP concentration was superior to lengthen storability and sensory quality of pear up to 60 d under cold storage.


Assuntos
Fenômenos Químicos/efeitos dos fármacos , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Frutas/química , Nitroprussiato/farmacologia , Pyrus/efeitos dos fármacos , Frutas/efeitos dos fármacos , Pyrus/química , Pyrus/enzimologia
4.
Chemosphere ; 262: 128384, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182105

RESUMO

Arsenic (As) polluted food chain has become a serious issue for the growth and development of humans, animals and plants. Nitric oxide (NO) or silicon (Si) may mitigate As toxicity. However, the combined application of NO and Si in mitigating As uptake and phytotoxicity in Brassica juncea is unknown. Hence, the collegial effect of sodium nitroprusside (SNP), a NO donor and Si application on B. juncea growth, gas exchange parameters, antioxidant system and As uptake was examined in a greenhouse experiment. Arsenic toxicity injured cell membrane as signposted by the elevated level of malondialdehyde (MDA) and hydrogen peroxide (H2O2), thus decreasing the growth of stressed plants. Moreover, As stress negatively affected gas exchange parameters and antioxidative system of plants. However, NO or/and Si alleviated As induced oxidative stress through increasing the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), along with thiol and proline synthesis. Furthermore, plants treated with co-application of NO and Si showed improved growth, gas attributes and decreased As uptake under As regimes. The current study highlights that NO and Si synergistically interact to mitigate detrimental effects of As stress through reducing As uptake. Our findings recommend combined NO and Si application in As spiked soils for improvement of plant growth and stress alleviation.


Assuntos
Arsênico/metabolismo , Mostardeira/fisiologia , Óxido Nítrico/química , Silício/química , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Arsênico/toxicidade , Ascorbato Peroxidases/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Mostardeira/metabolismo , Doadores de Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Superóxido Dismutase/metabolismo
5.
J Agric Food Chem ; 68(52): 15460-15467, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33320657

RESUMO

The anthracnose rot of postharvest mango fruit is a devastating fungal disease often resulting in tremendous quality deterioration and postharvest losses. Nitric oxide (NO), as an important signaling molecule, is involved in the responses to postharvest fruit diseases. In the present study, the effectiveness of NO donor sodium nitroprusside (SNP) to prevent anthracnose of "Tainong" mango fruit caused by Colletotrichum gloeosporioides was evaluated through in vivo and in vitro tests. Results from in vivo test showed that SNP treatment effectively inhibited the lesion diameter and disease incidence on inoculated mango fruit during storage. SNP treatment could regulate hydrogen peroxide levels by reinforcing the activities of catalase, peroxidase, superoxide dismutase, and ascorbate peroxidase. Furthermore, SNP elevated the accumulation of lignin, total phenolics, anthocyanin, and flavonoids and the activities of chitinase and ß-1,3-glucanase. In addition, in vitro tests indicated that SNP markedly suppressed mycelial growth and spore germination of C. gloeosporioides through damaging plasma membrane integrity and increasing the leakage of soluble sugar and protein. Our results suggested that SNP could suppress anthracnose decay in postharvest mango fruit, possibly by directly suppressing pathogen growth and indirectly triggering host defense responses.


Assuntos
Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Frutas/efeitos dos fármacos , Mangifera/microbiologia , Nitroprussiato/farmacologia , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Conservação de Alimentos/instrumentação , Frutas/microbiologia , Fungicidas Industriais/farmacologia , Mangifera/efeitos dos fármacos , Óxido Nítrico/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
6.
Pediatr Cardiol ; 41(7): 1301-1318, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32915293

RESUMO

Alterations in blood pressure are common during the perioperative period in infants and children. Perioperative hypertension may be the result of renal failure, volume overload, or activation of the sympathetic nervous system. Concerns regarding end-organ effects or postoperative bleeding may mandate regulation of blood pressure. During the perioperative period, various pharmacologic agents have been used for blood pressure control including sodium nitroprusside, nitroglycerin, ß-adrenergic antagonists, fenoldopam, and calcium channel antagonists. The following manuscript outlines the commonly used pharmacologic agents for perioperative BP including dosing regimens and adverse effect profiles. Previously published clinical trials are discussed and efficacy in the perioperative period reviewed.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Adolescente , Antagonistas Adrenérgicos beta/efeitos adversos , Antagonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/uso terapêutico , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/farmacologia , Bloqueadores dos Canais de Cálcio/efeitos adversos , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Criança , Pré-Escolar , Fenoldopam/efeitos adversos , Fenoldopam/farmacologia , Fenoldopam/uso terapêutico , Humanos , Hipertensão/etiologia , Lactente , Masculino , Nitroprussiato/efeitos adversos , Nitroprussiato/farmacologia , Nitroprussiato/uso terapêutico , Período Perioperatório , Insuficiência Renal/complicações , Resultado do Tratamento
7.
Chemosphere ; 259: 127356, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650176

