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1.
Int J Nanomedicine ; 14: 7975-7985, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632012

RESUMO

BACKGROUND: Multidrug-resistant bacteria such as extended-spectrum beta-lactamase (ESBL), Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus (MRSA) pose a challenge to the human health care system. MRSA is among the major causes of hospital-acquired and community infections. METHODS: Therefore, in the present study, we evaluated the antibacterial activity of silver nanoparticles synthesized by Fusarium oxysporum (AgNPbio) in combination with simvastatin against reference and multidrug-resistant bacterial strains. RESULTS: Simvastatin showed a minimal inhibitory concentration (MIC) ranging from 0.062 to 0.25 mg mL-1 against MRSA. AgNPbio with a size of 77.68± 33.95 nm and zeta potential -34.6 ± 12.7 mV showed an MIC of 0.212 mg mL-1 against S. aureus including MRSA strains. The checkerboard assay and time-kill curves exhibited a synergistic effect of the simvastatin-AgNPbio combination on antibacterial activity against MRSA strains. The combination of simvastatin and AgNPbio demonstrated antibacterial activity against Escherichia coli producing ESBL. Scanning electron microscopy showed the formation of cell surface protrusions after treatment with AgNPbio and the formation of a large amorphous mass after treatment with simvastatin, both in MRSA. CONCLUSION: Our results indicate that the combination of AgNPbio and simvastatin could be a great future alternative in the control of bacterial infections, where, when combined with simvastatin, smaller doses of AgNPbio are required, with the same antibacterial activity.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fusarium/metabolismo , Nanopartículas Metálicas/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Prata/farmacologia , Sinvastatina/farmacologia , Morte Celular/efeitos dos fármacos , Sinergismo Farmacológico , Eritrócitos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Fusarium/ultraestrutura , Humanos , Nanopartículas Metálicas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana
2.
Sci Rep ; 6: 21641, 2016 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-26869239

RESUMO

Several studies have tested antimicrobial activity of combinations of honey and various substances. In this study, we tested a combination of two stingless bee honeys against various bacterial strains. In particular: the antibacterial activity of honeys produced by Scaptotrigona bipunctata (SB) and Scaptotrigona postica (SP) was evaluated against Gram-positive and Gram-negative bacterial strains by agar well diffusion assays, minimum inhibitory concentration (MIC) assessment, construction of growth and viability curves and scanning electron microscopy (SEM). The interaction of the two honeys was also evaluated by the checkerboard assay. Inhibition zones ranged from 8 to 22 mm. The MIC values of the individual honeys ranged from 0.62 to 10% (v v(-1)) and decreased to 1/4 to 1/32 when the honeys were combined. SEM images showed division inhibition and cell wall disruption for the SB and SP honeys, respectively, and these alterations were observed in same field when the SB and SP honeys were combined. This study demonstrated that the natural honeys possess in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. Combination of the SB and SP honeys could lead to the development of new broad-spectrum antimicrobials that have the potential to prevent the emergence of resistant bacterial strains.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Mel , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Animais , Abelhas , Bactérias Gram-Positivas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana
3.
In. Sala, Arnaldo; Seixas, Paulo Henrique D'Ângelo. I Mostra SES/SP 2007: experiências inovadoras na gestão da saúde no Estado de São Paulo. São Paulo, SES/SP, 2008. p.91-95, tab, graf.
Monografia em Português | LILACS, Sec. Est. Saúde SP, SESSP-CTDPROD, Sec. Est. Saúde SP | ID: lil-503595

RESUMO

A avaliação de desempenho passou a ser empregada nas empresas com o objetivo de alcançar um desenvolvimento maior do homem, das relações humanas e do trabalho desenvolvido. É uma técnica utilizada para obter informações sobre o comportamento profissional do funcionário. Clientes e usuários estão cada vez mais exigentes com os produtos e serviços de que dispõem, e a questão da qualidade tem apresentado crescente preocupação em todo o mundo. A nova consciência de qualidade dos produtos e serviços concede mais valorização aos esforços do indivíduo, considerando-se que as pessoas envolvidaS são fundamentais, pois a qualidade depende do trabalho individual ou em grupo. A preocupação dos hospitais, atualmente, pela busca da qualidade dos serviços vem exigindo de seus profissionais e colaboradores uma nova postura...


