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2.
Life Sci ; 234: 116772, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31422097

RESUMO

AIMS: Ligation of the urethra to create partial bladder outlet obstruction has widely been used as an animal model of bladder obstruction, although obstructive bladder dysfunction may be due to both mechanical and functional obstruction. Previous studies in rodents have demonstrated that long-term nitric oxide (NO) deficiency can lead to detrusor overactivity, and lack of NO may thus cause impairment of bladder outlet relaxation. The aim of this study was to define the characteristics of bladder and urethral dysfunction induced by chronic NO deficiency through both in vivo and in vitro investigations. MAIN METHODS: Rats were divided into two groups, and one group received an NO synthase inhibitor (Nω-nitro-L-arginine methyl ester hydrochloride: L-NAME) in the drinking water for 4 weeks. Bladder and urethral function were evaluated by continuous cystometry and isovolumetric cystometry. In vitro functional studies of detrusor strips and measurement of the mRNA and protein expression of an ischemic marker and a gap junction protein were also performed in separate rats. KEY FINDINGS: L-NAME administration raised blood pressure and decreased plasma nitrite/nitrate level compared to the control group. L-NAME treatment increased the frequency of bladder contractions and the residual volume, and elevated urethral pressure and bladder contraction pressure. In addition, carbachol-induced contraction was reduced in isolated detrusor strips from the L-NAME group, and bladder expression of HIF-1 and connexin 43 showed upregulation. SIGNIFICANCE: These findings suggest that chronic administration of L-NAME to rats induces bladder hyperactivity with residual urine, and may provide a useful model of functional bladder obstruction.


Assuntos
NG-Nitroarginina Metil Éster , Óxido Nítrico Sintase/antagonistas & inibidores , Obstrução do Colo da Bexiga Urinária/induzido quimicamente , Obstrução do Colo da Bexiga Urinária/fisiopatologia , Animais , Modelos Animais de Doenças , Feminino , Nitratos/sangue , Óxido Nítrico Sintase/metabolismo , Nitritos/sangue , Ratos , Ratos Sprague-Dawley , Uretra/metabolismo , Uretra/fisiopatologia , Bexiga Urinária/metabolismo , Bexiga Urinária/fisiopatologia , Obstrução do Colo da Bexiga Urinária/sangue
3.
J Assist Reprod Genet ; 36(8): 1721-1736, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31325069

RESUMO

PURPOSE: Nitric oxide (NO) is a free radical synthesized mainly by nitric oxide synthases (NOSs). NO regulates many aspects in sperm physiology in different species. However, in vitro studies investigating NOS distribution, and how NO influences sperm capacitation and fertilization (IVF) in porcine, have been lacking. Therefore, our study aimed to clarify these aspects. METHODS: Two main experiments were conducted: (i) boar spermatozoa were capacitated in the presence/absence of S-nitrosoglutathione (GSNO), a NO donor, and two NOS inhibitors, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) and aminoguanidine hemisulfate salt (AG), and (ii) IVF was performed in the presence or not of these supplements, but neither the oocytes nor the sperm were previously incubated in the supplemented media. RESULTS: Our results suggest that NOS distribution could be connected to pathways which lead to capacitation. Treatments showed significant differences after 30 min of incubation, compared to time zero in almost all motility parameters (P < 0.05). When NOSs were inhibited, three protein kinase A (PKA) substrates (~ 75, ~ 55, and ~50 kDa) showed lower phosphorylation levels between treatments (P < 0.05). No differences were observed in total tyrosine phosphorylation levels evaluated by Western blotting nor in situ. The percentage of acrosome-reacted sperm and phosphatidylserine translocation was significantly lower with L-NAME. Both inhibitors reduced sperm intracellular calcium concentration and IVF parameters, but L-NAME impaired sperm ability to penetrate denuded oocytes. CONCLUSIONS: These findings point out to the importance of both sperm and cumulus-oocyte-derived NO in the IVF outcome in porcine.


Assuntos
Inibidores Enzimáticos/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/metabolismo , Oócitos/fisiologia , Capacitação Espermática/fisiologia , Motilidade Espermática/fisiologia , Reação Acrossômica , Animais , Feminino , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Oócitos/citologia , Oócitos/efeitos dos fármacos , Capacitação Espermática/efeitos dos fármacos , Motilidade Espermática/efeitos dos fármacos , Suínos
4.
Redox Biol ; 26: 101238, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31200239

RESUMO

L-NG-Nitro arginine methyl ester (L-NAME) has been widely applied for several decades in both basic and clinical research as an antagonist of nitric oxide synthase (NOS). Herein, we show that L-NAME slowly releases NO from its guanidino nitro group. Daily pretreatment of rats with L-NAME potentiated mesenteric vasodilation induced by nitrodilators such as nitroglycerin, but not by NO. Release of NO also occurred with the NOS-inactive enantiomer D-NAME, but not with L-arginine or another NOS inhibitor L-NMMA, consistent with the presence or absence of a nitro group in their structure and their nitrodilator-potentiating effects. Metabolic conversion of the nitro group to NO-related breakdown products was confirmed using isotopically-labeled L-NAME. Consistent with Fenton chemistry, transition metals and reactive oxygen species accelerated the release of NO from L-NAME. Both NO production from L-NAME and its nitrodilator-potentiating effects were augmented under inflammation. NO release by L-NAME can confound its intended NOS-inhibiting effects, possibly by contributing to a putative intracellular NO store in the vasculature.