RESUMO

Growth of the most important nitrogen fixing cyanobacterium Nostoc muscorum is reported to be badly affected by the application of insecticides. To overcome their damaging effects, several strategies are being used. Out of these, some works on kinetin (KN, a synthetic cytokinin) has been recognized that it can overcome toxicity of insecticides in cyanobacteria. Besides this, it is now known that every hormone needs certain second messengers such as nitric oxide (NO) for its action. But implication of NO in KN-mediated regulation of insecticide toxicity is yet to be investigated. Hence in the current study, we have investigated the possible involvement of NO in KN-mediated regulation of cypermethrin toxicity in the cyanobacterium Nostoc muscorum. Cypermethrin decreased growth of Nostoc muscorum which was accompanied by decreased pigment contents and altered photosystem II (PS II) photochemistry that resulted in inhibition of photosynthetic process but KN significantly ameliorated cypermethrin toxicity. Cypermethrin induced production of free radicals (in-vivo and in-vitro) and weakened defensive mechanism (enzymatic and non-enzymatic defense system) which was restored by KN. Further, the results revealed that NG-nitro-l-arginine methyl ester (l-NAME, an inhibitor of nitric oxide synthase) worsened the effect of cypermethrin toxicity even in the presence of KN while 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO, a scavenger of NO) reversed KN-mediated amelioration even in the presence of sodium nitroprusside (SNP, an NO donor), suggesting that endogenous NO is required for mitigation of cypermethrin toxicity. Overall, our results first time show that endogenous NO is essential for KN-mediated mitigation of cypermethrin toxicity in the Nostoc muscorum.


Assuntos
Citocininas/farmacologia , Nostoc muscorum/fisiologia , Reguladores de Crescimento de Planta/farmacologia , Polissacarídeos Bacterianos/metabolismo , Piretrinas/toxicidade , Cianobactérias/metabolismo , Homeostase/efeitos dos fármacos , Inseticidas/farmacologia , Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Nostoc muscorum/efeitos dos fármacos , Nostoc muscorum/metabolismo , Fotoquímica , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Espécies Reativas de Oxigênio/farmacologia
8.
Sci Rep ; 10(1): 6900, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327685

RESUMO

In this study, Ca2+ mediated NO signalling was studied in response to metalloid (As) stress in Brassica seedlings. Arsenic toxicity strongly suppressed the growth (fresh weight, root and shoot length), photosynthetic pigments, Chl a fluorescence indices (Kinetic traits: Fv, Fm, Fv/Fo, Fm/Fo, ФPo or Fv/Fm, Ψo, ФEo, PIABS, Area and N and redox status (AsA/DHA and GSH/GSSG ratios) of the cell; whereas energy flux traits: ABS/RC, TRo/RC, ETo/RC and DIo/RC along with Fo, Fo/Fv, Fo/Fm, ФDo and Sm) were enhanced. Further, addition of EGTA (Ca2+ scavenger) and LaCl3 (plasma membrane Ca2+ channel blocker) to As + Ca; while c‒PTIO (NO scavenger) and L‒NAME (NO synthase inhibitor) to As + SNP treated seedlings, siezed recovery on above parameters caused due to Ca2+ and NO supplementation, respectively to As stressed seedlings thereby indicating their signalling behaviour. Further, to investigate the link between Ca2+ and NO, when c‒PTIO and L‒NAME individually as well as in combination were supplemented to As + Ca treated seedlings; a sharp inhibition in above mentioned traits was observed even in presence of Ca2+, thereby signifying that NO plays crucial role in Ca2+ mediated signalling. In addition, As accumulation, ROS and their indices, antioxidant system, NO accumulation and thiol compounds were also studied that showed varied results.


