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1.
Int J Biol Macromol ; 253(Pt 3): 126797, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37703963

RESUMO

The creation of functional components with precise chemistries on carbohydrate polymers is of great significance for future wearable biomedicine and health management. Among various carbohydrate polymers, marine polysaccharide featured with antimicrobial, biodegradable and biocompatible properties is an ideal platform while the water-swelling nature makes it difficult to form stable interface. Here, well-dispersed silver nanoparticles have been in-situ assembled on hydrated alginate fabric (AF), involving chemical absorption of Ag ions and in-situ reduction of conductive Ag layer. Owing to the stable complex formed between Ag ions and carboxyl groups, the Ag-grafted AF exhibits superior Joule heating capability, including low operating voltage (1-3 V), high saturation temperature (63 °C), rapid response time (25 s) and outstanding durability against harsh conditions. Furthermore, the Ag-grafted AF demonstrates noticeable inhibition against E. coli and S. aureus as compared with the pristine AF. This work provides a rational strategy for the functionalization of hydrated polysaccharide and enables wearable thermotherapy devices for human health management.


Assuntos
Nanopartículas Metálicas , Dispositivos Eletrônicos Vestíveis , Humanos , Nanopartículas Metálicas/química , Escherichia coli , Alginatos , Staphylococcus aureus , Prata/química , Polímeros , Íons
2.
Eur J Neurol ; 30(11): 3529-3539, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36905309

RESUMO

BACKGROUND AND PURPOSE: Growing evidence suggests that abnormalities in brain-gut-microbiome (BGM) interactions are involved in the pathogenesis of irritable bowel syndrome (IBS). Our study aimed to explore alterations in dynamic functional connectivity (DFC), the gut microbiome and the bidirectional interaction in the BGM. METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI), fecal samples and clinical chacteristics were collected from 33 IBS patients and 32 healthy controls. We performed a systematic DFC analysis on rs-fMRI. The gut microbiome was analyzed by 16S rRNA gene sequencing. Associations between DFC characteristics and microbial alterations were explored. RESULTS: In the DFC analysis, four dynamic functional states were identified. IBS patients exhibited increased mean dwell and fraction time in State 4, and reduced transitions from State 3 to State 1. Aberrant temporal properties in State 4 were only evident when choosing a short window (36 s or 44 s). Decreased functional connectivity (FC) variability was found in State 1 and State 3 in IBS patients, two of which (independent component [IC]51-IC91, IC46-IC11) showed significant correlations with clinical characteristics. Additionally, we identified nine significantly differential abundances in microbial composition. We also found that IBS-related microbiota were associated with aberrant FC variability, although these exploratory results were obtained at an uncorrected threshold of significance. CONCLUSIONS: Although future studies are needed to confirm our results, the findings not only provide a new insight into the dysconnectivity hypothesis in IBS from a dynamic perspective, but also establish a possible link between DFC and the gut microbiome, which lays the foundation for future research on disrupted BGM interactions.

3.
Front Pharmacol ; 13: 904926, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36176442

RESUMO

The opioid system plays a crucial role in maintaining gastrointestinal homeostasis. Endogenous opioid peptide enkephalins have anti-inflammatory effect and participate in the treatment of inflammatory bowel diseases (IBDs). Here, we investigated the effect of natural enkephalinase inhibitor human opiorphin (HO) on dextran sodium sulfate (DSS)-induced colitis in mice. Our results showed that central administration of HO attenuated DSS-induced colitis, as indicated by the reduction of disease activity index (DAI) scores, macroscopic scores, histological scores, and the myeloperoxidase (MPO) activity. Moreover, HO alleviated DSS-induced inflammation by decreasing inflammatory cytokines TNF-α, IL-6, and IL-1ß, and increasing anti-inflammatory cytokine IL-10 in both serum and colon tissues in DSS-treated mice. The potential anti-inflammatory effect of HO at a dose of 40 µg/kg was observed as evidenced by a decrease in nuclear factor κB (NF-κB) p65, toll-like receptor-4 (TLR-4), iNOS, and COX-2. HO also improved intestinal barrier function by enhancing the expression of tight junction proteins. Furthermore, HO treatment significantly inhibited activities of neutral endopeptidase (NEP) and aminopeptidase N (APN), elevated serum enkephalins concentrations, and increased expressions of mu and delta opioid receptors. In addition, pretreatment with opioid receptor antagonist naloxone hydrochloride (NH) compromised the protective effect of HO and aggravated colitis symptoms, as indicated by inhibited anti-inflammatory effects, disrupted intestinal barrier function, and decreased opioid receptor activity. In conclusion, these data indicate that HO protects against DSS-induced colitis by inhibiting TLR4/NF-κB pathway activation and improving intestinal barrier function through activation of the endogenous opioid system. Therefore, targeting the opioid system with peptidase inhibitors intervention would be a novel strategy in the therapy of IBD.

