Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Int J Cosmet Sci ; 42(6): 590-595, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32634864

RESUMO

A sensory descriptive method is used by the industries to characterize their various products under development. The sensory panelists are recruited through some general criteria suggested in International Standard Sensory Analysis - General guidelines for the selection, training and monitoring of selected assessors and expert sensory assessors [5] but for hair product evaluation, some hair criteria should also be considered, as a major challenge lied in the difficulty to recruit panelists. Such an issue led us to find practical solutions to make this recruitment easier. Among others, one possible solution was to restrict some requirements in the characteristics of hair. This study aimed at checking if a hair type diversification on either sensitization or curliness could influence the sensory perception of shampoos, and, if so, to which extent. This study demonstrates that, for a shampoo trained panel, the evaluation is impacted by the hair curliness but is not impacted by the hair sensitization level.


Une méthode de description des sensations est utilisée par les industries pour caractériser leurs différents produits en cours de développement. Des membres sont recrutés pour un panel en se basant sur certains critères généraux suggérés dans la Norme Internationale d'Analyse sensorielle - Directives générales pour la sélection, la formation et la supervision des évaluateurs sélectionnés et des évaluateurs sensoriels experts [5], mais pour l'évaluation des cheveux, certains critères doivent également être pris en compte, car une des principales difficultés consiste à recruter des panélistes. Ce problème nous a obligé de trouver des solutions pratiques pour faciliter ce recrutement. Entre autres, une solution possible était de limiter certaines exigences au niveau des caractéristiques des cheveux. Cette étude vise à vérifier si la diversité au niveau de la sensibilité ou de la frisure de la chevelure pourrait influencer la perception sensorielle des shampooings, et, si c'est le cas, dans quelle mesure. Cette étude démontre que, pour une palette de 6 shampooings développés, l'évaluation est impactée par la frisure de la chevelure7mais n'est pas impactée par le niveau de sensibilité.


Assuntos
Preparações para Cabelo , Cabelo , Humanos
2.
Acta Neurol Scand ; 129(4): 276-81, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24032478

RESUMO

OBJECTIVES: In the last decade, increasing evidence suggests a key role of adenosine in Parkinson's disease (PD) and A2A adenosine receptors (A2A ARs) as an important pharmacological target in PD. An overexpression of A2A ARs has been found in putamen and in peripheral blood cells of PD patients. The primary aim of this study was to verify whether the alterations in A2A ARs in lymphocytes of PD subjects correlate with disease severity. MATERIAL AND METHODS: A consecutive sample of PD patients was enrolled. A clinical examination and a face-to-face interview were carried out. A2A ARs were investigated to verify the affinity and receptor density in lymphocyte membranes. The data were compared with those found in healthy controls. Moreover, the correlation between A2A AR density and affinity and clinical variables was evaluated in PD patients. RESULTS: In human lymphocyte membranes from PD patients, an increase in A2A AR density and a decrease in A2A AR affinity were found if compared with healthy subjects. A statistically significant correlation between the A2A AR density or affinity and specific clinical parameters as motor and cognitive impairment was detected. Patients with higher A2A AR density and lower affinity were more likely to exhibit motor complications. CONCLUSIONS: Parkinson's disease patients show an A2A AR upregulation in lymphocyte membranes if compared with healthy subjects. The correlation found between A2A AR density or affinity and clinical parameters highlights the central role of A2A AR modulation in the pharmacological treatment for PD and could suggest the putative role of A2A AR as a candidate biomarker of PD severity.


Assuntos
Doença de Parkinson/complicações , Doença de Parkinson/patologia , Receptor A2A de Adenosina/metabolismo , Agonistas do Receptor A2 de Adenosina/farmacocinética , Idoso , Progressão da Doença , Relação Dose-Resposta a Droga , Discinesias/etiologia , Feminino , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Ligação Proteica/efeitos dos fármacos , Estatísticas não Paramétricas , Triazinas/farmacocinética , Triazóis/farmacocinética , Trítio/farmacocinética
3.
J Cell Physiol ; 227(6): 2461-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21830213