Assuntos
Arsênico/toxicidade , Cálcio/metabolismo , Mostardeira/crescimento & desenvolvimento , Óxido Nítrico/metabolismo , Plântula/crescimento & desenvolvimento , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Eletrólitos/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Mostardeira/efeitos dos fármacos , Nitroprussiato/farmacologia , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Plântula/efeitos dos fármacos , Compostos de Sulfidrila/metabolismo , Superóxidos/metabolismo
9.
Am J Physiol Heart Circ Physiol ; 318(4): H925-H936, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32142378

RESUMO

Using high-fidelity micromanometers and flow velocity sensors at right heart catheterization, we compared pulmonary hemodynamics and wave reflections in age-matched normal adults and those with atrial septal defects, separated into three subgroups based on levels of mean pulmonary artery pressure: low (<17 mmHg), intermediate (17-26 mmHg), high (>26 mmHg). We made baseline measurements in all groups and after intravenous sodium nitroprusside in the subgroups. All of the subgroups had higher than normal baseline pulmonary flows and corresponding power that did not differ among the subgroups. The pulmonary vascular resistance, input resistance, and characteristic impedance in the subgroups did not differ from normal. Aside from the elevated flow and power, the hemodynamics in the low subgroup did not differ from normal. The intermediate subgroup had significantly higher than normal right ventricular and pulmonary artery pressures, wave reflections, and shorter wave reflection time, which all reverted to normal after nitroprusside. The high subgroup had similar changes as the intermediate subgroup. Unlike that subgroup, however, the pressures, wave reflections, and reflection return time did not revert to normal after nitroprusside. Hence, elevated wave reflections, but not resistance or characteristic impedance, are the hallmark of pulmonary hypertension in adults with atrial septal defects. Our results demonstrate that detailed measurements of hemodynamics and assessment of responsiveness to vasodilators provide important information about the pulmonary circulation in atrial septal defect. Coupled with studies after defect closure, those results may be a better foundation than current ones for clinical decisions.


Assuntos
Comunicação Interatrial/fisiopatologia , Hemodinâmica , Circulação Pulmonar , Adulto , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Nitroprussiato/farmacologia , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/fisiopatologia , Vasodilatadores/farmacologia
10.
Biochem Biophys Res Commun ; 525(3): 626-632, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32122653

RESUMO

BACKGROUND: When proliferating tumor cells expand to areas distant from vascular sites, poor diffusion of oxygen and nutrients occur, generating a restrictive hypoxic gradient in which susceptible tumor cells die. The heterogeneous population surviving hypoxia and metabolic starvation include de-differentiated cancer stem cells (CSC), capable of self-renewing tumor-initiating cells (TICs), or those that divide asymmetrically to produce non-tumor-initiating differentiated (NTI-D) cell progeny. Under such restrictive conditions, both populations slowly proliferate, entering quiescence or senescence, when exiting from cell cycle progression. This may drive chemoresistance and tumor recurrence, since most anti-cancer treatments target rapidly proliferating cells. PURPOSE: Since persistent or additional stress may increase NTI-D cells conversion to TICs, we investigated whether nutrient depletion or hypoxia influence expression of tyrosinase, a crucial enzyme for melanin synthesis, and B16 melanoma survival, when exposed to iron-dependent cell death oxidative stress produced by the Fenton reaction, resembling ferroptosis. RESULTS: -a) proliferating B16 melanoma with 10% serum-supplementation (10%S) normoxically express hypoxia inducible factor 1α (HIF1α) but lose tyrosinase, in contrast to those transiently exposed to (SF) serum-free medium, in which both HIF1α and tyrosinase are co-expressed; b) in contrast to the resistance to SNP toxicity in (SF) cells with higher tyrosinase expression, those in (10%S) are killed by iron from nitroprusside/ferricyanide (SNP) irrespective of exogenous H2O2, in a reaction antagonized by the anti-oxidant and MEK inhibitor UO126; c) Moreover, under transient serum depletion, SNP cooperates with hypoxia (1.5% oxygen), prolonging B16 melanoma (SF) survival; d) the hypoxia mimetic CoCl2 inhibits proliferation-associated cyclin A, irrespective of SNP, in (10%S) cells or in transiently serum-depleted (SF) cells. However, only in the latter cells, CoCl2 but not SNP, induce loss of HIF1α and apoptosis-associated PARP cleavage; e) longer term adaptation to survive serum depletion, generates (SS) cells resistant to SNP toxicity, which aerobically co-express HIF1α and tyrosinase. In SS B16 melanoma, exogenous non-toxic 100 µM H2O2 super-induces the ratio of tyrosinase to HIF1α. However, co-treatment of SS-B16 cells with SNP plus exogenous H2O2, partly increases PARP cleavage by reciprocally decreasing tyrosinase expression. SIGNIFICANCE: - These results suggest that a phenotypic plasticity in response to depletion of nutrients and/or oxygen, helps decide whether melanoma cells undergo either death by ferroptosis, or resistance to it, when challenged by the same exogenous oxidative stress (iron ± H2O2).