Assuntos
Inibidores Enzimáticos/farmacologia , NG-Nitroarginina Metil Éster/farmacologia , Nitroglicerina/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Arginina/farmacologia , Feminino , Artérias Mesentéricas/efeitos dos fármacos , Camundongos , Miografia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Ovinos , Estereoisomerismo , Vasodilatação/fisiologia , ômega-N-Metilarginina/farmacologia
5.
Int J Mol Sci ; 20(9)2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035686

RESUMO

The Pringle maneuver (PM) has been widely used to control blood loss during liver resection. However, hepatic inflow occlusion can also result in hepatic ischemia-reperfusion injury (IRI), especially in patients with a cholestatic, fibrotic, or cirrhotic liver. Here we investigate a nitric oxide synthase (NOS) inhibitor N-Nitroarginine methyl ester (L-NAME) on IRI after the PM and partial hepatectomy of cholestatic livers induced by bile duct ligation (BDL) in rats. Control group (non-BDL/no treatment), BDL + T group (BDL/L-NAME treatment) and BDL group (BDL/no treatment) were analyzed. Cholestasis was induced by BDL in the L-NAME and BDL group and a 50% partial hepatectomy with PM was performed. L-NAME was injected before PM in the BDL + T group. Hepatocellular damage, portal venous flow, microcirculation, endothelial lining, and eNOS, iNOS, interleukin (IL)-6, and transforming growth factor-ß (TGF-ß) were evaluated. Microcirculation of the liver in the BDL + T group tended to be higher. Liver damage and apoptotic index were significantly lower and Ki-67 labeling index was higher in the BDL + T group while iNOS and TGF-ß expression was decreased. This was corroborated by a better preserved endothelial lining. L-NAME attenuated IRI following PM and improved proliferation/regeneration of cholestatic livers. These positive effects were considered as the result of improved hepatic microcirculation, prevention of iNOS formation, and TGF-ß mRNA upregulation.


Assuntos
Colestase Intra-Hepática/complicações , Colestase Intra-Hepática/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/metabolismo , Animais , Biomarcadores , Colestase Intra-Hepática/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Ácido Hialurônico/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imuno-Histoquímica , Mediadores da Inflamação/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Microcirculação/efeitos dos fármacos , Óxido Nítrico/metabolismo , Ratos , Traumatismo por Reperfusão/patologia
6.
Neurobiol Learn Mem ; 162: 15-22, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31047996

RESUMO

Reciprocal connections between the mediodorsal thalamic nucleus (MD) and the prefrontal cortex (PFC) are important for memory processes. Since the co-abuse of nicotine and ethanol affects memory formation, this study investigated the effect of nitric oxide inhibition in the MD on memory retrieval induced by co-administration of nicotine and ethanol. Subsequently, western blot analysis was used to evaluate how this change would alter the PFC pCREB/CREB signaling pathway. Male Wistar rats were bilaterally cannulated into the MD and the memory retrieval was measured by passive avoidance task. Intraperitoneal (i.p.) administration of ethanol (1 g/kg, i.p) 30 min before the test impaired memory retrieval and caused ethanol-induced amnesia. Subcutaneous (s.c.) administration of nicotine (0.05-0.2 mg/kg, s.c.) prevented ethanol-induced amnesia and improved memory retrieval. Intra-MD microinjection of a nitric oxide synthase (NOS) inhibitor, L-NAME (0.5-1 µg/rat) inhibited the improving effect of nicotine (0.2 mg/kg, s.c.) on ethanol-induced amnesia, while intra-MD microinjection of a precursor of nitric oxide, l-arginine (0.25-1 µg/rat), potentiated such effect. Noteworthy, intra-MD microinjection of the same doses of L-NAME or l-arginine by itself had no effect on memory retrieval. Furthermore, intra-MD microinjection of L-NAME (0.05, 0.1 and 0.3 µg/rat) reversed the l-arginine improving effect on nicotine response. Successful memory retrieval significantly increased the p-CREB/CREB ratio in the PFC tissue. Ethanol-induced amnesia, however, decreased this ratio in the PFC while the co-administration of nicotine and ethanol increased the PFC CREB signaling. Interestingly, the inhibitory effect of L-NAME and the potentiating effect of l-arginine on nicotine response were associated with the decrease and increase of the PFC p-CREB/CREB ratio respectively. It can be concluded that MD-PFC connections are involved in the combined effects of nicotine and ethanol on memory retrieval. The mediodorsal thalamic NO system possibly mediated this interaction via the pCREB/CREB signaling pathways in the PFC.