RESUMO

Synovial fibroblasts (SFs) contribute to the development of osteoarthritis (OA) by the secretion of a wide range of pro-inflammatory mediators, including cytokines and lipid mediators of inflammation. Previous studies suggest that electromagnetic fields (EMFs) may represent a potential therapeutic approach to limit cartilage degradation and control inflammation associated to OA, and that they may act through the adenosine pathway. Therefore, we investigated whether EMFs might modulate inflammatory activities of human SFs from OA patients (OASFs) treated with interleukin-1ß (IL-1ß), and the possible involvement of adenosine receptors (ARs) in mediating EMF effects. EMF exposure induced a selective increase in A(2A) and A(3) ARs. These increases were associated to changes in cAMP levels, indicating that ARs were functionally active also in EMF-exposed cells. Functional data obtained in the presence of selective A(2A) and A(3) adenosine agonists and antagonists showed that EMFs inhibit the release of prostaglandin E(2) (PGE(2)) and the proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), while stimulating the release of interleukin-10 (IL-10), an antinflammatory cytokine. These effects seem to be mediated by the EMF-induced upregulation of A(2A) and A(3) ARs. No effects of EMFs or ARs have been observed on matrix degrading enzyme production. In conclusion, this study shows that EMFs display anti-inflammatory effects in human OASFs, and that these EMF-induced effects are in part mediated by the adenosine pathway, specifically by the A(2A) and A(3) AR activation. Taken together, these results open new clinical perspectives to the control of inflammation associated to joint diseases.


Assuntos
Citocinas/metabolismo , Dinoprostona/metabolismo , Campos Eletromagnéticos , Fibroblastos/metabolismo , Mediadores da Inflamação/metabolismo , Osteoartrite do Quadril/metabolismo , Receptores Purinérgicos P1/metabolismo , Membrana Sinovial/metabolismo , Proteínas ADAM/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Fibroblastos/patologia , Humanos , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Metaloproteinases da Matriz/metabolismo , Pessoa de Meia-Idade , Osteoartrite do Quadril/genética , Osteoartrite do Quadril/imunologia , Osteoartrite do Quadril/patologia , Agonistas do Receptor Purinérgico P1/farmacologia , Antagonistas de Receptores Purinérgicos P1/farmacologia , RNA Mensageiro/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor A3 de Adenosina/metabolismo , Receptores Purinérgicos P1/efeitos dos fármacos , Receptores Purinérgicos P1/genética , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/imunologia , Membrana Sinovial/patologia
4.
Osteoarthritis Cartilage ; 17(2): 252-62, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18640059

RESUMO

OBJECTIVE: To investigate the role of adenosine analogs and electromagnetic field (EMF) stimulation on prostaglandin E(2) (PGE(2)) release and cyclooxygenase-2 (COX-2) expression in bovine synovial fibroblasts (SFs). METHODS: SFs isolated from synovia were cultured in monolayer. Saturation and binding experiments were performed by using typical adenosine agonists: N6-cyclohexyladenosine (CHA, A(1)), 2-[p-(2-carboxyethyl)-phenetyl-amino]-5'-N-ethylcarboxamidoadenosine (CGS 21680, A(2A)), 5'-N-ethylcarboxamidoadenosine (NECA, non-selective), N6-(3-iodobenzyl)2-chloroadenosine-5'-N-methyluronamide (Cl-IB-MECA, A(3)). SFs were treated with TNF-alpha (10 ng/ml) and lipopolysaccharide (LPS) (1 microg/ml) to activate inflammatory response. Adenosine analogs were added to control and TNF-alpha- or LPS-treated cultures both in the absence and in the presence of adenosine deaminase (ADA) which is used to deplete endogenous adenosine. Parallel cultures were exposed to EMFs (75 Hz, 1.5 mT) during the period in culture (24h). PGE(2) release was measured by immunoassay. COX-2 expression was evaluated by RT-PCR. RESULTS: TNF-alpha and LPS stimulated PGE(2) release. All adenosine agonists, except for Cl-IB-MECA, significantly inhibited PGE(2) production. EMFs inhibited PGE(2) production in the absence of adenosine agonists and increased the effects of CHA, CGS 21680 and NECA. In ADA, the inhibition on PGE(2) release induced by CHA, CGS and NECA was stronger than in the absence of ADA and the EMF-inhibitory effect was lost. Changes in PGE(2) levels were associated to modification of COX-2 expression. CONCLUSIONS: This study supports anti-inflammatory activities of A(1) and A(2A) adenosine receptors and EMFs in bovine SFs. EMF activity appears mediated by an EMF-induced up-regulation of A(2A) receptors. Biophysical and/or pharmacological modulation of adenosine pathways may play an important role to control joint inflammation.


Assuntos
Adenosina/agonistas , Dinoprostona/metabolismo , Campos Eletromagnéticos , Fibroblastos/metabolismo , Líquido Sinovial/metabolismo , Adenosina/farmacologia , Animais , Ligação Competitiva , Bovinos , Células Cultivadas , Colforsina/farmacologia , Ciclo-Oxigenase 2/metabolismo , Relação Dose-Resposta a Droga , Fibroblastos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Receptores Purinérgicos P1/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Líquido Sinovial/citologia , Líquido Sinovial/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
5.
Science ; 204(4390): 306-9, 1979 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-155309

RESUMO

Active transport of calcium into inside-out vesicles of red blood cell membranes was stimulated equally by (i) the purified protein activator of calcium-activated, magnesium-dependent adenosinetriphosphatase isolated from red cell hemolyzates and (ii) calmodulin, a protein activator of cylic nucleotide phosphodiesterase isolated from bovine brain. The results provide further evidence for the identity of red blood cell activator and calmodulin and show that this cytoplasmic protein may participate in the regulation of plasma membrane calcium transport.


