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1.
Front Cardiovasc Med ; 9: 863248, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35498008

RESUMO

Acute myocardial infarction (AMI) is one of the most serious cardiovascular diseases worldwide. Advances in genomics have provided new ideas for the development of novel molecular biomarkers of potential clinical value for AMI. Methods: Based on microarray data from a public database, differential analysis and functional enrichment analysis were performed to identify aberrantly expressed genes in AMI and their potential functions. CIBERSORT was used for immune landscape analysis. We also obtained whole blood samples of 3 patients with AMI and performed second-generation sequencing (SGS) analysis. Weighted gene co-expression network analysis (WGCNA) and cross-tabulation analysis identified AMI-related key genes. Receiver operating characteristic (ROC) curves were used to assess the diagnostic power of key genes. Single-gene gene set enrichment analysis (GSEA) revealed the molecular mechanisms of diagnostic indicators. Results: A total of 53 AMI-related DEGs from a public database were obtained and found to be involved in immune cell activation, immune response regulation, and cardiac developmental processes. CIBERSORT confirmed that the immune microenvironment was altered between AMI and normal samples. A total of 77 hub genes were identified by WGCNA, and 754 DEGs were obtained from own SGS data. Seven diagnostic indicators of AMI were obtained, namely GZMA, NKG7, TBX21, TGFBR3, SMAD7, KLRC4, and KLRD1. The single-gene GSEA suggested that the diagnostic indicators seemed to be closely implicated in cell cycle, immune response, cardiac developmental, and functional regulatory processes. Conclusion: The present study provides new diagnostic indicators for AMI and further confirms the feasibility of the results of genome-wide gene expression analysis.

2.
Aging (Albany NY) ; 14(1): 462-476, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017318

RESUMO

Intracerebral hemorrhage (ICH) is a common neurological condition that causes severe disability and even death. Even though the mechanism is not clear, increasing evidence shows the efficacy of atorvastatin on treating ICH. In this study, we examined the impact of atorvastatin on the NOD-like receptor protein 3 (NLRP3) inflammasome and inflammatory pathways following ICH. Mouse models of ICH were established by collagenase injection in adult C57BL/6 mice. IHC mice received atorvastatin treatment 2 h after hematoma establishment. First, the changes of glial cells and neurons in the brains of ICH patients and mice were detected by immunohistochemistry and western blotting. Second, the molecular mechanisms underlying the microglial activation and neuronal loss were evaluated after the application of atorvastatin. Finally, the behavioral deficits of ICH mice without or with the treatment of atorvastatin were determined by neurological defect scores. The results demonstrated that atorvastatin significantly deactivated glial cells by reducing the expression of glial fibrillary acidic protein (GFAP), Ionized calcium binding adapter molecule 1 (Iba1), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in ICH model mice. For inflammasomes, atorvastatin also showed its efficacy by decreasing the expression of NLRP3, cleaved caspase-1, and IL-1ß in ICH mice. Moreover, atorvastatin markedly inhibited the upregulation of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88), which indicated deactivation of NLRP3 inflammasomes. By inhibiting the activities of inflammasomes in glial cells, neuronal loss was partially prevented by suppressing the apoptosis in the brains of ICH mice, protecting them from neurological defects.


Assuntos
Atorvastatina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Hemorragia Cerebral , Citocinas/genética , Citocinas/metabolismo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Neurônios/efeitos dos fármacos , Transdução de Sinais , Receptor 4 Toll-Like/genética
3.
Rev Sci Instrum ; 92(5): 054711, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243330