Assuntos
Ferroptose/efeitos dos fármacos , Melanoma Experimental/patologia , Nitroprussiato/farmacologia , Soro/metabolismo , Animais , Butadienos/farmacologia , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cobalto/farmacologia , Meios de Cultura Livres de Soro , Ciclina A/metabolismo , Peróxido de Hidrogênio/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Nitrilos/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Transferrina/deficiência , Transferrina/metabolismo
11.
Am J Physiol Heart Circ Physiol ; 318(4): H937-H946, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32142360

RESUMO

The arterial baroreflex has dominant control over multiunit muscle sympathetic nerve activity (MSNA) burst occurrence, but whether this extends to all single units or is influenced by resting blood pressure status is unclear. In 22 men (32 ± 8 yr), we assessed 68 MSNA single units during sequential bolus injections of nitroprusside and phenylephrine (modified Oxford). Sympathetic baroreflex sensitivity (sBRS) was quantified as the weighted negative linear regression slope between diastolic blood pressure (DBP) and single-unit spike firing probability and multiple spike firing. Strong negative linear relationships (r ≥ -0.50) between DBP and spike firing probability were observed in 63/68 (93%) single units (-2.27 ± 1.27%·cardiac cycle-1·mmHg-1 [operating range, 18 ± 8 mmHg]). In contrast, only 45/68 (66%) single units had strong DBP-multiple spike firing relationships (-0.13 ± 0.18 spikes·cardiac cycle-1·mmHg-1 [operating range, 14 ± 7 mmHg]). Participants with higher resting DBP (65 ± 3 vs. 77 ± 3 mmHg, P < 0.001) had similar spike firing probability sBRS (low vs. high, -2.08 ± 1.08 vs. -2.46 ± 1.42%·cardiac cycle-1·mmHg-1, P = 0.33), but a smaller sBRS operating range (20 ± 6 vs. 16 ± 9 mmHg, P = 0.01; 86 ± 24 vs. 52 ± 25% of total range, P < 0.001) and a higher proportion of single units without arterial baroreflex control outside this range [6/31 (19%) vs. 21/32 (66%), P < 0.001]. Participants with higher resting DBP also had fewer single units with arterial baroreflex control of multiple spike firing (79 vs. 53%, P = 0.04). The majority of MSNA single units demonstrate strong arterial baroreflex control over spike firing probability during pharmacological manipulation of blood pressure. Changes in single-unit sBRS operating range and control of multiple spike firing may represent altered sympathetic recruitment patterns associated with the early development of hypertension.NEW & NOTEWORTHY Muscle sympathetic single units can be differentially controlled during stress. In contrast, we demonstrate that 93% of single units maintain strong arterial baroreflex control during pharmacological manipulation of blood pressure. Interestingly, the operating range and proportion of single units that lose arterial baroreflex control outside of this range are influenced by resting blood pressure levels. Altered single unit, but not multiunit, arterial baroreflex control may represent changes in sympathetic recruitment patterns in early stage development of hypertension.


Assuntos
Artérias/fisiologia , Barorreflexo , Pressão Sanguínea , Músculo Liso Vascular/fisiologia , Sistema Nervoso Simpático/fisiologia , Adulto , Artérias/efeitos dos fármacos , Humanos , Masculino , Condução Nervosa , Nitroprussiato/farmacologia , Fenilefrina/farmacologia , Vasodilatadores/farmacologia
12.
Life Sci ; 250: 117586, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32222464

