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1.
Photosynth Res ; 159(2-3): 153-164, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37204684

RESUMO

Different light spectra from light-emitting diodes (LEDs) trigger species-specific adaptive responses in plants. We exposed Artemisia argyi (A. argyi) to four LED spectra: white (the control group), monochromatic red light (R), monochromatic blue light (B), or a mixture of R and B light of photon flux density ratio is 3 (RB), with equivalent photoperiod (14 h) and light intensity (160 µmol s-1 m-2). R light accelerated photomorphogenesis but decreased biomass, while B light significantly increased leaf area and short-term exposure (7 days) to B light increased total phenols and flavonoids. HPLC identified chlorogenic acid, 3,5-dicaffeoylquinic acid, gallic acid, jaceosidin, eupatilin, and taxol compounds, with RB and R light significantly accumulating chlorogenic acid, 3,5-dicaffeoylquinic acid, and gallic acid, and B light promoting jaceosidin, eupatilin, and taxol. OJIP measurements showed that B light had the least effect on the effective quantum yield ΦPSII, with higher rETR(II), Fv/Fm, qL and PIabs, followed by RB light. R light led to faster photomorphology but lower biomass than RB and B lights and produced the most inadaptability, as shown by reduced ΦPSII and enlarged ΦNPQ and ΦNO. Overall, short-term B light promoted secondary metabolite production while maintaining effective quantum yield and less energy dissipation.


Assuntos
Artemisia , Ácido Clorogênico/análogos & derivados , Artemisia/metabolismo , Fluorescência , Ácido Gálico , Clorofila/metabolismo , Paclitaxel
2.
Nanotechnology ; 32(2): 025401, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33055362

RESUMO

Potassium-ion batteries (KIBs) are emerging as attractive alternatives to lithium-ion batteries for the large scale energy storage and conversion systems, in view of the natural abundance and low cost of potassium resources. However, the lack of applicable anodes for reversible accommodation to the large K+ limits the application of KIBs. Herein, porous Sb-graphene-carbon (Sb-G-C) nanofibers are fabricated via a scalable and facile electrospinning approach. As an attempt, the nanofibers weaving into flexible mats are introduced as binder-free anode materials of KIBs, presenting a great cycle life (204.95 mAh g-1 after 100 cycles at 100 mA g-1), as well as the excellent rate capability (120.83 mAh g-1 at 1 A g-1). The superior performances of the Sb-G-C anodes can be derived from the dispersed graphene, which offers enhanced tolerance to the volume change and promotes the electron transportation, accounting for the outstanding cyclability and rate capability. Furthermore, the extrinsic pseudocapacitance created from the 1D porous nanostructure of the Sb-G-C also boosts the K+ storage capacity. The presented results may pave a new pathway for future high-performance KIBs.

3.
Nanotechnology ; 29(37): 375702, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-29926805

RESUMO

Potassium-ion batteries (KIBs) are considered as attractive alternatives to commercial lithium-ion batteries. However, the lack of suitable electrodes to host large K+ for rapid as well as reversible insertion/extraction hinders the developments of KIBs. As an attempt, the phosphoric acid doped SnO2-graphene-carbon (P-SGC) nanofibers synthesized with a facile electrospinning method are introduced and applied as anode materials for KIBs. The P-SGC anodes present a reversible capacity of 285.9 mAh g-1 over 60 cycles at the current density of 100 mA g-1, and the high rate capacity of 208.53 mAh g-1 at 1 A g-1 as well. Emphasis is placed on enhancing the electrochemical properties of the SGC nanofibers by phosphoric acid modification through more active sites and higher electrical conductivity, accounting for improved K+ diffusion kinetics. Meanwhile, the coated carbon matrix and dispersive graphene buffer the structural changes and protect the active materials from destruction, leading to the good structural stability. With the presented results, these P-SGC nanofibers show attractive potential for future energy storage application of KIBs.

4.
J Nat Prod ; 80(8): 2199-2203, 2017 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-28749670

RESUMO

Six new azaphilone derivatives, talaraculones A-F (1-6), together with five known analogues (7-11), were obtained from the saline soil-derived fungus Talaromyces aculeatus. The absolute configurations of 1 and 6 were assigned by quantum chemical calculations of the electronic circular dichroism (ECD) spectra. Compounds 1 and 5 represent the first reported azaphilone derivatives with a C4 aliphatic side chain and a methylal group at C-3, respectively. Talaraculones A and B (1 and 2) exhibited stronger inhibitory activity against α-glucosidase than the positive control acarbose (IC50 = 101.5 µM), with IC50 values of 78.6 and 22.9 µM, respectively.