Assuntos
Análise Institucional , Avaliação de Desempenho Profissional , Planejamento Estratégico
4.
Int J Gynecol Cancer ; 13(1): 47-52, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12631220

RESUMO

The objective of this research is whether the classification of vascular invasion severity can be used as a prognostic factor in cases of uterine endometrial cancer. Sixty-five patients with stage I to III uterine endometrial cancer were included in the study. All patients were seen between 1987 and 1997, and the types of their cancers were histologically confirmed. The degree of vascular invasion was classified according to three different systems: (1). positive or negative; (2). negative, mild, or severe; and (3). negative, mild, moderate, or severe. For each classification, the disease-free survival rate was calculated according to various pathologic factors using the Wilcoxon test; multivariate analyses were performed using the Cox proportional hazard model. Patients with severe vascular invasion showed a significantly lower disease-free survival rate than did patients with moderate or less severe invasion. In the multivariate analysis, severe vascular invasion was shown to be an independent prognostic factor indicating a high relative risk. We conclude that the severity of vascular invasion is an important histopathologic factor in determining the prognosis of uterine endometrial cancer. Vascular invasion classification systems employing three subjective or four objective categories may be more appropriate than a positive/negative classification system for judging the prognosis in cases of uterine endometrial cancer.


Assuntos
Neoplasias do Endométrio/patologia , Estadiamento de Neoplasias , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Endométrio/mortalidade , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Modelos de Riscos Proporcionais , Análise de Sobrevida
5.
Life Sci ; 68(17): 1989-2000, 2001 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-11388701

RESUMO

Thrombin is a potent mitogen for vascular smooth muscle cells. However, the signaling pathways by which thrombin mediates its mitogenic response are not fully understood. The ERK (extracellular signal-regulated protein kinase) and JNK (c-Jun N-terminal kinase) members of the mitogen-activated protein kinase (MAPK) family are reported to be activated by thrombin. We have investigated the response to thrombin of another member of the MAPK family, p38 MAPK, which has been suggested to be activated by both stress and inflammatory stimuli in vascular smooth muscle cells. We found that thrombin induced time- and dose-dependent activation of p38 MAPK. Maximal stimulation of p38 MAPK was observed after a 10-min incubation with 1 unit ml(-1) thrombin. GF109203X, a protein kinase C inhibitor, and prolonged treatment with phorbol 12-myristate 13-acetate partially inhibited p38 MAPK activation. A tyrosine kinase inhibitor, genistein, also inhibited p38 MAPK activation in a dose-dependent manner. p38 MAPK activation was inhibited by overexpression of betaARK1ct (beta-adrenergic receptor kinase I C-terminal peptide). p38 MAPK activation was also inhibited by expression of dominant-negative Ras, not by dominant-negative Rac. We next examined the effect of a p38 MAPK inhibitor, SB203580, on thrombin-induced proliferation. SB203580 inhibited thrombin-induced DNA synthesis in a dose-dependent manner. These results suggest that thrombin activates p38 MAPK in a manner dependent on Gbetagamma, protein kinase C, a tyrosine kinase, and Ras, that p38 MAPK has a role in thrombin-induced mitogenic response in the cells.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/enzimologia , Trombina/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/enzimologia , Aorta Torácica/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Cultivadas , DNA/biossíntese , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Proteínas Heterotriméricas de Ligação ao GTP/fisiologia , Imidazóis/farmacologia , Indóis/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Maleimidas/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/fisiologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/fisiologia , Piridinas/farmacologia , Ratos , Acetato de Tetradecanoilforbol/farmacologia , Trombina/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno
6.
Life Sci ; 67(16): 1983-92, 2000 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-11072874