Assuntos
ATPases Transportadoras de Cálcio/sangue , Cálcio/metabolismo , Calmodulina/farmacologia , Proteínas de Transporte/farmacologia , Membrana Eritrocítica/enzimologia , Eritrócitos/enzimologia , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Calmodulina/sangue , Bovinos , Sistema Livre de Células , Citosol/fisiologia , Ativação Enzimática/efeitos dos fármacos , Estimulação Química , Troponina/farmacologia
6.
Osteoarthritis Cartilage ; 16(11): 1421-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18448363

RESUMO

OBJECTIVE: The aim of the present study is that of characterizing, for the first time in a quantitative way, from a biochemical, physico chemical and functional point of view P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes. The affinity and the potency of typical purinergic ligands were studied through competition binding experiments and their role in modulating chondrocyte actvities was investigated by analyzing nitric oxide (NO) and prostaglandin E2 (PGE(2)) release. METHODS: Saturation, competition binding experiments, western blotting and immunohistochemistry assays on the P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes were performed. Thermodynamic analysis of the P2X(1) and P2X(3) purinergic binding was studied to investigate the forces driving drug-receptor coupling. In the functional assays (NO and PGE(2) release) the potency of purinergic agonists and antagonists was evaluated. RESULTS: Bovine chondrocytes expressed P2X(1) and P2X(3) purinergic receptors and thermodynamic parameters indicated that purinergic binding is enthalpy- and entropy-driven for agonists and totally entropy-driven for antagonists. Typical purinergic agonists such as adenosine 5'-triphosphate (ATP) and alpha,beta-methyleneATP were able to increase NO and PGE(2) release. A purinergic antagonist, A317491, was able to block the stimulatory effect on functional experiments mediated by the agonists. CONCLUSIONS: These data demonstrate for the first time the presence of functional P2X(1) and P2X(3) purinergic receptors in bovine chondrocytes. Agonists and antagonists are thermodynamically discriminated and are able to modulate functional responses such as NO and PGE(2) release. These results suggest the potential role of novel purinergic antagonists in the treatment of pathophysiological diseases linked to the inflammation and involved in articular cartilage resorption.


Assuntos
Condrócitos/metabolismo , Dinoprostona/metabolismo , Óxido Nítrico/metabolismo , Receptores Purinérgicos P2/metabolismo , Animais , Ligação Competitiva , Biomarcadores/metabolismo , Bovinos , Células Cultivadas , Receptores Purinérgicos P2X , Receptores Purinérgicos P2X3
7.
J Biomed Mater Res A ; 105(2): 510-520, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27667508

RESUMO

Wear-particle osteolysis affects prosthesis survival leading to implant loosening up to 70% of revisions. Therapeutic strategies are increasing, however alternative testing methods to experimentally evaluate such treatments are lacking. The aim of this study was to reproduce an in vitro osteolysis model recapitulating the events that, starting from the exposure of macrophages to polyethylene, lead to the establishment of osteoclastogenesis and inflammation. Responses to polyethylene, at 3 and 7 days, in a macrophage cell line, RAW 264.7, were determined by DNA quantification, immunofluorescence, pit assay, gene expression, cytokine production and NF-kB activation. Results showed that 3 days exposure to particles could induce a significant production of Tumor Necrosis Factor alpha (p < 0.0005) and Prostaglandin E2 (p < 0.005) compared to controls. Particles also induced macrophages to spontaneously differentiate into mature and active osteoclasts, in terms of identification of multinucleated cells by Phalloidin staining and by the analysis of osteoclast-specific gene markers. In particular, at 3 days polyethylene induced a significant up-regulation of Nuclear Factor of Activated T-cells, cytoplasmic 1, Receptor Activator of Nuclear factor Kappa-B and Receptor Activator of Nuclear Factor Kappa-B Ligand genes (p < 0.0005) compared to controls. At protein level, the particles induced a significant increase of Receptor Activator of Nuclear Factor Kappa-B Ligand at day 7 over controls (p < 0.0005). Osteoclasts were capable to resorb bone even in absence of differentiating factors. The possible mechanism, beside spontaneous osteoclastogenesis mediated by wear debris, was identified in an autocrine up-regulation of Receptor activator of nuclear factor kappa-B ligand gene expression and protein synthesis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 510-520, 2017.