Assuntos
Etanol/farmacologia , Núcleo Mediodorsal do Tálamo/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Nicotina/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Córtex Pré-Frontal/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Masculino , Núcleo Mediodorsal do Tálamo/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Agonistas Nicotínicos/farmacologia , Óxido Nítrico/metabolismo , Fosforilação/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Wistar
7.
Amino Acids ; 51(7): 983-990, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31062169

RESUMO

Rheumatoid Arthritis (RA) confers an increased cardiovascular disease (CVD) risk which accounts for much of the premature morbidity and mortality observed in this population. Alterations in vascular function and morphology leading to increased atherosclerotic burden are considered the main drivers of CVD in RA individuals with systemic inflammation playing a key role in the dysregulation of endothelial homeostasis and initiation of vascular injury. Dimethylarginines are endogenous inhibitors of nitric oxide (NO) synthase and have emerged as novel, independent biomarkers of CVD in a wide range of conditions associated with vascular pathology. In RA several reports have demonstrated abnormal dimethylarginine metabolism attributable to various factors such as systemic inflammation, decreased degradation or upregulated synthesis. Although a causal relationship between dimethylarginines and vascular damage in RA has not been established, the tight interrelations between inflammation, dimethylarginines and endothelial dysfunction suggest that determination of dimethylarginine regulators may shed more light in the pathophysiology of the atherosclerotic process in RA and may also provide new therapeutic targets. The Alanine-Glyoxylate Aminotransferase 2 (AGTX2)-dependent pathway is a relatively recently discovered alternative pathway of dimethylarginine catabolism and its role on RA-related atherosclerotic disease is yet to be established. As factors affecting dimethylarginine concentrations linked to CVD risk and endothelial dysfunction are of prominent clinical relevance in RA, we present preliminary evidence that gene variants of AGTX-2 may influence dimethylarginine levels in RA patients and provide the rationale for larger studies in this field.


Assuntos
Arginina/análogos & derivados , Artrite Reumatoide/metabolismo , Doenças Cardiovasculares/genética , Transaminases/genética , Arginina/metabolismo , Artrite Reumatoide/complicações , Artrite Reumatoide/genética , Artrite Reumatoide/fisiopatologia , Aterosclerose/patologia , Aterosclerose/fisiopatologia , Biomarcadores/sangue , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/fisiopatologia , Endotélio Vascular/enzimologia , Endotélio Vascular/fisiopatologia , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/antagonistas & inibidores , Polimorfismo de Nucleotídeo Único , Transaminases/metabolismo
8.
Molecules ; 24(9)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052164

RESUMO

Myocardial infarction (MI) remains the leading cause of death worldwide. We aimed to investigate the effect of NO deficiency on selective biochemical parameters within discreet myocardial zones after experimentally induced MI. To induce MI, the left descending coronary artery was ligated in two groups of 16-week-old WKY rats. In one group, NO production was inhibited by L-NAME (20 mg/kg/day) administration four weeks prior to ligation. Sham operations were performed on both groups as a control. Seven days after MI, we evaluated levels of nitric oxide synthase (NOS) activity, eNOS, iNOS, NFÒ¡B/p65 and Nrf2 in ischemic, injured and non-ischemic zones of the heart. Levels of circulating TNF-α and IL-6 were evaluated in the plasma. MI led to increased NOS activity in all investigated zones of myocardium as well as circulating levels of TNF-α and IL-6. L-NAME treatment decreased NOS activity in the heart of sham operated animals. eNOS expression was increased in the injured zone and this could be a compensatory mechanism that improves the perfusion of the myocardium and cardiac dysfunction. Conversely, iNOS expression increased in the infarcted zone and may contribute to the inflammatory process and irreversible necrotic changes.