RESUMO

We previously reported that oxidized low density lipoprotein (ox-LDL) induced apoptosis in vascular smooth muscle cells (VSMCs). However, the transcription factors important for apoptotic signalling have been little clarified. We investigated the involvement of nuclear factor-kappaB (NF-kappaB), by which apoptotic signalling is reported to be mediated, in ox-LDL-induced apoptosis. The effect of ox-LDL on the transcriptional factor NF-kappaB activation was investigated by electrophoretic mobility shift assay (EMSA). Ox-LDL caused NF-kappaB activation in VSMCs. Next, we investigated the effect on ox-LDL-induced apoptosis by introduction of synthetic double-stranded DNA with high affinity for NF-kappaB in vitro as "decoy" cis elements that bind the transcriptional factor. Treatment by transfection of NF-kappaB decoy oligodeoxynucleotides (ODN), but not scramble ones, blunted the activation of NF-kappaB by ox-LDL and caused a significant further induction of ox-LDL-induced apoptosis. Results indicate that the activation of NF-kappaB prevents excessive apoptosis by ox-LDL in VSMCs.


Assuntos
Apoptose/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , NF-kappa B/antagonistas & inibidores , Animais , Aorta Torácica/citologia , Aorta Torácica/efeitos dos fármacos , Apoptose/fisiologia , Células Cultivadas , DNA/metabolismo , Sinergismo Farmacológico , Humanos , Mimetismo Molecular , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , NF-kappa B/metabolismo , Oligodesoxirribonucleotídeos/genética , Oligodesoxirribonucleotídeos/metabolismo , Oligodesoxirribonucleotídeos/farmacologia , Fosfatos/metabolismo , Fosfatos/farmacologia , Coelhos , Ratos , Especificidade por Substrato , Transfecção
7.
J Reprod Med ; 45(5): 387-9, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10845171

RESUMO

OBJECTIVE: To evaluate the efficacy of an oxidized regenerated cellulose adhesion barrier as an adjuvant in preventing postoperative adhesions in infertile women undergoing reconstructive surgery. STUDY DESIGN: Thirty-eight cases of reconstructive surgery that could be followed up for more than two years (myomectomy 19, cystectomy 5, tuboplasty 10, uteroplasty 4) at the Fujita Health University Hospital were evaluated retrospectively. The barrier (Intercede, Johnson & Johnson) was used to cover the surgical site in 23 of these cases (Intercede group); no adjuvant was used in 15 cases, which represent the surgical control group (Intercede - group), including 23 second-look operation cases (16 in the Intercede and 7 in the control group). Postoperative adhesion prevention and pregnancy rates were estimated. RESULTS: At the second-look operation, six cases (37.5%) in the Intercede + group and six (85.7%) in the Intercede - group had postoperative adhesions. No significant difference was found in either intensity or area covered with adhesions between the two groups. Eighteen cases (78.3%) in the Intercede and seven (46.7%) in the Intercede - group conceived during the follow-up period. CONCLUSION: The use of Intercede significantly reduced the rate of postoperative adhesion formation, with a statistically significant increase in the pregnancy rate as compared to the surgical controls.


Assuntos
Celulose Oxidada/uso terapêutico , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Infertilidade Feminina/cirurgia , Doenças Peritoneais/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Feminino , Humanos , Doenças Peritoneais/etiologia , Gravidez , Taxa de Gravidez , Reoperação , Estudos Retrospectivos , Aderências Teciduais/etiologia , Aderências Teciduais/prevenção & controle , Resultado do Tratamento
8.
Jpn J Pharmacol ; 80(4): 375-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10496339

RESUMO

As we reported previously, both wortmannin and lovastatin inhibit the differentiation in 3T3-L1 cells when these drugs were applied during the insulin-induced cell differentiation. In the present study, 3T3-L1 cells were treated with wortmannin and simvastatin after the completion of the insulin-stimulation, and differentiation was found to be significantly decreased by these drugs. This suggests intracellular signaling pathways play roles in the differentiation of 3T3-L1 cells even after the completion of the insulin-stimulation and also suggests that not only the early phase (day 0 to day 2) but also the late phase (day 2 to day 4) of differentiation is important for the differentiation of the cells.