4.
Gut Microbes ; 13(1): 1-18, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33764849

RESUMO

Recent studies into the beneficial effects of fermented foods have shown that this class of foods are effective in managing hyperuricemia and gout. In this study, the uric acid (UA) degradation ability of Limosilactobacillus fermentum JL-3 strain, isolated from "Jiangshui" (a fermented Chinese food), was investigated. In vitro results showed that JL-3 strain exhibited high degradation capacity and selectivity toward UA. After oral administration to mice for 15 days, JL-3 colonization was continuously detected in the feces of mice. The UA level in urine of mice fed with JL-3 was similar with the control group mice. And the serum UA level of the former was significantly lower (31.3%) than in the control, further confirmed the UA-lowering effect of JL-3 strain. Limosilactobacillus fermentum JL-3 strain also restored some of the inflammatory markers and oxidative stress indicators (IL-1ß, MDA, CRE, blood urea nitrogen) related to hyperuricemia, while the gut microbial diversity results showed that JL-3 could regulate gut microbiota dysbiosis caused by hyperuricemia. Therefore, the probiotic Limosilactobacillus fermentum JL-3 strain is effective in lowering UA levels in mice and could be used as a therapeutic adjunct agent in treating hyperuricemia.


Assuntos
Alimentos Fermentados/microbiologia , Gota/epidemiologia , Hiperuricemia/dietoterapia , Limosilactobacillus fermentum/isolamento & purificação , Limosilactobacillus fermentum/metabolismo , Probióticos , Ácido Úrico/metabolismo , Animais , Animais não Endogâmicos , Disbiose/microbiologia , Microbioma Gastrointestinal , Gota/prevenção & controle , Humanos , Hiperuricemia/metabolismo , Masculino , Camundongos , Estresse Oxidativo
5.
Artigo em Inglês | MEDLINE | ID: mdl-31297340

RESUMO

Diethylhexylphthalate (DEHP), acting as an endocrine disruptor, disturbed reproductive health. Here, we evaluated the effects of Lactobacillus plantarum TW1-1 (L. plantarum TW1-1) on DEHP-induced testicular damage in adult male mice. Results showed that oral supplementation of L. plantarum TW1-1 significantly increased the serum testosterone concentration, enhanced the semen quality, and attenuated gonad development defects in DEHP-exposed mice. L. plantarum TW1-1 also alleviated DEHP-induced oxidative stress and inflammatory responses by decreasing the mRNA expression and serum protein concentration of different inflammatory factors [tumor necrosis factor-α, interleukin (IL)-1ß and IL-6]. Furthermore, L. plantarum TW1-1 significantly reduced DEHP-induced intestinal hyper-permeability and the increase in the serum lipopolysaccharide level. Gut microbiota diversity analysis revealed that L. plantarum TW1-1 shifted the DEHP-disrupted gut microbiota to that of the control mice. At phylum level, L. plantarum TW1-1 reversed DEHP-induced Bacteroidetes increase and Firmicutes decrease, and restored Deferribacteres in DEHP-exposed mice. Spearman's correlation analysis showed that Bacteroidetes, Deferribacteres, and Firmicutes were associated with DEHP-induced testicular damage. In addition, the ratio of Firmicutes to Bacteroidetes (Firm/Bac ratio) significantly decreased from 0.28 (control group) to 0.13 (DEHP-exposed group), which was restored by L. plantarum TW1-1 treatment. Correlation analysis showed that the Firm/Bac ratio was negatively correlated with testicular damage and inflammation. These findings suggest that L. plantarum TW1-1 prevents DEHP-induced testicular damage via modulating gut microbiota and decreasing inflammation.