Assuntos
Adaptação Fisiológica , Pressão Sanguínea , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Óxido Nítrico/metabolismo , Animais , Biomarcadores , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal , Citocinas/metabolismo , Ativação Enzimática , Expressão Gênica , Hipertensão/etiologia , NG-Nitroarginina Metil Éster/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Tamanho do Órgão , Ratos
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 218: 374-387, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31030004

RESUMO

The inhibition of the enzyme Nitric Oxide Synthase by a bioactive compounds results in it possessing anti-inflammatory property. The ability of Andrographolide and its derivative Isoandrographolide to inhibit Nitric Oxide Synthase was studied using computational and experimental techniques. A combination of UV Spectroscopic and DFT computational techniques were used to calculate the molecular descriptors of the title compounds which were used to establish relationship with its biological activity. The drug-likeness of the compounds was estimated using Lipinski's rule. Molecular dynamics and docking studies were carried out to test for the structural and energetic favourability of the title compounds(ligand) being bound to Nitric Oxide Synthase(Protein) to induce inhibition. The force constant data obtained from IR spectroscopy was used in aid to parametrize force fields used in molecular dynamics simulation. The DFT method was used to perform NBO analysis that revealed the charge transfer interactions responsible for its biological properties. The Molecular Electrostatic Potential (MEP) plot revealed the regions of electrophilic and nucleophilic reactivity of the title compounds. MTT (3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay was carried out which revealed the cytotoxicity at different concentrations of the title compounds by which means the biologically safe concentration was determined and therefore at this biologically safe concentration the ability of the compounds to inhibit Nitric Oxide formation was determined. Quantitative Structure-Activity Studies (QSAR) were used to furnish relationship between molecular descriptors and the Nitric Oxide Synthase inhibition activity resulting in anti-inflammatory property, based on the chosen molecular descriptors suggestions were made for the search of more potent Nitric Oxide Synthase inhibitors in the Andrographolide derivative family of compounds.


Assuntos
Diterpenos/química , Diterpenos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Camundongos , Modelos Moleculares , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Relação Quantitativa Estrutura-Atividade , Células RAW 264.7 , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
10.
Artigo em Inglês | MEDLINE | ID: mdl-30991078

RESUMO

Nitric oxide (NO) triggers escape reactions in the dorsal periaqueductal gray matter (dPAG), a core structure mediating panic-associated response, and decreases the release of BDNF in vitro. BDNF mediates the panicolytic effect induced by antidepressant drugs and produces these effects per se when injected into the dPAG. Based on these findings, we hypothesize that nitric oxide synthase (NOS) inhibitors would have panicolytic properties associated with increased BDNF signaling in the dPAG. We observed that the repeated (7 days), but not acute (1 day), systemic administration of the NOS inhibitor aminoguanidine (AMG; 15 mg/kg/day) increased the latency to escape from the open arm of the elevated T-maze (ETM) and inhibited the number of jumps in hypoxia-induced escape reaction in rats, suggesting a panicolytic-like effect. Repeated, but not acute, AMG administration (15 mg/kg) also decreased nitrite levels and increased TRKB phosphorylation at residues Y706/7 in the dPAG. Notwithstanding the lack of AMG effect on total BDNF levels in this structure, the microinjection of the TRK antagonist K252a into the dPAG blocked the anti-escape effect of this drug in the ETM. Taken together our data suggest that the inhibition of NO production by AMG increases the levels of pTRKB, which is required for the panicolytic-like effect observed.


Assuntos
Ansiolíticos/farmacologia , Guanidinas/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Pânico/efeitos dos fármacos , Receptor trkB/efeitos dos fármacos , Animais , Western Blotting , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Reação de Fuga/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Nitritos/metabolismo , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Substância Cinzenta Periaquedutal/metabolismo , Substância Cinzenta Periaquedutal/fisiologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Wistar , Receptor trkB/antagonistas & inibidores , Receptor trkB/metabolismo , Transdução de Sinais/efeitos dos fármacos
11.
Food Funct ; 10(5): 2528-2537, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-30993288

RESUMO

In order to study the in vitro effect of flavan-3-ol (+)-catechin on the enzymatic activities of mitochondrial complex I and nitric oxide synthase (mtNOS), as well as the consequences on the membrane potential and H2O2 production rate, isolated mitochondria from rat heart were exposed to 3 nM to 100 µM (+)-catechin. NADH-Q1 reductase (complex I) and mtNOS activities were inhibited 25% and 50%, respectively, by the addition of 10 nM (+)-catechin to the reaction medium. Moreover, in the nM range, (+)-catechin decreased state 4 mitochondrial membrane potential by about 10 mV, but failed to change the membrane potential measured in the presence of ADP. (+)-Catechin (10 nM) inhibited not only complex I activity, but also the H2O2 production rate (35%) sustained by malate-glutamate, in accordance with the decrease observed in mitochondrial membrane potential. Considering (+)-catechin concentrations lower than 10 nM, linear and positive correlations were obtained between mitochondrial complex I activity and either NO (r2 = 0.973) or H2O2 production rates (r2 = 0.958), suggesting a functional association among these parameters. Altogether, the results indicate that (+)-catechin, at nM concentrations, inhibits mitochondrial complex I activity, leading to membrane potential decline and consequently to reduction in H2O2 and NO production rates. The decrease in mtNOS activity could also be a consequence of the direct action of (+)-catechin on the NOS structure, this effect being in accordance with the functional interaction between complex I and mtNOS, as previously reported.