Assuntos
Adipócitos/metabolismo , Androstadienos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sinvastatina/farmacologia , Células 3T3 , Adipócitos/efeitos dos fármacos , Animais , Células Cultivadas , Hipolipemiantes/farmacologia , Insulina/farmacologia , Antagonistas da Insulina/farmacologia , Camundongos , Fatores de Tempo , Wortmanina
9.
Eur J Pharmacol ; 374(1): 127-35, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10422649

RESUMO

While vascular smooth muscle cell proliferation is important in hypertension, relatively little is known about the contribution of catecholamines. Novel insulin sensitizing agents, thiazolidinediones, have been demonstrated to inhibit angiotensin II-, basic fibroblast growth factor (FGF)-induced growth of vascular smooth muscle cells. We hypothesize that these agents might also inhibit the effect of the stimulation of alpha1-adrenoreceptors on the proliferation of vascular smooth muscle cells. Troglitazone (1-20 microM), a member of the thiazolidinediones, significantly inhibited the stimulation of alpha1-adrenoreceptor-induced DNA synthesis, c-fos induction and mitogen-activated protein (MAP)-kinase activation. This effect was associated with inhibition by troglitazone of the transactivation of the serum response element (SRE), which regulates c-fos expression. Inhibition of c-fos induction by troglitazone appeared to occur via blockade of the upstream of MAP kinase activation in vascular smooth muscle cells. At this dose, troglitazone inhibited the ternary complex factor (TCF)-dependent activation, which is regulated by MAP kinase activation, but did not inhibit the TCF-independent SRE activation. Besides, the degree of the inhibitory effect of troglitazone on MAP kinase activation, DNA synthesis, c-fos expression differs. This may show that troglitazone work on multiple sites. These results suggest that troglitazone is a potent inhibitor of vascular smooth muscle cells proliferation through the downregulation of c-fos expression and may be a useful agent for prevention of atherosclerosis which is a result of hypertension.


Assuntos
Cromanos/farmacologia , DNA/biossíntese , Hipoglicemiantes/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Tiazóis/farmacologia , Tiazolidinedionas , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Proteínas de Ligação a DNA/efeitos dos fármacos , Genes fos , Músculo Liso Vascular/metabolismo , Proteínas Nucleares/efeitos dos fármacos , Oligonucleotídeos Antissenso/farmacologia , Fenilefrina/farmacologia , Ratos , Receptores Adrenérgicos alfa 1/fisiologia , Elementos de Resposta/efeitos dos fármacos , Fator de Resposta Sérica , Ativação Transcricional/efeitos dos fármacos , Troglitazona , Fosfolipases Tipo C/metabolismo
10.
Eur J Pharmacol ; 371(1): 69-74, 1999 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-10355596

RESUMO

Na+/H+ exchange has been proposed to be involved in the regulation of cell growth. However, little is known about the regulatory pathway and relationship between Na+/H+ exchange and DNA synthesis. In vascular smooth muscle cells, platelet-derived growth factor (a tyrosine kinase-coupled receptor agonist) and thrombin (a G protein-coupled receptor agonist) stimulate both activation of Na+/H+ exchange and DNA synthesis. In this study, we compared the effect of platelet-derived growth factor (PDGF) and thrombin on the signal transduction pathway leading to the activation of these responses in A10 cells, clonal rat thoracic aortic smooth muscle cells. To investigate the role of mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase as potential mediators, we examined the effect of pharmacological kinase inhibitors on these responses. The Na+/H+ exchange activity induced by thrombin was inhibited by a specific inhibitor of MAPK kinase, 2'-amino-3'-methoxyflavone (PD98059), but was not affected by a specific phosphatidylinositol-3-kinase inhibitor, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002). Thrombin-induced DNA synthesis was inhibited by LY294002, but not by PD98059. In contrast, the Na+/H+ exchange activity induced by PDGF was inhibited by neither LY294002 nor PD98059, but PDGF-induced DNA synthesis was inhibited by both LY294002 and PD98059. These data suggest that, in A10 cells, Na+/H+ exchange activation and DNA synthesis are differently regulated by the two extracellular stimuli.