Assuntos
Acarbose/química , Benzopiranos/isolamento & purificação , Benzopiranos/farmacologia , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/farmacologia , Talaromyces/química , alfa-Glucosidases/química , Benzopiranos/química , Dicroísmo Circular , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Pigmentos Biológicos/química , alfa-Glucosidases/metabolismo
5.
Analyst ; 140(13): 4687-93, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26030158

RESUMO

In this paper, we report a highly selective and sensitive ratiometric NIR fluorescent probe that can be used for real-time detection of the biologically important hypochlorite with colorimetric and significant NIR fluorescent turn-on signal changes at NIR excitation wavelength. In addition, experiments showed that this probe can be applied to detect hypochlorite in tap water, serum samples, and living cells with low cytotoxicity.


Assuntos
Colorimetria/métodos , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Água/química , Animais , Sobrevivência Celular , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Ácido Hipocloroso/sangue , Camundongos , Células RAW 264.7
6.
Anal Chem ; 86(17): 8835-41, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25102423

RESUMO

The development of probes for rapid, selective, and sensitive detection of the highly toxic thiophenols is of great importance in both environmental and biological science. Despite the appealing advantages of near-infrared (NIR) fluorescent detection, no NIR fluorescent probes have been reported for thiophenols to date. Using the chemical properties of thiophenols that are able to cleave sulfonamide selectively and efficiently under mild conditions, we herein report a dicyanomethylene-benzopyran (DCMB)-based NIR fluorescent probe for thiophenols. This probe features remarkable large Stokes shift and shows a rapid, highly selective, and sensitive detection process for thiophenols with significant NIR fluorescent turn-on responses. The potential applications of this new NIR fluorescent probe were demonstrated by the quantitative detection of thiophenol in real water samples and by fluorescent imaging of thiophenol in living cells.


Assuntos
Técnicas de Química Analítica/instrumentação , Corantes Fluorescentes/química , Fenóis/análise , Espectroscopia de Luz Próxima ao Infravermelho , Compostos de Sulfidrila/análise , Benzopiranos/química , Água Doce/química , Células HeLa , Humanos , Microscopia de Fluorescência , Nitrilas/química
7.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 30(2): 157-60, 2013 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-23568725

RESUMO

OBJECTIVE: To investigate clinical and molecule genetics features of four Ph-positive leukemia patients characterized by pericentric inv(9)(p22q34) with the der(9)t(9;22)(q34;q11). METHODS: Cytogenetic analysis was carried out on bone marrow directly or after short-period culture. R banding was used for karyotype analysis. BCR/ABL fusion gene was detected with interphase fluorescence in situ hybridization (FISH), and chromosome painting was carried out using specific probes. RT-PCR was used to detect BCR/ABL chimeric transcripts. RESULTS: One patient with acute myeloid leukemia (AML) presented three clones, which included one with a normal karyotype, one with t(9;22)(q34;q11), and one with inv(9)(p22q34) involving the der(9)t(9;22) and additional t(8;12)(q12;p11). The inv(9)(p22q34) has always co-occurred with der(9)t(9;22)(q34;q11) accompanied by der(22)t(9;22)(q34;q11) in all metaphases from the three patients with chronic myeloid leukemia (CML). B3a2 transcript was detected in all patients by RT-PCR. Inv(9)(p22q34) was found in both CML and AML, and was associated with poor prognosis. CONCLUSION: Inv(9)(p22q34) is a novel, rare, but recurrent secondary chromosomal abnormality for Ph-positive leukemia. Leukemia with der(9)t(9;22) and inv(9)(p22q34) has unique clinical and laboratory characteristics.