Assuntos
Catequina/farmacologia , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Coração/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Complexo I de Transporte de Elétrons/química , Complexo I de Transporte de Elétrons/metabolismo , Feminino , Cinética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Miocárdio/química , Miocárdio/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/química , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Sprague-Dawley
12.
BMC Plant Biol ; 19(1): 108, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894123

RESUMO

BACKGROUND: Nutrition with ammonium (NH4+) can enhance the drought tolerance of rice seedlings in comparison to nutrition with nitrate (NO3-). However, there are still no detailed studies investigating the response of nitric oxide (NO) to the different nitrogen nutrition and water regimes. To study the intrinsic mechanism underpinning this relationship, the time-dependent production of NO and its protective role in the antioxidant defense system of NH4+- or NO3--supplied rice seedlings were studied under water stress. RESULTS: An early NO burst was induced by 3 h of water stress in the roots of seedlings subjected to NH4+ treatment, but this phenomenon was not observed under NO3- treatment. Root oxidative damage induced by water stress was significantly higher for treatment with NO3- than with NH4+ due to reactive oxygen species (ROS) accumulation in the former. Inducing NO production by applying the NO donor 3 h after NO3- treatment alleviated the oxidative damage, while inhibiting the early NO burst by applying the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) increased root oxidative damage in NH4+ treatment. Application of the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester(L-NAME) completely suppressed NO synthesis in roots 3 h after NH4+ treatment and aggravated water stress-induced oxidative damage. Therefore, the aggravation of oxidative damage by L-NAME might have resulted from changes in the NOS-mediated early NO burst. Water stress also increased the activity of root antioxidant enzymes (catalase, superoxide dismutase, and ascorbate peroxidase). These were further induced by the NO donor but repressed by the NO scavenger and NOS inhibitor in NH4+-treated roots. CONCLUSION: These findings demonstrate that the NOS-mediated early NO burst plays an important role in alleviating oxidative damage induced by water stress by enhancing the antioxidant defenses in roots supplemented with NH4+.


Assuntos
Compostos de Amônio/farmacologia , Desidratação , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico/metabolismo , Oryza/fisiologia , Antioxidantes/metabolismo , Arginina/metabolismo , Citrulina/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Nitratos/metabolismo , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Nitroprussiato/farmacologia , Oryza/efeitos dos fármacos , Oxirredução , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo
13.
J Enzyme Inhib Med Chem ; 34(1): 753-760, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30829084

RESUMO

The aerial parts of Tetrastigma hemsleyanum (APTH) have been used as a functional tea in China. The purpose of the current study was to identify the bioactive constituents with inhibitory activity against soluble epoxide hydrolase (sEH) and inducible nitric oxide synthase (iNOS), which are jointly considered potential therapeutic targets for vascular system diseases. In the present study, 39 compounds (1-39) were isolated from the APTH. Among them, compounds 8, 10, 12, 16, 17, 19, and 32 displayed potential activities, with IC50 values ranging from 4.5 to 9.5 µM, respectively, and all in non-competitive inhibition mode. Compounds 5, 10, 12, 19, and 32 displayed potent iNOS inhibitory effects, with IC50 values ranging from 15.6 to 47.3 µM. The results obtained in this work contribute to a better understanding of the pharmacological activities of T. hemsleyanum and its potential application as a functional food.


Assuntos
Epóxido Hidrolases/antagonistas & inibidores , Óxido Nítrico Sintase/antagonistas & inibidores , Fenóis/farmacologia , Componentes Aéreos da Planta/química , Extratos Vegetais/farmacologia , Vitaceae/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Epóxido Hidrolases/metabolismo , Camundongos , Modelos Moleculares , Estrutura Molecular , Óxido Nítrico Sintase/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Células RAW 264.7 , Solubilidade , Relação Estrutura-Atividade
14.
Neuropharmacology ; 150: 70-79, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30898570