Assuntos
DNA/biossíntese , Músculo Liso Vascular/fisiologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Trocadores de Sódio-Hidrogênio/fisiologia , Trombina/farmacologia , Animais , Aorta Torácica/fisiologia , Linhagem Celular , Interações Medicamentosas , Concentração de Íons de Hidrogênio , Inibidores de Proteínas Quinases , Ratos , Timidina/metabolismo
11.
Life Sci ; 63(17): 1563-70, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9808067

RESUMO

A tyrosine kinase receptor-mediated and a heterotrimeric G protein-coupled receptor-mediated signals have been shown to evoke distinct intracellular signaling events. There has been increasing evidence that cross-talk exists between a tyrosine kinase receptor-mediated and a heterotrimeric G protein-coupled receptor-mediated signal transduction pathways. In the present study, we have studied effects of EGF receptor activation on activities of inhibitory G protein (Gi). We show that the amounts of Gi/Go ADP-ribosylated by islet-activating protein (IAP) increased by 30-40% in the membranes of Rat 1 fibroblast cells pretreated with EGF compared with those without pretreatment. When an effect of lysophosphatidic acid (LPA) stimulation on an adenylate cyclase activity was examined, LPA partly attenuated forskolin-stimulated adenylate cyclase activity via Gi because IAP pretreatment blocked the inhibitory effect of LPA. Pretreatment with EGF reduced the ability of LPA to inhibit the forskolin-stimulated adenylate cyclase activity, while the pretreatment did not have any effects on the forskolin-stimulated activity. Thus, the EGF receptor-mediated signal appears to cause the impairment of Gi function in Rat 1 fibroblast cells.


Assuntos
Adenilil Ciclases/metabolismo , Receptores ErbB/metabolismo , Fibroblastos/efeitos dos fármacos , Lisofosfolipídeos/farmacologia , Receptor Cross-Talk/fisiologia , Transdução de Sinais , Toxina Adenilato Ciclase , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , Colforsina/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Fibroblastos/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Toxina Pertussis , Ratos , Fatores de Virulência de Bordetella/farmacologia
12.
Life Sci ; 63(6): 429-39, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9718067

RESUMO

Aspirin and sodium salicylate enhance to a similar extent the production of nitric oxide (NO) in cultured smooth muscle cells following stimulation by interleukin-1beta (IL-1beta). The similar potencies of aspirin and sodium salicylate indicate that acetylation of cellular macromolecules is not essential for the enhancement of NO production. The failure of added prostaglandin E2 (PGE2) or Thromboxane A2 (TXA2) to overcome the effects of aspirin or sodium salicylate indicates that these effects are not simply the result of inhibition of prostaglandin synthesis. The enhancement of NO production occurs dependent of the effects of these agents on induction of inducible nitric oxide synthase (iNOS) expression by IL-1beta. Aspirin and sodium salicylate enhance the induction of iNOS expression by IL-1beta. We previously reported that pretreatment of vascular smooth muscle cells (VSMCs) with high glucose decreased the response of the cells by IL-1beta, that is, the induction of iNOS expression and NO production. We investigated the effect of aspirin and sodium salicylate on the response by IL-1beta of VSMCs pretreated with high glucose (25 mM). Aspirin and sodium salicylate ameliorate the down-regulation of iNOS expression and the decrease of NO production caused by pretreatment with high glucose (25 mM). These results suggest a possible therapeutic role in atherosclerotic disease and diabetes mellitus for aspirin and sodium salicylate by enhancing the level of iNOS expression and NO production.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Músculo Liso Vascular/enzimologia , Óxido Nítrico Sintase/biossíntese , Salicilato de Sódio/farmacologia , Animais , Western Blotting , Células Cultivadas , Regulação para Baixo , Indução Enzimática , Glucose/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II , Nitritos/metabolismo , Ratos
13.
Eur J Pharmacol ; 347(1): 125-30, 1998 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-9650858