RESUMO

The Wuhan National High Magnetic Field Center is incorporating the flat-top pulsed magnetic field (FTPMF) into pulse gyrotrons. It will be the first chance to make a pulse-magnet gyrotron available for generating a long-pulse radiation of 100 ms or above without affecting its high operating frequency and high radiation power. However, unlike continuous wave gyrotrons, pulse gyrotrons in long-term operation have their own challenges, namely, misalignment caused by concussions, much stronger low-frequency electromagnetic interference from the pulse magnet, and inevitable explosion. This article will focus on the difficulties faced by pulse gyrotrons in years of operation, discuss the protection and restoration from failures, and, consequently, propose a fully redundant, explosion-proof, and quickly recoverable auxiliary system for long-term operation of pulse gyrotrons. This system integrates the control unit of traditional pulsed magnets and superconducting magnets so that it can be compatible with any form of gyrotron facilities. Therefore, once the FTPMF or the superconducting magnet is available, the long-pulse radiation will be obtained. Several experimental results, including the most recent explosion, show the reliability of the proposed system.

4.
Water Sci Technol ; 76(9-10): 2280-2290, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29144286

RESUMO

Coal is a porous medium and natural absorbent. It can be used for its original purpose after adsorbing organic compounds, its value does not reduce and the pollutants are recycled, and then through systemic circulation of coking wastewater zero emissions can be achieved. Thus, a novel method of industrial organic wastewater treatment using adsorption on coal is introduced. Coking coal was used as an adsorbent in batch adsorption experiments. The quinoline, indole, pyridine and phenol removal efficiencies of coal adsorption were investigated. In addition, several operating parameters which impact removal efficiency such as coking coal consumption, oscillation contact time, initial concentration and pH value were also investigated. The coking coal exhibited properties well-suited for organics' adsorption. The experimental data were fitted to Langmuir and Freundlich isotherms as well as Temkin and Redlich-Peterson (R-P) models. The Freundlich isotherm model provided reasonable models of the adsorption process. Furthermore, the purification mechanism of organic compounds' adsorption on coking coal was analysed.


Assuntos
Carvão Mineral/análise , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Coque/análise , Cinética , Compostos Orgânicos , Fenol/química , Fenóis/química , Purificação da Água/instrumentação
5.
Bioorg Med Chem Lett ; 24(21): 4958-62, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25288187

RESUMO

A series of pyrrolo-benzo-1,4-diazine analogs have been synthesized to improve the profile of the previous lead compound 1. The syntheses, structure-activity relationships, and selected pharmacokinetic data of these analogs are described. The optimization efforts allowed the identification of 33, a quinoline amide exhibiting potent Na(v)1.7 inhibitory activity and moderate selectivity over Na(v)1.5. Compound 33 displayed anti-nociceptive oral efficacy in a rat CFA inflammatory pain model at 100 mpk and in a rat spinal nerve ligation neuropathic pain model with an EC50 75 µM.


Assuntos
Analgésicos/farmacologia , Gânglios Espinais/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.7/química , Neuralgia/tratamento farmacológico , Bloqueadores dos Canais de Sódio/farmacologia , Nervos Espinhais/efeitos dos fármacos , Compostos de Espiro/farmacologia , Analgésicos/química , Animais , Estrutura Molecular , Técnicas de Patch-Clamp , Quinoxalinas/química , Ratos , Bloqueadores dos Canais de Sódio/química , Compostos de Espiro/química , Relação Estrutura-Atividade
6.
Artigo em Chinês | MEDLINE | ID: mdl-24370303