Assuntos
Inversão Cromossômica , Cromossomos Humanos Par 22 , Cromossomos Humanos Par 9 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Translocação Genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Nanomicro Lett ; 12(1): 39, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-34138251

RESUMO

Sodium-ion batteries (SIBs) are considered to be attractive candidates for large-scale energy storage systems because of their rich earth abundance and consistent performance. However, there are still challenges in developing desirable anode materials that can accommodate rapid and stable insertion/extraction of Na+ and can exhibit excellent electrochemical performance. Herein, the self-assembled hairball-like VS4 as anodes of SIBs exhibits high discharge capacity (660 and 589 mAh g-1 at 1 and 3 A g-1, respectively) and excellent rate property (about 100% retention at 10 and 20 A g-1 after 1000 cycles) at room temperature. Moreover, the VS4 can also exhibit 591 mAh g-1 at 1 A g-1 after 600 cycles at 0 °C. An unlike traditional mechanism of VS4 for Na+ storage was proposed according to the dates of ex situ characterization, cyclic voltammetry, and electrochemical kinetic analysis. The capacities of the final stabilization stage are provided by the reactions of reversible transformation between Na2S and S, which were considered the reaction mechanisms of Na-S batteries. This work can provide a basis for the synthesis and application of sulfur-rich compounds in fields of batteries, semiconductor devices, and catalysts.

9.
ACS Nano ; 14(8): 9626-9636, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32786231

RESUMO

Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) have attracted much attention owing to the inexpensive Na/K metal and satisfactory performance. Currently, there are still difficulties in research anode materials that can insert/extract Na/K ions quickly and stably. Herein, the sulfur-rich (NH4)2Mo3S13 is proposed as the anode for SIBs/PIBs and is obtained by a hydrothermal method. The sulfur-rich (NH4)2Mo3S13 with a three-dimensional structure shows a high capacity and long lifespans for Na+ (at 10 A g-1 the capacity of 165.2 mAh g-1 after 1100 cycles) and K+ (120.7 mAh g-1 at 1 A g-1 retained after 500 cycles) storage. In addition, the (NH4)2Mo3S13 electrode exhibits excellent electrochemical performance at low temperatures (0 °C). The mechanism of Na+ storage in (NH4)2Mo3S13 can be innovatively revealed through the combined use of electrochemical kinetic analysis and a series of ex situ characterization tests. It is believed that the present work identifies (NH4)2Mo3S13 as a promising anode for the SIBs/PIBs and will be of broad interest in research on engineering sulfur-rich transition metal sulfide and on energy storage devices.

10.
Nanoscale ; 12(10): 6037-6046, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32129406

RESUMO

Efficient spatial charge separation and transfer that are critical factors for solar energy conversion primarily depend on the energetic alignment of the band edges at interfaces in heterojunctions. Herein, we first report that constructing a 0D/0D type-II(T-II)/T-II heterojunction is an effective strategy to ingeniously achieve long-range charge separation by taking a ternary heterojunction of TiO2 and graphitic carbon nitride (g-C3N4) as a proof-of-concept. Incorporating g-C3N4 quantum dots (QCN), as the third component, into the commercial P25 composed of anatase (a-TiO2) and rutile (r-TiO2) can be realized via simply mixing the commercially available Degussa P25 and QCN solution followed by heat treatment. The strong coupling and matching band structures among a-TiO2, r-TiO2 and QCN result in the construction of novel T-II/T-II heterojunctions, which would promote the spatial separation and transfer of photogenerated electrons and holes. Moreover, QCN plays a key role in reinforcing light absorption. Particularly, the unique 0D/0D architecture possesses the advantages of abundant active sites for the photocatalytic reaction. As a result, the optimized QCN/a-TiO2/r-TiO2 heterojunctions exhibit enhanced photocatalytic H2 and O2 evolution, especially the hydrogen evolution rate (49.3 µmol h-1) is 11.7 times that of bare P25 under visible light irradiation, and sufficient catalytic stability as evidenced by the recycling experiments. The remarkably enhanced photocatalytic activity can be attributed to the synergistic effects of the energy level alignment at interfaces, the dimensionality and component of the heterojunctions. This work provides a stepping stone towards the design of novel heterojunctions for photocatalytic water splitting.

11.
Nat Prod Res ; 31(1): 99-103, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27498615

RESUMO

One new quinolinone, 7-hydroxy-3-methoxyviridicatin (1), along with eight known compounds (2-9) was isolated from the fungus Myrothecium verrucaria, which was collected from lake water of Chenghai, Yunnan Province, China. Their structures were elucidated by detailed analysis of spectroscopic data and comparison with related known compounds. Compounds 1 and 2 exhibited weak antibacterial activity. To the best of our knowledge, this is the first report on quinolinones (1-4) as the secondary metabolites of M. verrucaria.