RESUMO

We investigated whether contraction-induced agonists such as alpha1-adrenoceptor agonists are important regulators of smooth muscle cell hypertrophy by examining the effects of one potent agonists, phenylephrine, on the hypertrophy. Under the experimental conditions used, we found that phenylephrine was potent in inducing alpha1-adrenoreceptor-dependent hypertrophy of vascular smooth muscle cells as defined by increased incorporation of [14C]leucine in a dose-dependent fashion. Further, we assessed the effect of lovastatin, an 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on hypertrophy of cultured vascular smooth muscle cells as defined by the increased incorporation of [14C]leucine caused by phenylephrine. Lovastatin (5-15 microM) caused a significant dose-dependent reduction in [14C]leucine incorporation which was completely prevented in the presence of exogenous mevalonate (100 microM). Exogenous low density lipoprotein (100 microg/ml) and cholesterol (15 microg/ml) did not prevent lovastatin inhibition of [14C]leucine incorporation. In contrast, the isoprenoid farnesol largely prevented inhibition of [14C]leucine incorporation by the lovastatin. We conclude that mevalonate metabolites are essential for phenylephrine-induced smooth muscle cell hypertrophy, possibly through the production of the isoprenoid farnesol.


Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Farneseno Álcool/metabolismo , Ácido Mevalônico/metabolismo , Músculo Liso Vascular/patologia , Receptores Adrenérgicos alfa 1/fisiologia , Animais , Anticolesterolemiantes/antagonistas & inibidores , Anticolesterolemiantes/farmacologia , Aorta Torácica/patologia , Aorta Torácica/ultraestrutura , Radioisótopos de Carbono , Contagem de Células , Células Cultivadas , Colesterol/metabolismo , Interações Medicamentosas , Farneseno Álcool/farmacologia , Hipertrofia , Leucina/metabolismo , Lovastatina/antagonistas & inibidores , Lovastatina/farmacologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/ultraestrutura , Fenilefrina/farmacologia , Prenilação de Proteína , Ratos , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Transferases/antagonistas & inibidores , Transferases/metabolismo
14.
Life Sci ; 62(15): 1339-47, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9566776

RESUMO

Cigarette smoking is associated with an increased incidence of atherosclerotic disease. In this study, we examined the mechanism underlying the growth-modulating effects of cigarette smoke extract (CSE) in confluent vascular smooth muscle cells (VSMCs). The treatment of VSMC by CSE decreased the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase of VSMC in a time-dependent manner. In mitogenesis assays using the confluent cells, CSE was not a direct mitogen for VSMC, but potentiated the stimulatory effect of hydrogen peroxides. The reduction of activities of catalase and glutathione peroxidase was partially prevented by SH-containing compounds. In summary, CSE enhanced the mitogenic effect response of hydrogen peroxides, largely depending on the dysregulation of the activities of SOD, catalase and glutathione peroxidase by CSE.


Assuntos
Músculo Liso Vascular/citologia , Fumar/efeitos adversos , Animais , Catalase/metabolismo , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/enzimologia , Ratos , Compostos de Sulfidrila/farmacologia , Superóxido Dismutase/metabolismo
15.
Life Sci ; 62(3): 239-45, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9488102

RESUMO

Previously we have shown that nitric oxide (NO) donors induced apoptosis in vascular smooth muscle cells (VSMCs). However, the mechanisms by which NO induced apoptosis in VSMCs are entirely unknown. In the present study, we intended to identify the mechanism by which NO donors induce apoptosis in VSMCs. First, we evaluated the expression of c-Myc, P53, and Bcl-2 proteins in VSMCs treated by NO donors. c-Myc and P53 protein expression increased after VSMCs were incubated with NO donors for 6 hr and reached a maximum level at 24 hr, while Bcl-2 protein decreased after 12 hr incubation. Next we investigated to see whether the CPP32 protease activation was involved in NO donors-induced apoptosis. In VSMCs treated by NO donors, the increase of CPP32 protease activity was observed and specific inhibition of CPP32 activity significantly prevented apoptosis induced by NO donors in a dose-dependent manner. These results suggest that NO donors induced apoptosis through proto-oncoprotein expression and CPP32-like protease activation.