Assuntos
Interface Osso-Implante , Osteoclastos/metabolismo , Osteólise/metabolismo , Polietilenos , Animais , Antígenos de Diferenciação/biossíntese , Técnicas de Cocultura , Camundongos , Osteoclastos/patologia , Osteólise/patologia , Polietilenos/química , Polietilenos/farmacologia , Células RAW 264.7 , Fatores de Tempo
8.
Biochim Biophys Acta ; 1106(1): 63-70, 1992 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-1316165

RESUMO

An assay of the Ca pump ATPase of intact human RBCs is described in a companion paper (Wu, L., Hinds, T. R. and Vincenzi, F. F. (1992) Biochim. Biophys. Acta 1106, 56-62). The assay is based on the rapid loss of ATP in RBCs that occurs when the cells are exposed to the ionophore, A23187, in the presence of Ca. An unexpected finding was that the initial loss of ATP follows pseudo-first-order kinetics. This was unexpected because the ATP content of RBCs is somewhat higher than the Km of the Ca pump for ATP. Thus, the initial loss of ATP would be expected to follow zero-order kinetics; at least if the Ca pump ATPase operated with Michaelis kinetics. We performed a series of computer simulations of the Ca pump ATPase to investigate the possible cause of the unexpected pseudo-first-order behavior. The results confirmed that the data can not be accounted for by Michaelis kinetics of the Ca pump ATPase. Possible effects of adenylate kinase were tested and were also not found to account for the pseudo-first-order behavior of an ATPase operating with Michaelis kinetics. The enzymatic properties of the Ca pump ATPase were re-examined. It was found that the Ca pump ATPase exhibits positive cooperativity toward ATP. The apparent cooperativity was 1.91. In simulations it was found that positive cooperativity of the Ca pump ATPase in the range of 1.5 to 2.0 could account for the pseudo-first-order behavior. Excellent fit of the simulation data to first-order behavior was true with or without any contribution from adenylate kinase. Rate constants of ATP loss were thus examined using cooperativity of 2.0. Over a wide range the rate constant of the loss of ATP was directly proportional to the assumed Vmax of the Ca pump ATPase, but only if the data were limited to loss of less than 67% of the initial ATP. It is suggested, therefore, that the rate constant for the initial loss of ATP in intact RBCs, as stimulated by the ionophore A23187, can be taken as a measure of the capacity of the Ca pump ATPase.


Assuntos
ATPases Transportadoras de Cálcio , Eritrócitos/metabolismo , Difosfato de Adenosina/metabolismo , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/metabolismo , Ativação Enzimática , Eritrócitos/enzimologia , Humanos , Cinética , Modelos Teóricos
9.
Biochim Biophys Acta ; 471(1): 49-58, 1977 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-144528

RESUMO

1. Membranes prepared from human erythrocytes hemolyzed in isosmotic (310 imosM) imidazole buffer, pH 7.4, show enhanced and stabilized (Ca2+ + Mg2+)-ATPase activity compared with membranes prepared from erythrocytes hemolyzed in hypotonic (20 imosM) phosphate or imidazole buffer, pH 7.4. 2. Exposure of intact erythrocytes or well-washed erythrocyte membranes to isosmotic imidazole does not cause enhanced (Ca2+ + Mg2+)-ATPase activity. 3. Exposure of erythrocyte membranes, in the presence of isosmotic imidazole, to the supernatant of erythrocyte hemolysis or to a partially purified endogenous (Ca2+ + Mg2+)-ATPase activator, promotes enhanced (Ca2+ + Mg2+)-ATPase activity. Under appropriate conditions, NaCl can be shown to substitute for imidazole. The results demonstrate that imidazole does not act directly on the erythrocyte membrane but rather by promoting interaction between an endogenous (Ca2+ + Mg2+)-ATPase activator and the erythrocyte membrane.


Assuntos
Adenosina Trifosfatases/sangue , Membrana Eritrocítica/enzimologia , Eritrócitos/enzimologia , Imidazóis/farmacologia , Soluções Tampão , Cálcio/sangue , Ativação Enzimática/efeitos dos fármacos , Membrana Eritrocítica/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Cinética , Magnésio/farmacologia , Temperatura
10.
Biochim Biophys Acta ; 471(1): 59-66, 1977 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-144529

RESUMO

1. Activity of the (Ca2+ + Mg2+)-ATPase of erythrocyte membrane may be enhanced by a cytoplasmic protein activator. The presence of Ca2+ is necessary for the ionic strength-dependent interaction between the erythrocyte membrane and the activator. This is true no matter the purity of activator (unfractionated hemolysis supernatant or partially purified activator) or the major source of ionic strength (imidazole or NaCl). 2. When the endogenous activator enhances (Ca2+ + Mg2+)-ATPase activity of the erythrocyte membrane, there is a physical association between activator and membrane. This association is not disrupted by a decrease in ionic strength to 0.005 but is reversed by exposure to 5 mM ethyleneglycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid. 3. Activator binding necessary for enhancement of (Ca2+ + Mg2+)-ATPase activity may occur during preparation of membranes or during incubation for assay of ATPase.