RESUMO

AIM: The inward rectifier K+ (Kir) channels and prostanoids are important factors in regulating vascular tone, but the relationship between them has not been well studied. We aimed to study the involvement of prostanoids in regulating Kir activity in the rat intrarenal arteries (RIRAs). MAIN METHODS: The vascular tone of isolated RIRAs was recorded with a wire myograph. The intracellular Ca2+ concentrations ([Ca2+]i) and Kir currents were measured with a Ca2+-sensitive fluorescence probe and patch clamp, respectively, in the arterial smooth muscle cell (ASMC) freshly isolated from RIRAs. Kir2.1 expression in RIRAs was assayed by Western blotting. KEY FINDINGS: At 0.03-1.0 mM, BaCl2 (a specific Kir blocker) concentration-dependently contracted RIRAs and elevated [Ca2+]i levels. Mild stimulations with various vasoconstrictors at low concentrations significantly potentiated RIRA contraction induced by Kir closure with BaCl2. In both the quiescent and the stimulated RIRAs, cyclooxygenase inhibition and thromboxane-prostanoid receptor (TPR) antagonism depressed BaCl2-induced RIRA contraction, while nitric oxide (NO) synthetase inhibition and endothelium-denudation enhanced the contraction. Kir2.1 expression was significantly more abundant in smaller RIRAs. Ba2+-sensitive Kir currents were depressed by TPR agonist U46619 while increased by NO donor sodium nitroprusside. SIGNIFICANCE: The present results reveal that vasoconstrictor stimulation augments RIRA contraction induced by Kir closure with Ba+ and indicate that prostanoid synthesis followed by TPR activation is involved in the modulation of the myocyte Kir activity. This study suggests that prostanoid synthesis and TPR may be potential targets for dysfunctions in renal blood circulation.


Assuntos
Miócitos de Músculo Liso/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Prostaglandinas/metabolismo , Artéria Renal/citologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Animais , Artérias/metabolismo , Cálcio/metabolismo , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica , Rim/irrigação sanguínea , Masculino , Óxido Nítrico/metabolismo , Nitroprussiato/farmacologia , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Receptores de Prostaglandina/metabolismo , Tromboxanos/metabolismo , Vasoconstritores/farmacologia
13.
Mol Med Rep ; 21(2): 540-548, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31974599

RESUMO

Placental oxidative stress is present throughout the duration of pregnancy, but it is when oxidative stress exceeds the normal physiological level that complications can occur. Trophoblast cell lines are commonly utilized for oxidative stress research due to their distinct uniform cell population and easy­to­apply interventions. However, conflicting results are often reported when different oxidative stress cell models are used. In this study, the aim was to characterize the intracellular and extracellular metabolite profiles of different oxidative stress cell models commonly used in the research of pregnancy complications. HTR8/SVneo human trophoblast cell lines were treated with five different oxidative stress­inducing conditions: Hypoxia (1% oxygen); hypoxia and reoxygenation; cobalt chloride (CoCl2; 300 µmol/l); sodium nitroprusside (SNP; 2.5 mmol/l); and the serum of women with preeclampsia (10% v/v). Intracellular metabolites were extracted from cells and extracellular metabolites were collected from spent media for metabolomic analysis via gas chromatography­mass spectrometry. The results demonstrated that there were distinct differences in the intracellular and extracellular metabolome between the different cell models. Meanwhile, treatments with exogenous drugs, such as CoCl2 and SNP, resulted in more similar metabolite profiles. These disparities between the different oxidative stress cell models will have implications for the applications of these results, and highlight the need for the standardization of oxidative stress cell models in obstetric research.


Assuntos
Metabolismo , Estresse Oxidativo , Adulto , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cobalto/farmacologia , Humanos , Metabolismo/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Metabolômica , Modelos Biológicos , Nitroprussiato/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Análise de Componente Principal
14.
Diabetes ; 69(3): 424-435, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31806622