RESUMO

OBJECTIVE: To observe the clinical efficacy of tetrandrine combined with acetylcysteine effervescent tablets in the treatment of silicosis. METHODS: A total of 96 patients with silicosis were randomly divided into treatment group (49 cases) and control group (47 cases). Both groups were given routine therapy including anti-inflammatory, antitussive, and antiasthmatic drugs, and the patients in treatment group were given tetrandrine combined with acetylcysteine effervescent tablets at the same time. Tetrandrine (100 mg) was orally administrated twice a day, and there was a one-day interval between every 6 days' continuous administration; totally, there were four courses of treatment, with 3 months for each course, and there was a one-month break between each course. Acetylcysteine effervescent tablets (600 mg) were taken twice a day; each course of treatment was 12 days, and there were four courses; for the first two months, there was one course per month, and then one course every other two months for the rest of time. Clinical symptoms, pulmonary ventilation function, serum superoxide dismutase (SOD) and changes in X-ray findings were observed. RESULTS: After treatment, the treatment group had significantly increased rates of improvements in cough, expectoration, chest congestion and pain, and dyspnea compared with the control group (P < 0.05). Compared with the control group (serum SOD level: 70.466±20.261 U/ml) and the treatment group before therapy (serum SOD level: 68.182±21.414 U/ml), the treatment group after therapy had significantly increased serum SOD level (77.389±21.315 U/ml?, forced vital capacity, and forced expiratory volume in one second (P < 0.05). Eight patients in treatment group showed improvement in the chest X-ray findings of silicosis. CONCLUSION: The combination of tetrandrine and acetylcysteine effervescent tablets show some effect in the treatment of silicosis. It can be an effective option for treating silicosis as there are no other specific remedies.


Assuntos
Acetilcisteína/uso terapêutico , Benzilisoquinolinas/uso terapêutico , Silicose/tratamento farmacológico , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Superóxido Dismutase/metabolismo , Resultado do Tratamento
7.
Chem Biodivers ; 6(7): 1053-65, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19623551

RESUMO

A phytochemical investigation of the roots of Ligularia atroviolacea resulted in the isolation of 24 compounds including seven new eremophilanoids named eremophila-3,7(11),8-triene-12,8;14,6alpha-diolide (1), 3beta-(angeloyloxy)eremophil-7(11)-en-12,8beta-olid-14-oic acid (2), 1alpha-chloro-10beta-hydroxy-6beta-(2-methylpropanoyloxy)-9-oxo-7,8-furoeremophilane (3), (10betaH)-8-oxoeremophila-3(4),6(7)-diene-12,14-dioic acid (4), (10alphaH)-8-oxoeremophila-3(4),6(7)-diene-12,14-dioic acid (5), 8beta-[eremophila-3',7'(11')-diene-12',8'alpha;14',6'alpha-diolide]eremophila-3,7(11)-diene-12,8alpha;14,6alpha-diolide (6), and ligulatrovine A (7), eleven known eremophilanoids, 8-18, four steroids, one glucose derivative, and one fatty acid. The structures of these compounds were elucidated by spectroscopic methods including 2D-NMR experiments. The structure of 3 was also established by an X-ray diffraction study. The in vitro cytotoxicity evaluation of selected compounds was performed on seven cultured tumor cell lines, i.e., KB, BEL-7404, A549, HL-60, HeLa, CNE, and P-388D1. The preliminary taxonomy of this species was also discussed, and the possible biogenesis of a dimer possessing a new noreremophilanoid type skeleton, 7, is presented in a preliminary form.


Assuntos
Antineoplásicos Fitogênicos/toxicidade , Asteraceae/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Compostos Orgânicos/química , Compostos Orgânicos/isolamento & purificação , Compostos Orgânicos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Raízes de Plantas/química , Plantas Medicinais/química
9.
J Org Chem ; 74(3): 1397-9, 2009 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-19117476

RESUMO

The TunePhos/diamine-Ru(II) complex combined with t-BuOK in 2-propanol effectively catalyzes enantioselective hydrogenation of a wide range of simple ketones including aromatic, heteroaromatic, alpha,beta-unsaturated, and cyclopropyl ketones, affording high reactivity (up to 1,000,000 TON) and excellent enantioselectivities (>99% ee for 13 examples).


Assuntos
Álcoois/síntese química , Diaminas/química , Cetonas/química , Compostos Organometálicos/química , Rutênio/química , Hidrogenação , Compostos Organometálicos/síntese química , Estereoisomerismo
10.
J Org Chem ; 73(3): 1143-6, 2008 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18171076

RESUMO

A convenient, divergent strategy for the synthesis of a series of modular and fine-tunable C3-TunePhos-type chiral diphosphine ligands and their applications in highly efficient Ru-catalyzed asymmetric hydrogenations were explored. Up to 97 and 99% ee values were achieved for the enantioselective synthesis of beta-methyl chiral amines and alpha-hydroxy acid derivatives, respectively.