Assuntos
Adenosina Trifosfatases/sangue , Cálcio/farmacologia , Membrana Eritrocítica/enzimologia , Eritrócitos/enzimologia , Imidazóis/farmacologia , Proteínas Sanguíneas/fisiologia , Soluções Tampão , Cálcio/sangue , Fracionamento Celular , Ácido Egtázico/farmacologia , Ativação Enzimática/efeitos dos fármacos , Membrana Eritrocítica/ultraestrutura , Humanos , Cinética , Magnésio/farmacologia
11.
Biochim Biophys Acta ; 1106(1): 56-62, 1992 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-1316164

RESUMO

An assay for the Ca pump ATPase of intact human red blood cells (RBCs) was developed. The assay utilized a small volume (typically 10 microliters) of packed RBCs in 1 ml of a buffer of known composition. The assay was based on the exposure of intact RBCs to the ionophore, A23187, in the presence of Ca. Such exposure caused a rapid degradation of ATP in RBCs. This degradation process is modeled in a numerical simulation in a companion paper (Vincenzi, F. F. and Hinds, T. R. (1992) Biochim. Biophys. Acta 1105, 63-70). The loss of ATP followed pseudo-first-order kinetics, and the rate constants for ATP degradation was taken as a measure of the capacity of the Ca pump ATPase. A number of variables were examined to optimize the activity of the ATPase. These variables included the concentrations of Ca and A23187. Because A23187 can promote loss of cellular Mg, it was necessary to include MgCl2 in the incubation medium to optimize ATPase activity. Likewise, it was determined that inclusion of iodoacetic acid optimized the rate of ATP loss, presumably by preventing the resynthesis of ATP from ADP and inorganic phosphate. Cobalt inhibited the ionophore-dependent loss of ATP by apparent competition with Ca for binding to A23187. Results of many assays demonstrated substantial differences in the rate constant for ATP loss in RBCs from different individuals. RBCs were selected according to density. Density associated loss of Ca pump ATPase activity was observed both by the intact RBC assay, and by assay of Ca pump ATPase activity in saponin lysates of RBCs. The correlation coefficient between the two assays was 0.93. It is suggested that the rate constant for ATP loss in intact RBCs exposed to A23187 and Ca can be taken as a measure of the Ca pump ATPase activity. This may be useful when isolated membrane ATPase assays fail (e.g., dog RBCs). The intact cell assay can also be carried out on very small volumes of cells and may be of particular value when RBC volumes are limited.


Assuntos
Adenosina Trifosfatases/metabolismo , ATPases Transportadoras de Cálcio , Eritrócitos/enzimologia , Trifosfato de Adenosina/metabolismo , Calcimicina/farmacologia , Cátions Bivalentes , Membrana Eritrocítica/enzimologia , Eritrócitos/efeitos dos fármacos , Humanos , Técnicas In Vitro , Cinética , Magnésio/metabolismo
12.
Biochim Biophys Acta ; 1153(1): 67-76, 1993 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-8241252

RESUMO

Incubation of human red blood cells (RBCs) with t-butyl hydroperoxide (tBHP) resulted in inhibition of the Ca-pump ATPase. This was demonstrated using an assay of the Ca-pump ATPase activity in intact RBCs. In this assay, activity of the Ca-pump ATPase is expressed as the rate constant of the initial loss of ATP in RBCs exposed to Ca and A23187. Pseudo-first-order rate constants (Ca-pump ATPase rate constants) were lower in the presence of tBHP versus controls. Incubation of RBCs with tBHP resulted in both a time- and concentration-dependent inhibition of the Ca-pump ATPase (IC50 approximately 1 mM). Incubation of RBCs with tBHP also resulted in decreased oxyhemoglobin, increased methemoglobin and increased thiobarbituric acid reactive substances (TBARS). GSH levels were significantly lower in the presence of tBHP. GSH fell from a control value of 2.2 mmol/l RBC to 0.46 mmol/l RBC after incubation with 0.25 mM tBHP for 15 min. Both butylated hydroxytoluene and stobadine prevented the formation of TBARS and were partially effective in protecting the Ca-pump ATPase from tBHP-induced inhibition. Dithiothreitol was completely effective in preventing the tBHP-induced formation of TBARS as well as inhibition of the Ca-pump ATPase. However, when added after exposure to tBHP, dithiothreitol was unable to restore Ca-pump ATPase activity completely. An activity of dithiothreitol independent of enzymic thiol group reduction was apparent. In the presence of mercaptosuccinate, a potent inhibitor of glutathione peroxidase, the ability of dithiothreitol to protect the Ca-pump ATPase from tBHP-induced inhibition was abolished. Therefore, protection by dithiothreitol may be afforded by its ability to replenish GSH from oxidized glutathione, thus allowing glutathione peroxidase to metabolize tBHP. These results may be interpreted to suggest that inhibition of the Ca-pump ATPase in intact RBCs occurs as a result of tBHP-induced oxidant stress and subsequent lipid peroxidation which can be prevented by certain antioxidants including butylated hydroxytoluene, stobadine, and thiol-containing compounds such as dithiothreitol. These findings provide further insight into the mode of action of hydroperoxides and certain reactive oxygen species that have been implicated in oxidative stress associated with various pathological conditions. The importance of the GSH/glutathione peroxidase system in metabolizing organic hydroperoxides is also demonstrated.