RESUMO

Elimination of brain cholesterol occurs in the form of 24S-hydroxycholesterol (24S-HCh) that may modulate physiological processes outside the brain. Here, using microelectrode recording of postsynaptic responses (end-plate potentials, EPPs) and fluorescent marker (FM1-43) for endo-exocytosis we studied the effects of prolonged application of 24S-HCh (2.5 h, 0.4 µM) on the neurotransmission in the mice diaphragm. 24S-HCh enhanced the depression of EPP amplitude (indicator of neurotransmitter release) and suppressed the FM1-43 dye unloading from nerve terminals (indicator of exocytosis) during electrical nerve stimulation at 20 Hz, without affecting miniature EPP amplitude and frequency. Comparison of the rates of neurotransmitter and FM1-43 releases suggested an increase in time required for the synaptic vesicle reuse. Additionally, 24S-HCh potentiated an increase in DAF-FM fluorescence (a NO-sensitive marker) in response to 20 Hz stimulation. All effects of 24S-HCh were completely prevented by liver X receptor antagonist. Either inhibitors of NO synthases (TRIM, cavtratin) or protein synthesis blocker counteracted the 24S-HCh-mediated enhancement in DAF-FM fluorescence, while inhibition of NO production with l-NAME or cavtratin and extracellular NO chelation suppressed the effect of 24S-HCh on FM1-43 dye loss during 20 Hz activity. Pretreatment for 5 days with inhibitor of 24S-HCh synthesis (voriconazole) had opposite effects on the FM1-43 unloading and NO synthesis. These data suggest that prolonged exposure to 24S-HCh attenuates recruitment of synaptic vesicle to exocytosis during 20 Hz stimulation acting via liver Ð¥ receptor/NO-dependent signaling.


Assuntos
Hidroxicolesteróis/farmacologia , Receptores X do Fígado/metabolismo , Junção Neuromuscular/efeitos dos fármacos , Óxido Nítrico Sintase/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , Caveolina 1/farmacologia , Inibidores Enzimáticos/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Masculino , Camundongos , NG-Nitroarginina Metil Éster/farmacologia , Junção Neuromuscular/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/efeitos dos fármacos
15.
J Vet Pharmacol Ther ; 42(3): 361-367, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30888081

RESUMO

Endothelial dysfunction contributes to the development of ungulate's laminitis. Although extensively studied in equines, the endothelial function is not fully examined in bovine digital veins (BDVs). BDVs were studied under isometric conditions to describe the acetylcholine (ACh) endothelium-dependent relaxation. Concentration-response curves were constructed to phenylephrine, ACh, and sodium nitroprusside (SNP). Relaxation responses were evaluated using either phenylephrine or depolarizing high-potassium Krebs solution (DKS) as precontraction agents. Endothelium denudation and incubation with L-NAME (300 µM), indomethacin (10 µM) or both were used to explore endothelial-mediated mechanisms. Endothelium denudation did not modify phenylephrine and SNP responses, however, significantly (p < 0.05) converted a relaxation (63.2 ± 5%) response to ACh into a contraction (30.3±9%). The ACh-evoked relaxation was significantly (p < 0.05) reduced in the presence of indomethacin (37.5 ± 6%) and L-NAME (6.40 ± 2%). The presence of both inhibitors abolished the ACh-evoked relaxation. Although DKS caused a higher precontraction than phenylephrine, ACh-evoked relaxation (22.4 ± 3.4%) was still observed and was reduced by the combination of inhibitors (7.0 ± 1.0%). The ACh endothelium-dependent relaxation in BDVs is essentially mediated by nitric oxide and endothelium-derived prostanoids. The BDV endothelium function is a dynamic component in the control of the bovine digital blood flow, particularly under endothelial dysfunction conditions when venoconstriction might lead to postcapillary resistance increase.


Assuntos
Endotélio Vascular/metabolismo , Óxido Nítrico/fisiologia , Prostaglandinas/fisiologia , Vasodilatação , Veias/metabolismo , Acetilcolina/farmacologia , Animais , Bovinos , Inibidores de Ciclo-Oxigenase/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Feminino , Casco e Garras/irrigação sanguínea , Indometacina/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Nitroprussiato/farmacologia , Fenilefrina/farmacologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Prostaglandinas/metabolismo , Veias/efeitos dos fármacos , Veias/fisiologia
16.
Life Sci ; 219: 336-342, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30684542

RESUMO

Chagas disease (CD) is an important cause of cardiomyopathy in South America. The pathophysiology of CD is still a matter of debate. Renin Angiotensin System (RAS) components are clearly involved in cardiovascular diseases. RAS molecules interact with nitric oxide (NO) pathway in blood vessel and heart tissue. Thus, the aim of this study is to investigate possible changes in RAS molecules during the infection with Y strain T. cruzi and in response to acute administration of an inhibitor of the enzyme NO synthase, l-NAME. Male Holtzman rats were inoculated intraperitoneally with Y strain T. cruzi and received l-NAME or tap water from one day before the infection until 13 or 17 days post infection (dpi). Angiotensin converting enzyme 1 (ACE1) levels were significantly higher at day 17 when compared to baseline in atrium, whereas, in ventricle, ACE2 levels were significantly higher in 13 dpi when compared to baseline. In response to l-NAME treatment, atrium tissue levels of ACE1 were significantly reduced in treated animals at day 17, while Angiotensin-(1-7) concentration in atrium significantly increased in this group at the same time-point. No changes were detected in RAS components in the ventricle. ACE2 levels in Soleus muscle were significantly reduced in treated animals at day 13. In conclusion, changes in RAS molecules were detected during acute phase of T. cruzi infection and the inhibition of NO synthesis clearly interfered with expression of ACE1 and Angiotensin-(1-7) in the atrium.