Assuntos
Fosfinas/química , Rutênio/química , Água/química , Catálise , Ésteres/química , Hidrogenação , Ligantes , Estrutura Molecular , Estereoisomerismo
13.
J Cardiovasc Pharmacol ; 45(5): 447-55, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15821440

RESUMO

KATP channels are a complex of regulatory sulfonylurea receptor subunits and the pore-forming inward rectifiers such as Kir6.1. Using the whole-cell patch-clamp technique, we investigated the interaction of nicotine with the Kir6.1 subunit as well as the underlying mechanism. Stable expression of Kir6.1 in HEK-293 cells yielded a detectable inward rectifier KATP current. This inward current was significantly inhibited by PNU-37883A and by a specific anti-Kir6.1 antibody. Nicotine at 30 and 100 microM increased Kir6.1 currents by 42 +/- 11.8% and 26.2 +/- 14.6%, respectively (n = 4-6, P < 0.05). In contrast, nicotine at 1-3 mM inhibited Kir6.1 currents (P < 0.05). Nicotine at 100 microM increased the production of superoxide anion (O2) by 20.3 +/- 5.7%, whereas at 1 mM it significantly decreased the production of O2 by 37.7 +/- 4.3%. Coapplication of hypoxanthine (HX) and xanthine oxidase (XO) to the transfected HEK-293 cells resulted in a significant and reproducible increase in Kir6.1 currents (P < 0.05). The stimulatory effect of HX/XO on Kir6.1 current was abolished by tempol, a scavenger of O2. Tempol also abolished the stimulatory effect of 30 muM nicotine on Kir6.1 currents. In conclusion, nicotine stimulates Kir6.1 channel at least in part through the production of O2.


Assuntos
Transportadores de Cassetes de Ligação de ATP/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/fisiologia , Nicotina/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização/efeitos dos fármacos , Canais de Potássio Corretores do Fluxo de Internalização/fisiologia , Canais de Potássio/fisiologia , Superóxidos/metabolismo , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/genética , Linhagem Celular , Óxidos N-Cíclicos/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Hipoxantina/farmacologia , Canais KATP , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/efeitos dos fármacos , Canais de Potássio Corretores do Fluxo de Internalização/antagonistas & inibidores , Canais de Potássio Corretores do Fluxo de Internalização/genética , Espécies Reativas de Oxigênio/antagonistas & inibidores , Marcadores de Spin , Superóxidos/análise , Transfecção , Xantina/farmacologia
14.
J Neurophysiol ; 93(3): 1699-709, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15738276

RESUMO

Voltage-gated potassium channels are well established as critical for setting action potential frequency, membrane potential, and neurotransmitter release in neurons. However, their role in the "nonexcitable" glial cell type is yet to be fully understood. We used whole cell current kinetics, pharmacology, immunocytochemistry, and RT-PCR to characterize A-type current in hippocampal astrocyte cultures to better understand its function. Pharmacological analysis suggests that approximately 70, 10, and <5% of total A current is associated with Kv4, Kv3, and Kv1 channels, respectively. In addition, pharmacology and kinetics provide evidence for a significant contribution of KChIP accessory proteins to astrocytic A-channel composition. Localization of the Shaw Kv3.4 channel to astrocytic processes and the Shal Kv4.3 channel to soma suggest that these channels serve a specific function. Given this complex A-type channel expression pattern, we assessed the role of A currents in membrane voltage oscillations in response to current injections. Although TEA-sensitive delayed-rectifying currents are involved in the extent of repolarization, 4-AP-sensitive A currents serve to increase the rate. As in neurons, this effect may enable astrocytes to respond rapidly to high-frequency synaptic events. Our results indicate that hippocampal astrocytes in vitro express multiple A-type Kv channel alpha-subunits with accessory, possibly Ca(2+)-sensitive, cytoplasmic subunits that appear to be specifically localized to subcellular membrane compartments. Function of these channels remains to be determined in a physiological setting. However, this study suggests that they enable astrocytes to respond rapidly with membrane voltage oscillations to high-frequency incoming signals, possibly synchronizing astrocyte function to neuronal activity.