Assuntos
Apoptose , Caspases , Cisteína Endopeptidases/metabolismo , Proteínas Oncogênicas/metabolismo , Animais , Caspase 3 , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Ativação Enzimática , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Coelhos
16.
Br J Pharmacol ; 122(2): 269-74, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9313935

RESUMO

1. Homocysteine is an independent risk factor for cardiovascular disease. The mechanisms by which elevated plasma concentrations of homocysteine are related to the pathogenesis of atherosclerosis are not fully understood. Therefore, we examined the effect of homocysteine on cell replication of rat cultured vascular smooth muscle cells (VSMCs) at concentrations similar to those observed in clinical studies. 2. The incorporation of [3H]-thymidine was used as a marker of mitosis. Homocysteine (250-500 microM) was a weak mitogen as compared to platelet-derived growth factor-BB (PDGF-BB, 1 nM) and serum (10%), but it potentiated the mitogenic effect of PDGF-BB four fold at 500 microM. This enhancement of mitogenesis was blunted by the addition of the scavenging enzyme catalase or the antioxidant N-acetyl-L-cysteine. 3. Furthermore, stimulation of VSMC with homocysteine (25-500 microM) decreased the glutathione peroxidase activity of the cells to 50% of control at 500 microM. Inversely, homocysteine enhanced the superoxide dismutase (SOD) activity to 137% of control at 500 microM, but it had no effect on the catalase activity. 4. Homocysteine decreased the activity of bovine purified liver cytosolic glutathione peroxidase in a time- and dose-dependent manner. The maximum decrease was 50%. 5. In summary, homocysteine has a weak mitogenic effect on VSMC, but it dramatically enhances the mitogenic response of PDGF-BB, presumably by disturbing the activity of antioxidant enzymes.


Assuntos
Homocisteína/farmacologia , Peróxido de Hidrogênio/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/farmacologia , Animais , Antioxidantes/farmacologia , Becaplermina , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Glutationa Peroxidase/metabolismo , Músculo Liso Vascular/metabolismo , Proteínas Proto-Oncogênicas c-sis , Ratos , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
17.
Biochem Biophys Res Commun ; 236(2): 289-93, 1997 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-9240427

RESUMO

Cigarette smoking is associated with an increased incidence of premature atherosclerosis. Minimal information is available at the molecular level concerning the mechanism of action of cigarette smoke. Recent work has shown that paraoxonase (PON) protects low density lipoprotein against oxidation by Cu2+. The goal of the present study was to investigate the effect of cigarette smoke extract (CSE) on human plasma paraoxonase activity. The activity of paraoxonase was inhibited by the CSE in a dose- and time-dependent manner. The inhibition of PON activity by the CSE was reversed by the addition of glutathione or N-acetyl cysteine. Furthermore, we tested to see whether sulfhydryl compounds prevented the inhibition of PON activity caused by CSE. Sulfhydryl compounds prevented the inhibition of PON activity caused by CSE. But any amino compounds, such as N-acetyl lysine, N-acetyl arginine and aminoguanidine, failed to protect PON activity, indicating a specificity with regard to the ability of free thiols to buffer the deleterious components of CSE which inhibited PON activity. The observed inhibition of PON activity by CSE may account for the increased incidence of cardiovascular disease known to be present in smokers through the oxidative process of low density lipoprotein and its subsequent uptake by macrophage.


Assuntos
Esterases/sangue , Lipoproteínas LDL/metabolismo , Nicotiana , Plantas Tóxicas , Arildialquilfosfatase , Ácido Ditionitrobenzoico/química , Esterases/antagonistas & inibidores , Esterases/química , Humanos , Oxirredução , Fumaça , Compostos de Sulfidrila/metabolismo , Reagentes de Sulfidrila
18.
Br J Pharmacol ; 121(4): 665-70, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9208132