Assuntos
Hypocreales/química , Quinolinas/química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , China , Água Doce/microbiologia , Lagos/microbiologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Quinolinas/farmacologia , Quinolonas , Espectrometria de Massas por Ionização por Electrospray , Microbiologia da Água
12.
Cardiovasc Res ; 53(4): 963-70, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11922906

RESUMO

OBJECTIVE: Importance of endothelin in mediating the chronic renal alterations of chronic heart failure was studied in rats chronically treated with bosentan after myocardial infarction. METHODS: Rats were subjected to coronary artery ligation and were treated for 8 weeks with placebo or bosentan, a dual ET(A) and ET(B) receptor antagonist, (approximately 100 mg/kg/day) as food admix. Sham-operated rats served as normal controls. Cardiac and renal functions were measured at the end of 8-week treatment. RESULTS: Bosentan significantly reduced the elevated left ventricular end-diastolic pressure (from 26.6+/-3.3 to 11.4+/-2.2 mmHg, P<0.001) and the increased heart-to-body-weight ratio seen in untreated rats with myocardial infarction. Bosentan prevented the marked increase in renal vascular resistance (bosentan, 7.7+/-0.6; untreated, 15.6+/-2.5 mmHg/ml/min; P<0.001). This led to a significant increase in renal plasma flow resulting in a decrease in filtration fraction. Bosentan furthermore increased urinary sodium excretion. CONCLUSIONS: Prolonged ET receptor blockade in rats with myocardial infarction has chronic renal vasodilatory effect and improves renal sodium excretory function. Thus, dual ET antagonists such as bosentan might be useful in the treatment of the progressive renal failure associated with human chronic heart failure.


Assuntos
Anti-Hipertensivos/farmacologia , Antagonistas dos Receptores de Endotelina , Insuficiência Cardíaca/fisiopatologia , Natriurese/efeitos dos fármacos , Circulação Renal/efeitos dos fármacos , Sulfonamidas/farmacologia , Animais , Bosentana , Esquema de Medicação , Taxa de Filtração Glomerular/efeitos dos fármacos , Insuficiência Cardíaca/etiologia , Hemodinâmica/efeitos dos fármacos , Masculino , Infarto do Miocárdio/complicações , Ratos , Ratos Wistar , Vasoconstrição/efeitos dos fármacos
13.
Biosens Bioelectron ; 68: 316-321, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25597530

RESUMO

A readily available naphthofluorescein-based near-infrared (NIR) fluorescent probe was reported for rapid, colorimetric and NIR fluorescent turn-on detection of cysteine (Cys) with high selectivity and sensitivity over various analytes including the similar structured homocysteine (Hcy) and glutathione (GSH). This probe was successfully applied to bioimage intracellular Cys in living cells with low cytotoxicity.


Assuntos
Cisteína/análise , Fluoresceínas/química , Corantes Fluorescentes/química , Imagem Óptica , Técnicas Biossensoriais , Sobrevivência Celular , Colorimetria , Células HeLa , Humanos
14.
Environ Sci Pollut Res Int ; 22(21): 17171-81, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26139408

RESUMO

The objectives of this work are to track the contamination levels, distribution characteristics, and sources of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in atmospheric particulate matter (APM) of Northern China and to provide more comprehensive and fundamental data for risk assessment of organochlorine contaminants (OCs) in environments. Samples were extracted and purified by the microwave-assisted extraction and solid-phase extraction system, respectively. PCBs and OCPs were analyzed by gas chromatograph-mass spectrometer. The concentrations of ΣPCBs and ΣOCPs ranged from 0.73 to 112.65 ng/g and 0.14 to 34.73 ng/g, respectively. PCBs in atmospheric particulates collected from Shijiazhuang City had the highest concentration, whereas OCP congeners were at the relatively low levels. However, the highest concentration of OCPs occurred in Yongning City. The principal component analysis indicated that the predominant compositions of PCBs in most of samples were tetrachlorobiphenyl (Tetra-CB), pentachlorobiphenyl (Penta-CB), hexachlorobiphenyl (Hexa-CB), and heptachlorbiphenyl (Hepta-CB), while hexachlorocyclohexanes (HCHs), DDTs, chlordanes, and endosulfans were the dominant components of OCPs, which was attributed to their application characteristics. OCs in those particles were further used to assess a potential cancer risk to humans via ingestion, dermal contact, and inhalation. Cancer risk was evaluated in airborne particles caused by PCBs and OCPs. TEQPCBs values suggested that the representative areas were subject to different pollution degrees. However, the pollution of OCPs in certain areas should be a concern due to 41.6% of the high risk, which could pose a potential risk to organisms.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Material Particulado/análise , Praguicidas/análise , Bifenilos Policlorados/análise , China , Clordano/análise , Cromatografia Gasosa-Espectrometria de Massas , Hexaclorocicloexano/análise , Humanos , Medição de Risco , Extração em Fase Sólida
15.
Zhonghua Yi Xue Za Zhi ; 84(3): 248-52, 2004 Feb 02.
Artigo em Chinês | MEDLINE | ID: mdl-15059549