Assuntos
Astrócitos/metabolismo , Hipocampo/citologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , 4-Aminopiridina/farmacologia , Ácido 5,8,11,14-Eicosatetrainoico/farmacologia , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Northern Blotting/métodos , Cálcio/metabolismo , Células Cultivadas , Estimulação Elétrica/métodos , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/metabolismo , Humanos , Imuno-Histoquímica/métodos , Ativação do Canal Iônico/efeitos dos fármacos , Ativação do Canal Iônico/fisiologia , Ativação do Canal Iônico/efeitos da radiação , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Técnicas de Patch-Clamp/métodos , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/classificação , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Tetraetilamônio/farmacologia , Transfecção/métodos
15.
FASEB J ; 18(14): 1782-4, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15371330

RESUMO

The endogenous production of hydrogen sulfide (H2S) and its physiological functions, including membrane hyperpolarization and smooth muscle cell relaxation, position this gas well in the family of gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). In this study, we demonstrate that H2S at physiologically relevant concentrations induced apoptosis of human aorta smooth muscle cells (HASMCs). Exposure of HASMCs to H2S did not induce necrosis as verified with Trypan blue exclusion and LDH release analysis. After inhibiting endogenous H2S production, exogenous H2S induced much more significant apoptosis, which was not altered by the presence of albumin or glutathione. H2S treatment increased the activities of ERK and p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase activity. Suppression of extracellular signal-regulated kinase (ERK) activity, but not of p38 activity, inhibited the H2S-induced apoptosis of HASMCs. The activation of ERK by H2S in HASMCs was accompanied by increased caspase-3 activity. Inhibition of caspase-3 by AC-DEVD-CHO attenuated the H2S-induced cell apoptosis. Inhibition of ERK by U0126 decreased caspase-3 activity, whereas AC-DEVD-CHO did not alter ERK activity. In conclusion, exogenous H2S induces apoptosis of HASMCs, which is significantly affected by the endogenous H2S level. Of the three investigated MAPKs, only ERK played an active role in mediating H2S-induced apoptosis of HASMCs by activating caspase-3. These findings may help reveal novel mechanisms for many diseases linked to H2S-related abnormal cellular proliferation and apoptosis.


Assuntos
Apoptose , Caspases/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Sulfeto de Hidrogênio/farmacologia , Sistema de Sinalização das MAP Quinases , Músculo Liso Vascular/enzimologia , Aorta/citologia , Caspase 3 , Inibidores de Caspase , Células Cultivadas , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Humanos , Sulfeto de Hidrogênio/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Músculo Liso Vascular/citologia
16.
Biochem Pharmacol ; 67(1): 147-56, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14667937

RESUMO

K(ATP) channels are composed of pore-forming subunits Kir6.x and auxiliary subunits SURx. These channels play important roles in modulating the contractility of vascular smooth muscle cells (SMCs) by altering membrane potentials. The molecular basis of K(ATP) channels in vascular SMCs is unclear and the expression of different K(ATP) channel subunits at protein level in various tissues still undetermined. In this study, using an anti-Kir6.1 antibody, we detected the expression of Kir6.1 proteins in rat vascular tissues including mesenteric artery, pulmonary artery, aorta, and tail artery. Kir6.1 proteins were also identified in heart and other non-vascular tissues including spleen and brain, but they were undetectable in liver and kidney. Immunocytochemical study revealed the expression of Kir6.1 proteins in cultured rat thoracic aortic SMCs. Using the whole-cell patch-clamp technique, it was found that the intracellularly applied anti-Kir6.1 antibody significantly inhibited K(ATP) channel currents in HEK-293 cells that were stably transfected with Kir6.1 cDNA. A better understanding of differential expression of Kir6.1 proteins in various vascular and non-vascular tissues may help discern different molecular basis and functions of K(ATP) channel complexes in these tissues.