Assuntos
Dietilexilftalato/efeitos adversos , Microbioma Gastrointestinal/fisiologia , Inflamação/terapia , Lactobacillus plantarum/fisiologia , Doenças Testiculares/terapia , Testículo/efeitos dos fármacos , Animais , Bactérias/classificação , Modelos Animais de Doenças , Fezes/microbiologia , Expressão Gênica , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lipopolissacarídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Permeabilidade , Probióticos , RNA Ribossômico 16S/genética , Análise do Sêmen , Doenças Testiculares/induzido quimicamente , Testículo/patologia , Testosterona/sangue , Fator de Necrose Tumoral alfa/metabolismo
6.
Neurosci Lett ; 641: 62-69, 2017 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-28104434

RESUMO

Human opiorphin plays an important pharmacological functions in rats or mice. The present study was performed to investigate effects and underlying mechanism of central injected opiorphin on food intake and water intake in mice. Intracerebroventricularly (i.c.v.) administered opiorphin (5-20µg/kg) dose-dependently suppressed food intake in fasted mice, but had no influence on food intake in freely feeding mice. The cumulative food intake was significantly decreased at 60min after injection of 10 and 20µg/kg opiorphin and the food intake was significantly reduced during the 20-60min period after treatment. Non-selected opiate receptor antagonist naloxone could fully block the inhibitory effect induced by opiorphin on cumulative food intake at 60min in fasted mice, suggesting that the anorexic effect of opiorphin was related to the opioid system. Moreover, the anorexic effect induced by opiorphin in fasted mice was also significantly inhibited by pretreatment with captopril or valsartan, which suggested that endogenous angiotensin may be involved in the response to opiorphin. Interestingly, the effect of opiorphin on water intake was increased in both fasted and freely feeding mice, which was completely blocked by captopril and valsartan. Furthermore, naloxone did not modify the effect of opiorphin on water intake. All together, the food and water intake effects of opiorphin may be due to the protection of the endogenous angiotensin and opioid peptides from degradation by NEP or APN.


Assuntos
Ingestão de Líquidos , Ingestão de Alimentos , Oligopeptídeos/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Captopril/farmacologia , Escuridão , Jejum , Humanos , Injeções Intraventriculares , Masculino , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Oligopeptídeos/farmacologia , Sistema Renina-Angiotensina/fisiologia , Proteínas e Peptídeos Salivares/farmacologia , Valsartana/farmacologia
7.
Eur J Pharmacol ; 749: 32-8, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25460028

RESUMO

The present study was performed to investigate the peripheral cardiovascular effects of opiorphin in anesthetized rats. Intravenous (i.v.) injection of opiorphin (50-500nmol/kg) caused marked dose-dependent increase in blood pressure and heart rate. The pressor and tachycardic responses induced by opiorphin (300nmol/kg, i.v.) were significantly decreased by pretreatment with angiotensin-converting enzyme inhibitor captopril or angiotensin II type 1 (AT1) receptor antagonist valsartan, which suggested that endogenous angiotensin may be involved in the response to opiorphin. Pretreatment with α-adrenoreceptor antagonist phentolamine and ß-adrenoceptor antagonist propranolol respectively attenuated the pressor response induced by opiorphin. Propranolol, but not phentolamine, inhibited the tachycardic response. Moreover, reserpine blocked both responses to opiorphin. These findings indicated that the effects of opiorphin to increase blood pressure and heart rate might be due to the stimulation of sympathetic ganglia. Additionally, studies with bilaterally adrenalectomized rats showed that adrenal medulla may be involved in the cardiovascular regulation of opiorphin. In addition, pretreatment with nonselective opioid receptor antagonist naloxone did not modify the cardiovascular responses to opiorphin, suggesting that the effects of opiorphin were not related to the opioid system. Furthermore, radioimmunoassay (RIA) showed that opiorphin significantly increased endogenous levels of angiotensin II and angiotensin III. In summary, all the results indicate that the cardiovascular effects induced by opiorphin are mediated through the renin-angiotensin system (RAS), the sympathetic ganglia and adrenal medulla, but not the opioid system.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Oligopeptídeos/farmacologia , Proteínas e Peptídeos Salivares/farmacologia , Inibidores da Captação Adrenérgica/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Captopril/farmacologia , Humanos , Masculino , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Fentolamina/farmacologia , Propranolol/farmacologia , Ratos Sprague-Dawley , Sistema Renina-Angiotensina/efeitos dos fármacos , Reserpina/farmacologia , Tetrazóis/farmacologia , Valina/análogos & derivados , Valina/farmacologia , Valsartana
8.
Peptides ; 55: 47-51, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24486428