Assuntos
ATPases Transportadoras de Cálcio/antagonistas & inibidores , Eritrócitos/enzimologia , Glutationa Peroxidase/metabolismo , Peróxidos/farmacologia , Carbolinas/farmacologia , Ditiotreitol/farmacologia , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Sequestradores de Radicais Livres , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Oxiemoglobinas/análise , Peróxidos/antagonistas & inibidores , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Fatores de Tempo , terc-Butil Hidroperóxido
13.
Biochim Biophys Acta ; 981(2): 337-42, 1989 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-2525052

RESUMO

Compound 48/80 (48/80), a mixture of polycationic compounds was fractionated using affinity chromatography on calmodulin-Sepharose. Unfractionated 48/80 and various fractions were tested for their potential inhibitory effects on ATPase activities of isolated human red blood cell membranes. ATPase activities tested included: Mg2+-ATPase, the Na+/K+-pump ATPase, and the Ca2+-pump ATPase in both its basal (calmodulin-independent) and calmodulin-activated state. Neither 48/80 nor its various fractions were very potent or efficacious inhibitors of the Mg2+-ATPase or the Na+/K+-pump ATPase. In agreement with previous reports, 48/80 was found to be an inhibitor of the calmodulin-activated Ca2+-pump ATPase. By contrast, we found that unfractionated, as well as some fractionated, material inhibited both the basal (calmodulin-independent) and calmodulin-activated Ca2+-pump ATPase activity. A fraction designated as Fraction III bound to calmodulin-Sepharose in the presence of Ca2+ and low salt and was eluted in the absence of Ca2+ and 0.15 M NaCl. By gel filtration, Fraction III had an apparent average molecular weight of 2064 (1320 for unfractionated material). Fraction III was the most potent inhibitor of the Ca2+-pump ATPase with IC50 values for the basal and calmodulin-activated forms of the enzyme of 0.6 and 1.2 micrograms/ml, respectively. Inhibition by Fraction III was cooperative with n apparent values of 2.4 and 5.7, respectively, for the basal and calmodulin-activated forms of the enzyme. Thus, binding of 48/80 constituents to calmodulin can not fully account for the observed data. Direct interaction of 48/80 constituent(s) with the enzyme and/or the lipid portion of the membrane is suggested.


Assuntos
ATPases Transportadoras de Cálcio/antagonistas & inibidores , Calmodulina/farmacologia , p-Metoxi-N-metilfenetilamina/farmacologia , Transporte Biológico Ativo/efeitos dos fármacos , ATPase de Ca(2+) e Mg(2+)/metabolismo , ATPases Transportadoras de Cálcio/sangue , Ativação Enzimática , Membrana Eritrocítica/enzimologia , Humanos , Técnicas In Vitro , Cinética , p-Metoxi-N-metilfenetilamina/análise
14.
Neuropharmacology ; 95: 68-82, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25769232

RESUMO

JWH-018 is a synthetic CB1 and CB2 agonist illegally marketed as products named "Spice" or "herbal blend" for its psychoactive effects which are much higher than those produced by cannabis. In the last year, the European Monitoring Centre for Drugs and Drug Addiction reported to the Italian National Early Warning System the seizure of plant material containing new halogenated derivatives of JWH-018 (JWH-018 Cl and JWH-018 Br). The present study aimed to investigate the in vitro and in vivo activity of these two new synthetic cannabinoids in mice. In vitro competition binding experiments performed on mouse and human CB1 receptors revealed a high affinity and potency of the halogenated compounds. Synthetic cannabinoids (0.01-6 mg/kg i.p.) impaired motor activity and induced catalepsy in mice and their effects were more severe with respect to those evoked by Δ(9)-THC. Moreover, they increased the mechanical and thermal pain threshold and induced a marked hypothermia. It is interesting to note that whereas high doses of JWH-018 cause seizures, myoclonia and hyperreflexia, the halogenated compounds, in particular JWH-018Br, were less effective. Behavioral and neurological changes were prevented by the selective CB1 receptor antagonist AM 251. These data demonstrate for the first time that JWH-018 Cl and JWH-018 Br act similarly to JWH-018 while inducing less convulsive episodes and myoclonias. These data support the hypothesis that the halogenated compounds may have been introduced onto market to produce similar intoxicating effects as JWH-018 while causing less side effects.