Assuntos
Expressão Gênica , Músculo Liso Vascular/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Animais , Anticorpos/análise , Células COS , Células Cultivadas , Eletrofisiologia , Humanos , Canais de Potássio Corretores do Fluxo de Internalização/biossíntese , Canais de Potássio Corretores do Fluxo de Internalização/imunologia , Distribuição Tecidual
17.
Phytochemistry ; 63(7): 835-9, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12877925

RESUMO

Four eudesmane glucosides, alatosides A-D (1-4), and one megastigmane glucoside, alatoside E (5), were isolated from the BuOH fraction of Laggera alata along with six known compounds. Structures of the new compounds were elucidated by a combination of chemical and spectroscopic methods. Alatosides A-E were characterized as: 1alpha-O-(beta-D-glucopyranosyloxyl)-7-epi-eudesma-11-en-2beta,4alpha-diol (1), 2beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4alpha-hydroxyl-11(13)-en-12-oic-acid (2), 5beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4(15),11(13)-dien-12-oic-acid (3), 5alpha-O-(beta-D-glucopyranosyloxyl)-eudesma-3,11(13)-dien-12-oic acid (4) and 3beta-O-(beta-D-glucopyranosyloxyl)-megastigma-9-one (5), respectively. Based on the chemical characteristics of eudesmane derivatives isolated from the Laggera genus, it was suggested that there are probably two different biogenetic pathways for these secondary metabolites in this genus.


Assuntos
Asteraceae/química , Cicloexanonas/química , Glucosídeos/química , Glucosídeos/isolamento & purificação , Norisoprenoides/química , Sesquiterpenos de Eudesmano/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular
18.
Mol Cell Biochem ; 238(1-2): 69-79, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12349911

RESUMO

The human embryonic kidney cells (HEK-293) have been widely used as one mammalian expression system in the study of voltage-gated K+ (Kv) channels. Understanding the endogenous Kv channels in these cells is the prerequisite for the characterization of the heterogeneously expressed Kv channels in these cells. In the present study we screened the transcriptional expression of different Kv genes in HEK-293 cells using reverse transcribed DNApolymerase chain reaction (RT-PCR) method. Among 16 Kv genes examined in native HEK-293 cells 10 Kv genes were reproducibly amplified, including those Kv a subunits encoding for the delayed rectifier (IK) [Kv1.1, Kv1.2, Kv1.3, Kv1.6, and Kv3.1], and for the transient outward Kv channels (IA) [Kv1.4, Kv3.3, Kv3.4, and Kv4.1] as well as a Kvbeta2 subunit. The whole-cell outward rectifier IK currents in the native HEK-293 cells were recorded (203 +/- 13 pA at +30 mV, n = 82) with the patch-clamp technique. In about 42% of the examined cells, IA coexisted with IK currents. IK currents were inhibited by tetraethylammonium chloride (TEA) at 1 and 10 mM by 39.5 and 48.4%, respectively. A 39.6% inhibition of IK currents was also observed in the presence of4-aminopyridine (4-AP, 5 mM). Interestingly, both TEAand 4-AP also inhibited IA currents. 4-acelamido-4'-isothiocyanalostilbene-2, 2'-disulfonic acid (1 mM), a Cl- channel blocker, had no effect on the endogenous outward currents. We concluded that multiple endogenous Kv genes were expressed in native HEK-293 cells, which possessed significant endogenous IK and IA currents with unique pharmacological properties.


Assuntos
Rim/embriologia , Rim/metabolismo , Canais de Potássio/metabolismo , Linhagem Celular , Interpretação Estatística de Dados , Condutividade Elétrica , Eletrofisiologia , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Rim/citologia , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/química , Canais de Potássio/genética , Subunidades Proteicas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canais de Potássio Shal , Tetraetilamônio/farmacologia
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