RESUMO

Human opiorphin is a recently identified endogenous pentapeptide, encoded by ProL1 multigenes family that contributes to cardiovascular modulation. The aim of this study was to evaluate the effect of opiorphin through intravenous injection (i.v.) on mean arterial pressure (MAP) regulation. To investigate the bioactivity of opiorphin, a rat cannulation model was developed for MAP measurement and blood sampling. In our present study, opiorphin (200-700 nmol/kg) increased MAP in dose-related and time-dependent manner in conscious rats, which associated highly with the elevation of angiotensin II (AngII) levels in serum. Furthermore, the MAP elevation induced by opiorphin was completely blocked by AngII receptor antagonist valsartan and partially attenuated by angiotensin-converting enzyme inhibitor captopril. Finally, we tested the effect of opiorphin in hypoxia condition, which exhibited that opiorphin reversed hypoxia induced hypotension in conscious rats. Taken together, these results indicated that opiorphin may play an important role in the modulation of blood pressure through AngII dependent pathway, which may help future development of potent clinical therapeutics for emergency treatment.


Assuntos
Oligopeptídeos/fisiologia , Sistema Renina-Angiotensina , Proteínas e Peptídeos Salivares/fisiologia , Angiotensina II/sangue , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea , Captopril/farmacologia , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Hipóxia/complicações , Hipóxia/fisiopatologia , Masculino , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Ratos Wistar , Proteínas e Peptídeos Salivares/farmacologia , Proteínas e Peptídeos Salivares/uso terapêutico , Tetrazóis/farmacologia , Valina/análogos & derivados , Valina/farmacologia , Valsartana
9.
ACS Appl Mater Interfaces ; 5(15): 7014-24, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23815399

RESUMO

We develop paclitaxel (PTX) and magnetic nanoparticles (MNPs) coencapsulated, surface charge-switchable, thermosensitive poly(d,l-lactic-co-glycolic acid)-l-lysine-d-galactose (PTX-MNP-PLGA-Lys-Gal) NPs for the controlled release of the anticancer drug. The novel dual signal-responsive nanovehicle is formulated to shield off target at pH 7.4 but bind avidly to tumor cells in acidity, alleviating toxicity and side effects of the drug to normal tissues. The mechanism involves pH-sensitive NPs surface charge switching by the deblocking process of galactose molecules followed by protonation of ε-NH2 in lysine residue at acidic pH. Magnetic hyperthermia under near infrared (NIR) irradiation induced the contraction of PTX-MNP-PLGA-Lys-Gal NPs and, in turn, triggered burst release of PTX. Transmission electron microscopy (TEM), fluorescence microscope analyses, Fourier transform infrared (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), dynamic light scattering (DLS), and ξ-potential analyses were performed to characterize physicochemical properties of the as-prepared NPs. The size range of the globule PTX-MNP-PLGA-Lys-Gal NPs after being prescreened was from 130 to 150 nm under simulated physiological medium. The high encapsulation efficiencies of MNPs and PTX were obtained, reaching 85 and 78 wt % for PTX-MNP-PLGA-Lys-Gal NPs, respectively. The tumor inhibitory rate of 78.8% reflected that the resulting NPs could be promising to treat cancer by specific binding and targeting release drug to tumor.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas/química , Neoplasias/tratamento farmacológico , Paclitaxel/administração & dosagem , Linhagem Celular Tumoral , Físico-Química/métodos , Eritrócitos/citologia , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Lisina/química , Magnetismo , Nanopartículas Metálicas/química , Microscopia Eletrônica de Transmissão/métodos , Ácido Oleico/química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Propriedades de Superfície , Difração de Raios X
10.
Neurosci Lett ; 489(2): 131-5, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21145938