Assuntos
Agonistas de Receptores de Canabinoides/metabolismo , Agonistas de Receptores de Canabinoides/farmacologia , Indóis/metabolismo , Indóis/farmacologia , Naftalenos/metabolismo , Naftalenos/farmacologia , Animais , Ligação Competitiva , Células CHO , Agonistas de Receptores de Canabinoides/química , Agonistas de Receptores de Canabinoides/toxicidade , Canabinoides/química , Canabinoides/farmacologia , Canabinoides/toxicidade , Catalepsia/induzido quimicamente , Cricetulus , Halogenação , Humanos , Hipotermia/induzido quimicamente , Indóis/química , Indóis/toxicidade , Masculino , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Naftalenos/química , Naftalenos/toxicidade , Limiar da Dor/efeitos dos fármacos , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/genética , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Reflexo Anormal/efeitos dos fármacos , Convulsões/induzido quimicamente
15.
Cell Calcium ; 2(4): 387-409, 1981 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7042098

RESUMO

Calmodulin (CaM) is a major intracellular receptor for Ca2+. CaM is thus a crucial receptor to consider in pharmacological modification of cellular activity. Potential mechanisms by which drugs may modify CaM effectiveness are considered in the context of its interaction with Ca2+ and in turn with its various effectors. Some examples of established drug mechanisms are considered. A wide range of chemical compounds representing diverse pharmacological classes are anti-CaM under some conditions. No simple relationships have been established between molecular level events and therapeutic applicability of anti-CaM compounds.


Assuntos
Proteínas de Ligação ao Cálcio/antagonistas & inibidores , Calmodulina/antagonistas & inibidores , Cálcio/antagonistas & inibidores , Cálcio/metabolismo , Calmodulina/análise , Calmodulina/fisiologia , Proteínas de Ligação a Calmodulina , Proteínas de Transporte/metabolismo , Humanos , Psicotrópicos/metabolismo , Receptores de Droga/efeitos dos fármacos
16.
Cell Calcium ; 6(3): 265-79, 1985 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2410131

RESUMO

The calcium selective ionophore, ETH 1001, and the divalent cation ionophore, A23187, promoted Ca2+ flux across RBC membranes under various experimental conditions. ETH 1001 did not promote the passive movement of Mg2+ whereas A23187 did. The results confirm the potential application of ETH 1001 as a Ca2+ selective ionophore for biological membranes.


Assuntos
Cálcio/sangue , Diaminas/farmacologia , Membrana Eritrocítica/metabolismo , Canais Iônicos/efeitos dos fármacos , Calcimicina/farmacologia , Humanos , Técnicas In Vitro , Magnésio/sangue , Fatores de Tempo
17.
Cell Calcium ; 3(6): 545-59, 1982 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6219744

RESUMO

A variety of presumed anti-calmodulin (anti-CaM) drugs was tested for their potential inhibitory effects on the isolated, purified and reconstituted Ca2+-pump ATPase of human red blood cell membranes. Anti-CaM drugs inhibited the Ca2+-pump ATPase both in the absence and presence of added CaM. Qualitatively similar inhibition was observed in two different ATPase assay systems. In asolectin vesicles in the absence of added CaM trifluoperazine (TFP), N-(6-aminohexyl)-5-chloro-1-naphthalene- sulfonamide (W-7), vinblastine, dibucaine, imipramine, propranolol and dimethylpropranolol (UM-272) were all inhibitory. Potency of anti-CaM drugs was generally greater on the enzyme reconstituted in asolectin vesicles than on the enzyme reconstituted in phosphatidylcholine vesicles, either in the presence or absence of CaM. The results emphasize that anti-CaM drugs have actions other than to bind to CaM. Possible direct interaction of amphipathic cationic anti-CaM drugs with the Ca2+-pump ATPase and/or its lipid environment is suggested.