RESUMO

OBJECTIVE: To investigate the interrelation between endothelin-1 (ET-1) and angiotensin II (AngII) in kidney tissue of rats with diabetic nephropathy. METHODS: Wistar rats were performed a removal operation of right kidney. Two weeks later the uninephrectomized rats were given intravenous injection of streptozotocin (STZ, 35 mg/kg). The diabetic rats were randomly divided into the following four groups: DM + bos group (bosentan 100 mg/kg/d by gavage); DM + ena group (enalapril 10 mg/kg/d by gavage); DM + bos + ena group (the same doses of both bosentan and enalapril by gavage); DM + veh group (only buffer by gavage). Besides, uninephrectomized rats without STZ injection were assigned as control group. Each group consisted of 6 rats. Twenty weeks later, they were sacrificed and left kidney of each rat was harvested respectively. The mRNA expression of angiotensinogen (Ao), angiotensin type 1 receptor (AT1R), preproendothelin-1 and endothelin A receptor (ETaR), and the protein expression of AngII, AT1R, ET-1 and ETaR in kidney tissue were semi-quantitatively detected with reverse transcription- polymerase chain reaction and immunohistochemical staining respectively. RESULTS: In the diabetic group without treatment (DM + veh group), the expression of Ao (AII), AT1R and ET-AR was significantly up-regulated (1.25, 1.94 and 2.56-folds in mRNA respectively, 2.52, 3.84 and 3.30-folds in protein respectively, P < 0.01 or P < 0.05) compared with control group. In three treatment groups, i.e. DM + bos group, DM + ena group and DM + bos + ena group, the up-regulated expression of Ao (AII), AT1R and ET-AR was significantly attenuated (-38.2% to -54.8% in mRNA and -55.3% to -69.7% in protein, P < 0.05 or P < 0.01) compared with DM group. The inhibitory rates among these three treatment groups had no significant difference (P > 0.05). In this study, the expression of preproendothelin-1 mRNA and ET-1 protein was not significantly changed among all groups (P > 0.05). CONCLUSION: Either endothelin receptor antagonist or ACE inhibitor can significantly inhibit the expression of AngII, AT1R and ETaR in kidney tissue of diabetic rats, which suggest that there are close relationship and cross action between ET-1 and AngII.


Assuntos
Angiotensina II/fisiologia , Nefropatias Diabéticas/metabolismo , Endotelina-1/fisiologia , Angiotensina II/genética , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Endotelina-1/análise , Masculino , RNA Mensageiro/análise , Ratos , Ratos Wistar , Receptor Tipo 1 de Angiotensina/genética , Receptor de Endotelina A/genética
16.
Chem Commun (Camb) ; 50(90): 14002-5, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25265894

RESUMO

A new colorimetric and fluorescent probe was reported, which can be used in a very low dosage (<20 nM) for rapid, highly selective and sensitive detection of biothiols.


Assuntos
Corantes Fluorescentes/química , Imagem Molecular , Compostos de Sulfidrila/análise , Colorimetria , Células HeLa , Humanos , Estrutura Molecular
17.
Chem Commun (Camb) ; 50(65): 9185-7, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-24995969

RESUMO

We report herein a new approach, which combines fast nucleophilic addition of H2S to an aldehyde group and the subsequent intramolecular thiolysis of dinitrophenyl ether, and can be used to develop efficient and effective H2S probes.