RESUMO

In the present study, we investigated the antidepressive activity of opiorphin with central administration in the forced swim test in mice. Intracerebroventricular (i.c.v.) administration of opiorphin (1-6 µg/mouse) dose-dependently decreased the immobility time, which was reversed by nonselective opioid receptor antagonist naloxone, δ-selective naltrindole and µ-selective ß-FNA. The data suggested that central administration of opiorphin produced an antidepressant-like effect by activating both µ and δ opioid receptors indirectly. In order to eliminate the possibility of a false-positive result in the forced swim test, locomotor activity was checked in both non-habituated and habituated mice. Opiorphin had no influence on non-habituated mice, though had weak effect on habituated mice. In addition, mice treated with opiorphin did not display any convulsive behaviors.


Assuntos
Antidepressivos/farmacologia , Atividade Motora/efeitos dos fármacos , Oligopeptídeos/farmacologia , Receptores Opioides delta/fisiologia , Receptores Opioides mu/fisiologia , Proteínas e Peptídeos Salivares/farmacologia , Animais , Antidepressivos/administração & dosagem , Relação Dose-Resposta a Droga , Habituação Psicofisiológica , Humanos , Injeções Intraventriculares , Masculino , Camundongos , Naloxona/farmacologia , Naltrexona/análogos & derivados , Naltrexona/farmacologia , Oligopeptídeos/administração & dosagem , Receptores Opioides delta/antagonistas & inibidores , Receptores Opioides mu/antagonistas & inibidores , Proteínas e Peptídeos Salivares/administração & dosagem , Transdução de Sinais
11.
Peptides ; 30(7): 1348-54, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19442408

RESUMO

In the present study, we investigated the effects of human opiorphin on colonic motility and nociception in mice. In in vitro bioassay, opiorphin (10(-6) to 10(-4)M) caused colonic contraction in a concentration-dependent manner, which was completely blocked by naloxone and partially attenuated by beta-funaltrexamine and naltrindole. Moreover, opiorphin (10(-4)M) significantly enhanced the contractile response induced by Met-enkephalin. The data suggested that the effect of opiorphin on colonic contraction may be due to the protection of enkephalins. In in vivo bioassay, intracerebroventricular (i.c.v.) administration of opiorphin (1.25-10 microg/kg) dose- and time-dependently induced potent analgesic effect (ED(50)=3.22 microg/kg). This effect was fully blocked by naloxone and significantly inhibited by co-injection (i.c.v.) with beta-funaltrexamine or naltrindole, but not by nor-binaltorphimine, indicating the involvement of both mu- and delta-opioid receptors in the analgesic response evoked by opiorphin. In addition, i.c.v. administration of 5 microg/kg opiorphin produced the comparative effect as 10 microg/kg morphine on the analgesia, suggesting that opiorphin displayed more potent analgesic effect than that induced by morphine.


Assuntos
Analgésicos/farmacologia , Colo/efeitos dos fármacos , Motilidade Gastrointestinal/efeitos dos fármacos , Oligopeptídeos/farmacologia , Proteínas e Peptídeos Salivares/farmacologia , Animais , Humanos , Masculino , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Medição da Dor
12.
Vascul Pharmacol ; 51(2-3): 78-83, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19345746

RESUMO

Caffeic acid phenethyl ester (CAPE) is a naturally occurring compound isolated from honeybee propolis whose cardiovascular properties remain uncertain. The purpose of this study was to investigate the possible mechanisms of CAPE-induced vasorelaxation in porcine coronary artery rings. It was found that both the quiescent and precontracted coronary artery ring segments were relaxed by CAPE (10(-7)-10(-)(4) M). N(omega)-nitro-l-arginine (L-NNA), methylene blue and removal of endothelium significantly attenuated CAPE-induced relaxation of both quiescent and precontracted artery rings. This relaxing effect of CAPE on coronary arteries was also significantly reduced by propranolol, and SQ22536, but not by indomethacin. In addition, the dose-response curves of KCl (2.5-100 mM) and CaCl(2) (10(-5)-10(-2) M) were displaced downwards in the presence of CAPE. These results suggest that the relaxant effect of CAPE on porcine coronary artery rings might involve the action of nitric oxide (NO) and adrenergic beta-receptor, together with their second messenger, cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), respectively, but not involve the synthesis of prostaglandin.