Assuntos
Cardiomiopatia Chagásica/metabolismo , Miocárdio/metabolismo , Óxido Nítrico/antagonistas & inibidores , Sistema Renina-Angiotensina , Animais , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Peptidil Dipeptidase A/metabolismo , Ratos Sprague-Dawley , Trypanosoma cruzi
17.
Eur J Pharmacol ; 847: 83-90, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658116

RESUMO

Current pharmacotherapies for voiding dysfunctions are in need of improvement. Lysophosphatidic acid (LPA) is a phospholipid that contracts the urethra by activating type 1 LPA receptors (LPA1). However, the role of LPA1 in regulating urethral tonus during urine voiding which primarily affects the voiding function has not been investigated. To elucidate the role of LPA1 in the regulation of urethral tonus during urine voiding, we investigated the effects of ASP6432, a novel LPA1 antagonist, and the α1-adrenoceptor antagonist tamsulosin on urethral perfusion pressure (UPP) at the filling phase (UPPbase) and the minimum UPP at the voiding phase (UPPnadir) in anesthetized rats under isovolumetric conditions. We further evaluated the effects of ASP6432 and tamsulosin on voiding dysfunction characterized by changes in post-void residual urine (PVR) and voiding efficiency (VE) induced by the nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) in conscious rats using single cystometry. ASP6432 dose-dependently decreased UPPbase and UPPnadir, while tamsulosin reduced UPPbase but did not change UPPnadir. ASP6432 dose-dependently suppressed the L-NAME-induced increase in PVR and decrease in VE, whereas tamsulosin did not affect either PVR or VE. We demonstrate that ASP6432 reduced UPPnadir and ameliorated L-NAME-induced voiding dysfunction, neither of which were affected by tamsulosin. Our study results suggest that LPA1 has a significant role in regulating urethral tonus during urine voiding, and highlight the potential of ASP6432 for improving voiding dysfunctions associated with various lower urinary tract diseases.


Assuntos
NG-Nitroarginina Metil Éster/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Tansulosina/farmacologia , Uretra/efeitos dos fármacos , Bexiga Urinária/efeitos dos fármacos , Urina/fisiologia , Animais , Feminino , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Uretra/metabolismo , Bexiga Urinária/metabolismo , Doenças da Bexiga Urinária/tratamento farmacológico , Doenças da Bexiga Urinária/metabolismo
18.
Phytomedicine ; 56: 74-82, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30668356

RESUMO

BACKGROUND: Luehea divaricata Mart. (Malvaceae) is an important medicinal species widely used by indigenous and riverside populations of the Brazilian Pantanal region. It has been shown that the several extracts obtained from leaves of this species have important cardioprotective effects. Nevertheless, the secondary metabolites responsible for this activity, as well as the molecular mechanisms responsible for their pharmacological effects remain unknown. PURPOSE: To carry out a biomonitoring study to identify possible active metabolites present in different ESLD fractions and evaluate the mechanisms responsible for the vasodilatory effects on isolated perfused mesenteric beds. METHODS: First, ESLD was obtained from L. divaricata leaves and a liquid-liquid fractionation was performed. The resulting fractions were analyzed by liquid chromatography-mass spectrometry. Then, the possible vasodilatory effects of ESLD, chloroform, ethyl acetate, n-butanolic and aqueous fractions on perfused arterial mesenteric vascular beds were evaluated. Finally, the molecular mechanisms involved in vasodilator responses of the aqueous fraction and its chemical component, isovitexin, on the mesenteric arteriolar tone were also investigated. RESULTS: In preparations with functional endothelium ESLD, n-butanolic, aqueous fraction and isovitexin dose-dependently reduced the perfusion pressure in mesenteric vascular beds. Endothelium removal or inhibition of nitric oxide synthase enzymes by L-NAME reduced the vasodilatory effects induced by aqueous fraction and isovitexin. Perfusion with nutritive solution containing 40 mM KCl abolished the vasodilatory effect of all aqueous fractions and Isovitexin doses. Treatment with glibenclamide, a Kir6.1 (ATP-sensitive) potassium channels blocker, tetraethylammonium, a non-selective KCa (calcium-activated) potassium channels blocker, or apamin, a potent blocker of small conductance Ca2+-activated (SK KCa) potassium channels reduced by around 70% vasodilation induced by all aqueous fractions and isovitexin doses. In addition, association of tetraethylammonium and glibenclamide, or L-NAME and glibenclamide, fully inhibited aqueous fraction and Isovitexin -induced vasodilation. CONCLUSION: This study showed that AqueFr obtained from Luehea divaricata and its metabolite - isovitexin - has important vasodilatory effects on MVBs. Apparently, these effects are dependent on endothelium-NO release and both SK KCa K+ channels and Kir6.1 ATP-sensitive K+ channels activation in the vascular smooth muscle.