Assuntos
Aldeídos/química , Éteres/química , Sulfeto de Hidrogênio/análise , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Células HeLa , Humanos
18.
ACS Appl Mater Interfaces ; 6(20): 17543-50, 2014 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-25253409

RESUMO

We report a simple and readily available fluorescent probe for rapid, specific, and ratiometric fluorescent detection of the biologically important cysteine (Cys). This probe uses a visible-light excitable excited-state intramolecular proton transfer (ESIPT) dye (4'-dimethylamino-3-hydroxyflavone) as the fluorophore and an acrylate group as the ESIPT blocking agent as well as the recognition unit. Cleavage of the acrylate moiety can be achieved specifically and rapidly by Cys in aqueous solution under mild conditions, which leads to restore the ESIPT process and enables the probe to show a rapid, ratiometric fluorescent detection process for Cys with high selectivity over various analytes, including homocysteine (Hcy) and glutathione (GSH). The detection limit of this probe for Cys was found to be ∼0.2 µM and bioimaging of intracellular Cys by this probe was successfully applied in living cells, indicating that this probe holds great potential for biological applications.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Técnicas de Sonda Molecular , Cisteína/química , Corantes Fluorescentes/síntese química , Glutationa/química , Células HeLa , Homocisteína/química , Humanos , Cinética , Espectrometria de Fluorescência
19.
J Pharmacol Exp Ther ; 316(3): 1115-21, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16267137

RESUMO

Urotensin-II (U-II) is a cyclic peptide that acts through a specific G-protein-coupled receptor, UT receptor. Urotensin-II and UT receptors have been described in pancreas and kidney, but their function is not well understood. We studied the effects of chronic treatment of diabetic rats with the orally active selective U-II receptor antagonist palosuran. Streptozotocin treatment causes pancreatic beta-cell destruction and leads to the development of hyperglycemia, dyslipidemia, and renal dysfunction. Long-term treatment of streptozotocin-induced diabetic rats with palosuran improved survival, increased insulin, and slowed the increase in glycemia, glycosylated hemoglobin, and serum lipids. Furthermore, palosuran increased renal blood flow and delayed the development of proteinuria and renal damage. The U-II system is unique in that it plays a role both in insulin secretion and in the renal complications of diabetes. Urotensin receptor antagonism might be a new therapeutic approach for the treatment of diabetes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Rim/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Quinolinas/uso terapêutico , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Ureia/análogos & derivados , Albuminúria/tratamento farmacológico , Animais , Glicemia/análise , Diabetes Mellitus Experimental/fisiopatologia , Rim/patologia , Rim/fisiopatologia , Masculino , Pâncreas/patologia , Pâncreas/fisiopatologia , Ratos , Ratos Wistar , Estreptozocina , Ureia/uso terapêutico
20.
J Cardiovasc Pharmacol ; 42(1): 48-54, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12827026

RESUMO

Diabetic nephropathy is associated with enhanced renal synthesis of endothelin (ET)-1. The goal of this study was to investigate the effects of dual ET receptor antagonism in the early phase (2 months) and in the late phase (5 months) of diabetic nephropathy in rats, and to compare this approach to angiotensin-converting enzyme inhibition. Four groups of uninephrectomized streptozotocin-induced diabetic rats were assigned to receive orally vehicle, bosentan, enalapril, or their combination. A fifth group consisted of nondiabetic, uninephrectomized rats. At 2 weeks, untreated diabetic rats exhibited increased glomerular filtration rate and renal plasma flow. Bosentan, enalapril, and the combination all prevented hyperfiltration and hyperperfusion. By 5 months, diabetic rats developed marked increases in mean arterial pressure and renal vascular resistance, progressive proteinuria, and renal structural damage with glomerular sclerosis and hypertrophy. Bosentan completely prevented the development of hypertension and renal vasoconstriction, and largely prevented the development of proteinuria and renal structural injury. The renal protective effect of bosentan was comparable to that of enalapril or the combination, although its anti-proteinuric effect was less. Clinical studies are warranted to assess whether ET receptor antagonism can have additive effects on top of ACE inhibition, the current treatment of choice in diabetic nephropathy.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Antagonistas do Receptor de Endotelina A , Taxa de Filtração Glomerular/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Pressão Sanguínea/efeitos dos fármacos , Bosentana , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/fisiopatologia , Enalapril/administração & dosagem , Enalapril/uso terapêutico , Taxa de Filtração Glomerular/fisiologia , Rim/irrigação sanguínea , Rim/metabolismo , Rim/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Sulfonamidas/administração & dosagem , Sulfonamidas/uso terapêutico , Vasoconstrição/fisiologia
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