Assuntos
Ácidos Cafeicos/farmacologia , Vasos Coronários/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Álcool Feniletílico/análogos & derivados , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Inibidores de Adenilil Ciclases , Antagonistas Adrenérgicos beta/farmacologia , Análise de Variância , Animais , Ácidos Cafeicos/administração & dosagem , Sinalização do Cálcio , Doença da Artéria Coronariana/tratamento farmacológico , Vasos Coronários/fisiologia , GMP Cíclico/antagonistas & inibidores , Inibidores de Ciclo-Oxigenase/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiologia , Técnicas In Vitro , Músculo Liso Vascular/fisiologia , Óxido Nítrico Sintase/antagonistas & inibidores , Álcool Feniletílico/administração & dosagem , Álcool Feniletílico/farmacologia , Suínos , Vasoconstritores/farmacologia , Vasodilatadores/administração & dosagem
13.
Eur J Pharmacol ; 569(1-2): 119-25, 2007 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-17560993

RESUMO

Rat and mouse hemokinin-1(r/m hemokinin-1) is a recently described member of the tachykinin family whose cardiovascular functions are not fully understood. In this study, we investigated the mechanisms of the relaxing response induced by r/m hemokinin-1 in isolated porcine coronary arteries by using a specific antagonist of tachykinin NK(1) receptor (SR140333), a nitric oxide synthase inhibitor N(omega)-nitro-L-arginine (L-NNA), and 1H-[1,2,4] Oxadiazolo [4,3-a] quinoxalin-1-one (ODQ), a blocker of cGMP production. r/m Hemokinin-1 (10(-12)-10(-6 )M) evoked a marked endothelium-dependent vasodilatation (E(max)=121.12+/-10.6% and 91.79+/-2.39% in 10(-6) M PGF(2)alpha and 30 mM KCl precontracted arterial rings, respectively) of coronary arteries mediated by activation of endothelial tachykinin NK(1) receptors. Two components contributed to this r/m hemokinin-1-elicited vasodilatation, the first of which was endothelium-derived hyperpolarizing factor (EDHF), which played a major role. This EDHF was identified as a potassium current through certain kinds of potassium channels on the endothelial cell membrane of porcine coronary arteries. Specific antagonists of Ca(2+)-activated K(+) channels (dequalinium and clotrimazole) did not have an inhibitory effect on the r/m hemokinin-1-induced vasodilatation, whereas they did on the substance P-induced vasodilatation. When potassium ion efflux was impaired by a high K(+) concentration (30 mM) or removal of K(+) from the surroundings, NO synthesis was triggered by r/m hemokinin-1 to produce an equivalent EDHF (K(+))-independent vasorelaxation as a compensatory mechanism.


Assuntos
Vasos Coronários/efeitos dos fármacos , Precursores de Proteínas/farmacologia , Taquicininas/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Anti-Infecciosos Locais/farmacologia , Clotrimazol/farmacologia , Vasos Coronários/fisiologia , Dequalínio/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiologia , Inibidores Enzimáticos/farmacologia , Técnicas In Vitro , Camundongos , Antagonistas dos Receptores de Neurocinina-1 , Neurotransmissores/farmacologia , Óxido Nítrico/fisiologia , Nitroarginina/farmacologia , Oxidiazóis/farmacologia , Piperidinas/farmacologia , Potássio/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Quinoxalinas/farmacologia , Quinuclidinas/farmacologia , Ratos , Receptores da Neurocinina-1/fisiologia , Receptores de Prostaglandina/fisiologia , Substância P/antagonistas & inibidores , Substância P/farmacologia , Suínos , Tetraetilamônio/farmacologia , Vasodilatação/fisiologia
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