Assuntos
Apigenina/farmacologia , Malvaceae/química , Extratos Vegetais/farmacologia , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Brasil , Feminino , Glibureto/farmacologia , Canais KATP/antagonistas & inibidores , Canais KATP/metabolismo , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Técnicas de Cultura de Órgãos , Plantas Medicinais/química , Ratos Wistar , Vasodilatação/efeitos dos fármacos
19.
Arterioscler Thromb Vasc Biol ; 39(3): 319-330, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30650999

RESUMO

As a leading cause of death worldwide, cardiovascular disease is a global health concern. The development and progression of atherosclerosis, which ultimately gives rise to cardiovascular disease, has been causally linked to hypercholesterolemia. Mechanistically, the interplay between lipids and the immune system during plaque progression significantly contributes to the chronic inflammation seen in the arterial wall during atherosclerosis. Localized inflammation and increased cell-to-cell interactions may influence polarization and proliferation of immune cells via changes in amino acid metabolism. Specifically, the amino acids l-arginine (Arg), l-homoarginine (hArg) and l-tryptophan (Trp) have been widely studied in the context of cardiovascular disease, and their metabolism has been established as key regulators of vascular homeostasis, as well as immune cell function. Cyclic effects between endothelial cells, innate, and adaptive immune cells exist during Arg and hArg, as well as Trp metabolism, that may have distinct effects on the development of atherosclerosis. In this review, we describe the current knowledge surrounding the metabolism, biological function, and clinical perspective of Arg, hArg, and Trp in the context of atherosclerosis.


Assuntos
Aminoácidos/metabolismo , Aterosclerose/metabolismo , Animais , Arginase/antagonistas & inibidores , Arginase/metabolismo , Arginina/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/etiologia , Aterosclerose/imunologia , Progressão da Doença , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Homoarginina/metabolismo , Humanos , Hipercolesterolemia/complicações , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Subpopulações de Linfócitos/imunologia , Terapia de Alvo Molecular , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Triptofano/metabolismo , Vasculite/metabolismo
20.
J Leukoc Biol ; 105(1): 131-142, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30199117

RESUMO

Glucocorticoids (GCs) are potent anti-allergic compounds that function, at least in part, by inhibiting signaling pathways in mast cells. We hypothesized that the GC-induced mastocytopenia and suppression of mast cell activation are mediated by the advanced glycation end products (AGEs)/receptors of AGEs (RAGEs) signaling axis. We evaluated the role of AGEs in GC-mediated mastocytopenia and impaired mast cell degranulation in male Wistar rats and Swiss-Webster mice subcutaneously injected with dexamethasone or prednisolone (0.1 mg/kg) once a day for 21 consecutive days. The animals were treated with either the AGE inhibitor aminoguanidine (250 mg/kg), the RAGE antagonist FPS-ZM1 (1 mg/kg) or the galectin-3 antagonist GSC-100 (1 mg/kg) daily for 18 days, starting 3 days following GC treatment. Aminoguanidine inhibited GC-induced mast cell apoptosis and restored mast cell numbers in the pleural cavity of GC-treated rats. Aminoguanidine also reversed the GC-induced reduction in histamine release triggered by allergens or compound 48/80 in vitro. GC treatment induced RAGE and galectin expression in mast cells, and blocking these agents by FPS-ZM1 or GSC-100 significantly reversed mast cell numbers in the peritoneal cavity and mesenteric tissue of GC-treated mice. In addition, the combination of GC and AGE-induced mast cell apoptosis in vitro was inhibited by both FPS-ZM1 and GSC-100. We concluded that the GC-induced mastocytopenia and suppression of mast cell stimulation are associated with the gene transactivation of RAGE and galectin-3.


Assuntos
Glucocorticoides/farmacologia , Mastócitos/metabolismo , Receptor para Produtos Finais de Glicação Avançada/genética , Ativação Transcricional/genética , Animais , Apoptose/efeitos dos fármacos , Atrofia , Contagem de Células , Linhagem Celular , Dexametasona/farmacologia , Galectina 3/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Guanidinas/farmacologia , Linfopenia/patologia , Masculino , Mastócitos/efeitos dos fármacos , Camundongos , Células Musculares/efeitos dos fármacos , Células Musculares/metabolismo , Músculo Esquelético/patologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Ratos Wistar , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Albumina Sérica/metabolismo , Ativação Transcricional/efeitos dos fármacos , Perda de Peso
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