RESUMO

Central to the development of diabetic macro- and microvascular disease is endothelial dysfunction, which appears well before any clinical sign but, importantly, is potentially reversible. We previously demonstrated that hyperglycemia activates nuclear factor of activated T cells (NFAT) in conduit and medium-sized resistance arteries and that NFAT blockade abolishes diabetes-driven aggravation of atherosclerosis. In this study, we test whether NFAT plays a role in the development of endothelial dysfunction in diabetes. NFAT-dependent transcriptional activity was elevated in skin microvessels of diabetic Akita (Ins2 +/- ) mice when compared with nondiabetic littermates. Treatment of diabetic mice with the NFAT blocker A-285222 reduced NFATc3 nuclear accumulation and NFAT-luciferase transcriptional activity in skin microvessels, resulting in improved microvascular function, as assessed by laser Doppler imaging and iontophoresis of acetylcholine and localized heating. This improvement was abolished by pretreatment with the nitric oxide (NO) synthase inhibitor l-N G-nitro-l-arginine methyl ester, while iontophoresis of the NO donor sodium nitroprusside eliminated the observed differences. A-285222 treatment enhanced dermis endothelial NO synthase expression and plasma NO levels of diabetic mice. It also prevented induction of inflammatory cytokines interleukin-6 and osteopontin, lowered plasma endothelin-1 and blood pressure, and improved mouse survival without affecting blood glucose. In vivo inhibition of NFAT may represent a novel therapeutic modality to preserve endothelial function in diabetes.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Microvasos/efeitos dos fármacos , Fatores de Transcrição NFATC/antagonistas & inibidores , Pirazóis/farmacologia , Acetilcolina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Endotelina-1/efeitos dos fármacos , Endotelina-1/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Inibidores Enzimáticos/farmacologia , Insulina/genética , Interleucina-6/metabolismo , Iontoforese , Camundongos , Microvasos/metabolismo , Microvasos/fisiopatologia , Fatores de Transcrição NFATC/efeitos dos fármacos , Fatores de Transcrição NFATC/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Nitroprussiato/farmacologia , Osteopontina/efeitos dos fármacos , Osteopontina/metabolismo , Pele/irrigação sanguínea , Taxa de Sobrevida , Ultrassonografia Doppler , Vasodilatadores/farmacologia
15.
Environ Pollut ; 257: 113540, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31708278

RESUMO

In plants, excess selenium (Se) causes toxicity, while the beneficial effects of nitric oxide (NO) have verified in plants under various abiotic conditions. In order to ensure safely Se-enriched rice production, the objective of the research was to clarify how exogenous NO alleviated high Se toxicity in rice. Under high Se (25 µM) stress, the effects of exogenous NO (by applying sodium nitroprusside, an exogenous NO donor) on growth parameters, Se content, Se speciation, photosynthesis, antioxidant system, expressions of Se transport and metabolism-related genes (phosphate transporter, OsPT2; S-adenosylmethionine synthase 1, OsSAMS1; cysteine synthase, OsCS; Se-binding protein gene, OsSBP1) in rice seedlings were investigated by a hydroponic experiment. The results showed that exogenous NO alleviated high Se-induced irreversible damage to root morphology, growth, photosynthesis, antioxidant capacity and decreased the contents of MDA, H2O2 and proline significantly in rice seedlings. Compared with high Se treatment, application of exogenous NO reduced root Se content (10%), and the Se(VI) decreased by 100% in root and shoot. Besides, exogenous NO decreased the accumulation of inorganic Se speciation in rice roots and shoots. Also, the qRT-PCR analysis showed that down-regulated gene expressions of OsPT2, OsSAMS1 and OsCS affected significantly via exogenous NO. So, the exogenous NO could effectively decrease the toxicity of high Se treatment in rice.


Assuntos
Óxido Nítrico/metabolismo , Oryza/efeitos dos fármacos , Selênio/toxicidade , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Transporte Biológico/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Hidroponia , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Oryza/metabolismo , Oryza/fisiologia , Fotossíntese/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Selênio/metabolismo , Poluentes do Solo/metabolismo
16.
Med Sci Sports Exerc ; 52(3): 627-636, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31609299

RESUMO

INTRODUCTION: The study evaluated the role of lifelong physical activity for leg vascular function in postmenopausal women (61 ± 1 yr). METHOD: The study design was cross-sectional with three different groups based on self-reported physical activity level with regard to intensity and volume over the past decade: inactive (n = 14), moderately active (n = 12), and very active (n = 15). Endothelial-dependent and smooth muscle-dependent leg vascular function were assessed by ultrasound Doppler measurements of the femoral artery during infusion of acetylcholine (Ach), the nitric oxide (NO) donor sodium nitroprusside and the prostacyclin analog epoprostenol. Thigh muscle biopsies, arterial and venous plasma samples were obtained for assessment of vasodilator systems. RESULTS: The very active group was found to have 76% greater responsiveness to Ach compared with the sedentary group accompanied by 200% higher prostacyclin synthesis during Ach infusion. Smooth muscle cell responsiveness to sodium nitroprusside and epoprostenol was not different between groups. The protein amount of endothelial NO synthase and endogenous antioxidant enzymes in muscle tissue was higher in the very active than the inactive group. The moderately active group had a similar endothelial and smooth muscle cell responsiveness as the inactive group. A secondary comparison with a smaller group (n = 5) of habitually active young (24 ± 2 yr) women indicated that smooth muscle cell responsiveness and endothelial responsiveness are affected by age per se. CONCLUSIONS: This study shows that leg vascular function and the potential to form prostacyclin and NO in late postmenopausal women, is influenced by the extent of lifelong physical activity.