RESUMO

1. In a previous study, we demonstrated phenylephrine-stimulated arachidonic acid (AA) release in rabbit cultured aortic smooth muscle cells. Therefore, we have investigated the functional implications of AA which are involved in the cellular response to phenylephrine, particularly proliferation and migration of rabbit cultured aortic smooth muscle cells. 2. First, to determine whether AA directly modifies proliferation and mobility of vascular smooth muscle cells (VSMCs), we exposed the cells to AA. AA induced proliferation and migration of the cells in a dose-dependent fashion. Concomitantly added catalase inhibited the proliferation and chemotaxis induced by AA of VSMCs. Conversely, aminotriazole enhanced the proliferation and migration induced by AA. 3. Secondly, we investigated whether the proliferation and migration of VSMCs by phenylephrine were related to AA and hydrogen peroxide (H2O2). The proliferation and chemotaxis of VSMCs by phenylephrine were inhibited by a phospholipase A2 (PLA2) inhibitor, or catalase. 4. Lastly, we investigated the effects of AA and phenylephrine on the content of H2O2 in VSMCs. AA and phenylephrine treatment led to an increase of H2O2 in a dose-dependent manner. 5. These results suggest that the addition of phenylephrine to the cells caused the enhancement of proliferation and migration, probably by mediating AA release and reactive oxygen species (ROS) production.


Assuntos
Ácido Araquidônico/farmacologia , Peróxido de Hidrogênio/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Fenilefrina/farmacologia , Receptores Adrenérgicos alfa 1/fisiologia , Animais , Ácido Araquidônico/metabolismo , Catalase/metabolismo , Divisão Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , DNA/biossíntese , Músculo Liso Vascular/metabolismo , Coelhos
19.
Biochem Biophys Res Commun ; 232(1): 1-4, 1997 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-9125108

RESUMO

Transforming growth factor-beta (TGF-beta) has been implicated in mediating the growth of vascular smooth muscle cells (VSMCs) after vascular injury. In this study, we examined the mechanism underlying the growth-modulating effects of TGF-beta in confluent VSMCs. Stimulation of rat VSMC by TGF-beta decreased both their catalase activity and glutathione peroxidase activity in a dose-dependent manner. In mitogenesis assays using the confluent cells, TGF-beta was not a direct mitogen for VSMC, but potentiated the stimulatory effect of platelet-derived growth factor (PDGF)-BB. This enhancement of mitogenesis was blunted by the addition of the scavenging enzyme catalase or the chemical antioxidant N-acetyl-L-cysteine. In summary, TGF-beta enhances the mitogenic effect response of PDGF-BB, largely depending on the dysregulation of catalase activity and glutathione peroxidase activity by TGF-beta.


Assuntos
Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Músculo Liso Vascular/metabolismo , Fator de Crescimento Derivado de Plaquetas/fisiologia , Fator de Crescimento Transformador beta/fisiologia , Animais , Antioxidantes/farmacologia , Células Cultivadas , Mitógenos/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/enzimologia , Ratos , Timidina/metabolismo , Trítio
20.
Eur J Pharmacol ; 336(2-3): 267-73, 1997 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-9384242

RESUMO

We studied the effects of phenylephrine-stimulated proliferation and migration of vascular smooth muscle cells and the role of 12-lipoxygenase-mediated pathways under normal as well as high glucose conditions. Phenylephrine-induced increases in cellular proliferation and migration were attenuated by the specific 12-lipoxygenase inhibitor baicalein. In contrast, neither of the cyclo-oxygenase inhibitors, indomethacin or ibuprofen, had any effect. Direct addition of the 12-lipoxygenase product, 12-S-hydroxyeicosatetraenoic acid (12-HETE), increased the proliferation and migration of vascular smooth muscle cells treated with both phenylephrine and nordihydroguaiaretic acid. Furthermore, we observed that phenylephrine induced greater increases in the proliferation and migration of vascular smooth muscle cells and also that the 12-lipoxygenase inhibitor prevented the enhancement of proliferation and migration of vascular smooth muscle cells induced by phenylephrine in the presence of high glucose (25 mmol/l). These results suggest that 12-lipoxygenase activation plays a key role in phenylephrine-induced responses of vascular smooth muscle cells under normal and hyperglycemic conditions. 12-lipoxygenase may be a good pharmacological target for treatment of vascular disease of hypertension and diabetes mellitus.


Assuntos
Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/farmacologia , Lipoxigenase/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Inibidores de Ciclo-Oxigenase/farmacologia , Ativação Enzimática , Inibidores de Lipoxigenase/farmacologia , Músculo Liso Vascular/enzimologia , Fenilefrina/farmacologia , Coelhos
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