Assuntos
Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Perna (Membro)/irrigação sanguínea , Músculo Liso Vascular/fisiologia , Pós-Menopausa/fisiologia , 6-Cetoprostaglandina F1 alfa/sangue , Acetilcolina/farmacologia , Idoso , Estudos Transversais , Epoprostenol/farmacologia , Feminino , Artéria Femoral/fisiologia , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/enzimologia , Músculo Liso Vascular/efeitos dos fármacos , Nitroprussiato/farmacologia , Norepinefrina/sangue , Fluxo Sanguíneo Regional , Vasodilatadores/farmacologia
17.
Chemosphere ; 239: 124523, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499308

RESUMO

Arsenic (As) is a toxic metalloid that severely hampers plant growth and also poses health risks for humans through the food chain. Although nitric oxide (NO) is known to improve plant resistance to multiple stresses including metal toxicity, little is known about its role in the As tolerance of hyperaccumulator plants. This study investigates the role of the exogenously applied NO donor, sodium nitroprusside (SNP), in improving the As tolerance of Isatis cappadocica, which has been reported to hyperaccumulate As. Exposure to toxic As concentrations significantly increases NO production and damages the cell membrane, as indicated by increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, thereby reducing plant growth. However, the addition of SNP improves growth and alleviates As-induced oxidative stress by enhancing the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), as well as proline and thiol concentrations, thereby confirming the beneficial role played by NO in increasing As stress tolerance. Furthermore, the As-induced decrease in growth and the increase in oxidative stress were more marked in the presence of bovine hemoglobin (Hb; a NO scavenger) and N(G)-nitro-l-arginine methyl ester (l-NAME; a NO synthase inhibitor), thus demonstrating the protective role of NO against As toxicity. The reduction in NO concentrations by l-NAME suggests that NOS-like activity is involved in the generation of NO in response to As in I. cappadocica.


Assuntos
Antioxidantes/metabolismo , Arsênico/toxicidade , Isatis/efeitos dos fármacos , Óxido Nítrico/metabolismo , Nitroprussiato/farmacologia , Animais , Ascorbato Peroxidases/metabolismo , Bovinos , Membrana Celular/patologia , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Isatis/metabolismo , Malondialdeído/metabolismo , Doadores de Óxido Nítrico , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo
18.
Physiol Plant ; 168(2): 361-373, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31433490

RESUMO

Sodium nitroprusside (SNP) and hydrogen peroxide (H2 O2 ), as priming agents, have the well-recorded property to increase plant tolerance against a range of different abiotic stresses such as salinity. In this regard, the present study was conducted to evaluate the effect of different levels of SNP (100 and 200 µM) and H2 O2 (2.5 and 5 mM) as well as their combinations under salt stress (0 and 50 mM NaCl) on key physiological and biochemical attributes of the economically important aromatic plant basil (Ocimum basilicum L.) grown under hydroponic culture. Results revealed that morphological parameters such as plant height, root length, leaf fresh and dry weights (FW and DW) were significantly decreased by salinity stress, while SNP and H2 O2 treatments, alone or combined, increased FW and DW thus enhancing plant tolerance to salt stress. Furthermore, 200 µM SNP + 2.5 mM H2 O2 appeared to be the most effective treatment by causing significant increase in chlorophyll a and b, anthocyanin content and guaiacol peroxidase and ascorbate peroxidase enzymes activities under saline condition. In addition, analytical measurements showed that essential oil profile (concentration of main components) under salt stress was mostly affected by SNP and H2 O2 treatments. The highest increase was observed for methyl chavicol (43.09-69.91%), linalool (4.8-17.9%), cadinol (1.5-3.2%) and epi-α-cadinol (0.18-10.75%) compounds. In conclusion, current findings demonstrated a positive crosstalk between SNP and H2 O2 toward improved basil plant tolerance to salt stress, linked with regulation of essential oil composition.


Assuntos
Peróxido de Hidrogênio/farmacologia , Nitroprussiato/farmacologia , Ocimum basilicum/fisiologia , Estresse Salino , Ocimum basilicum/efeitos dos fármacos , Óleos Voláteis/química , Óleos Vegetais/química , Salinidade
19.
Physiol Plant ; 168(3): 576-589, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31102278

RESUMO

A variety of cellular responses is needed to ensure the plants survival during drought, but little is known about the signaling mechanisms involved in this process. Soybean cultivars (EMBRAPA 48 and BR 16, tolerant and sensitive to drought, respectively) were exposed to the following treatments: control conditions (plants in field capacity), drought (20% of available water in the soil), sodium nitroprusside (SNP) treatment (plants irrigated and treated with 100-µM SNP [SNP-nitric oxide (NO) donor molecule], and Drought + SNP (plants subjected to drought and SNP treatment). Plants remained in these conditions until the reproductive stage and were evaluated for physiological (photosynthetic pigments, chlorophyll a fluorescence and gas exchange rates), hydraulic (water potential, osmotic potential and leaf hydraulic conductivity) and morpho-anatomical traits (biomass, venation density and stomatal characterization). Exposure to water deficit considerably reduced water potential in both cultivars and resulted in decrease in photosynthesis and biomass accumulation. The addition of the NO donor attenuated these damaging effects of water deficit and increased the tolerance index of both cultivars. The results showed that NO was able to reduce plant's water loss, while maintaining their biomass production through alteration in stomatal characteristics, hydraulic conductivity and the biomass distribution pattern. These hydraulic and morpho-anatomical alterations allowed the plants to obtain, transport and lose less water to the atmosphere, even in water deficit conditions.


Assuntos
Secas , Óxido Nítrico/fisiologia , Soja/fisiologia , Estresse Fisiológico , Água , Clorofila A , Nitroprussiato/farmacologia , Fotossíntese , Folhas de Planta/fisiologia
20.
Biochem Pharmacol ; 173: 113686, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31678494

RESUMO

Endothelial dysfunction predisposing to cardiovascular diseases is defined as an imbalance in the production of vasodilating factors, such as nitric oxide (NO), and vasoconstrictive factors. To insure its physiological role, NO, a radical with very short half-life, requires to be stored and transported to its action site. S-nitrosothiols (RSNOs) like S-nitrosoglutathione (GSNO) represent the main form of NO storage within the vasculature. The NO store formed by RSNOs is still bioavailable to trigger vasorelaxation. In this way, RSNOs are an emerging class of NO donors with a potential to restore NO bioavailability within cardiovascular disorders. The aim of this study was to compare S-nitrosothiols ability, formed of peptide (glutathione) like the physiologic GSNO or derived from amino acids (cysteine, valine) like the synthetics S-nitroso-N-acetylcysteine (NACNO) and S-nitroso-N-acetylpenicillamine (SNAP), respectively, to produce a vascular store of NO either in endothelium-intact or endothelium-removed aortae in order to evaluate whether RSNOs can be used as therapeutics to compensate endothelial dysfunction. Sodium nitroprusside (SNP), a marketed drug already in clinics, was used as a non-RSNO NO-donor. Endothelium-intact or endothelium-removed aortae, isolated from normotensive Wistar rats, were exposed to RSNOs or SNP. Then, NO-derived (NOx) species, representing the NO store inside the vascular wall, were quantified using the diaminonaphthalene probe coupled to mercuric ions. The bioavailability of the NO store and its ability to induce vasodilation was tested using N-acetylcysteine, then its ability to counteract vasoconstriction was challenged using phenylephrine (PHE). All the studied RSNOs were able to generate a NO store materialized by a three to five times increase in NOx species inside aortae. NACNO was the most potent RSNO to produce a vascular NO store bioavailable for vasorelaxation and the most efficient to induce vascular hyporeactivity to PHE in endothelium-removed aortae. GSNO and SNAP were equivalent and more efficient than SNP. In endothelium-intact aortae, the NO store was also formed whereas it seemed less available for vasorelaxation and did not influence PHE-induced vasoconstriction. In conclusion, RSNOs - NACNO in a better extent - are able to restore NO bioavailability as a functional NO store within the vessel wall, especially when the endothelium is removed. This was associated with a hyporeactivity to the vasoconstrictive agent phenylephrine. Treatment with RSNOs could present a benefit to restore NO-dependent functions in pathological states associated with injured endothelium.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/metabolismo , S-Nitrosotióis/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/metabolismo , Aorta Torácica/fisiologia , Cisteína/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Glutationa/metabolismo , Técnicas In Vitro , Masculino , Doadores de Óxido Nítrico/metabolismo , Nitroprussiato/farmacologia , Fenilefrina/farmacologia , Ratos Wistar , S-Nitrosotióis/metabolismo , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia
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