Assuntos
Proteínas de Ligação ao Cálcio/antagonistas & inibidores , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Calmodulina/antagonistas & inibidores , Eritrócitos/enzimologia , ATPases Transportadoras de Cálcio/sangue , Calmodulina/fisiologia , Ativação Enzimática/efeitos dos fármacos , Membrana Eritrocítica/enzimologia , Humanos , Fosfatidilcolinas , Fosfolipídeos/farmacologia
18.
Hypertension ; 8(11): 1058-66, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2945785

RESUMO

Several operationally defined adenosine triphosphatase (ATPase) activities were determined in vitro in red blood cell lysates of normotensive or hypertensive humans: Mg2+-ATPase, Na+,K+-ATPase, and Ca2+ pump ATPase, the latter in the calmodulin-activated and basal states. Basal Ca2+ pump ATPase was defined as the Ca2+-activated ATPase resistant to 10(-4) M trifluoperazine. Subjects were part of a double-blind study in which treatment was divided into several phases: baseline (4 weeks), placebo or calcium (1 g elemental calcium/day, 8 weeks), placebo washout (4 weeks), placebo or calcium (1 g elemental calcium/day, 8 weeks). Irrespective of the phase of treatment, the basal Ca2+ pump ATPase activity in red blood cell lysates of 36 hypertensive subjects was significantly less than that in lysates from 18 normotensive subjects. Other ATPase activities did not differ significantly, although all ATPases tended to be decreased in hypertension. The data are consistent with previous reports of altered membrane Ca2+ binding and transport in hypertension, but the precise changes are not elucidated.


Assuntos
ATPase de Ca(2+) e Mg(2+)/sangue , ATPases Transportadoras de Cálcio/sangue , Eritrócitos/metabolismo , Hipertensão/sangue , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Cálcio/administração & dosagem , Humanos , Pessoa de Meia-Idade , Fósforo/metabolismo , Distribuição Aleatória
19.
Free Radic Biol Med ; 18(4): 655-67, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7750790

RESUMO

Human neutrophils, activated by phorbol myristate acetate in the presence of intact red blood cells (RBCs), caused inhibition of the Ca2+ pump ATPase of the RBCs and fragmentation of the enzyme as well as other membrane proteins. Inhibition of the Ca2+ pump ATPase of intact RBCs was directly related to the neutrophil concentration and the time of incubation. Ca2+ pump ATPase activity was partially protected by the addition of exogenous glutathione-glutathione peroxidase, but not by superoxide dismutase. The addition of sodium azide, a potent inhibitor of endogenous RBC catalase, enhanced inhibition of the Ca2+ pump ATPase of intact RBCs. Examination by SDS-polyacrylamide gel electrophoresis of membrane proteins isolated from RBCs preincubated with activated neutrophils showed gross changes in banding patterns as compared to controls. Thus, a significant amount of methemoglobin appeared to be associated with the membrane proteins, and, in general, protein bands appeared to be more diffuse and less defined than proteins in control lanes. In addition, there was an increase in the low molecular weight protein bands. Using a monoclonal antibody to the Ca2+ pump ATPase, it was shown that the 140 kDa band representing the Ca2+ pump ATPase decreased, with concomitant appearance of two low molecular weight bands running at 8.2 and 6.8 kDa in the membrane proteins from RBCs preincubated with activated neutrophils. The data are interpreted to suggest that inhibition of the Ca2+ pump ATPase in intact RBCs under these conditions occurred as a result of: neutrophil-derived superoxide, dismutation of superoxide, to H2O2, diffusion of H2O2 into RBCs, a Fenton type reaction between oxyhemoglobin, and H2O2 producing hydroxyl radical and/or a ferryl radical capable of promoting protein fragmentation of RBC membrane proteins, including the plasma membrane Ca2+ pump ATPase.


Assuntos
ATPases Transportadoras de Cálcio , Eritrócitos/fisiologia , Neutrófilos/fisiologia , Western Blotting , Células Cultivadas/efeitos dos fármacos , Radicais Livres , Humanos , Espécies Reativas de Oxigênio , Fatores de Tempo
20.
J Med Chem ; 19(1): 153-8, 1976 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-54426

RESUMO

Preparation of analogs of 4-[N-(3-chlorophenyl) carbamoyloxy]-2-butynyltrimethylammonium chloride [1 (McN-A-343)], cis- and trans-4-[N-(4-chlorophenyl)carbamoyloxy]-2-butenyltrimethylammonium iodides (5 and 6), and the corresponding epoxides and cyclopropanes is reported. Pharmacological testing for ganglion-stimulating activity demonstrated that the trans olefin 6 and trans epoxide 8 have properties similar to 1, while the trans cyclopropane analog 10 was inactive. All cis compounds were inactive. The muscarinic ganglion-stimulating properties of the active compounds are interpreted in terms of similar fit at the receptor level by the alkyltrimethylammonium ion and the ether oxygen 5.7 A distant, as well as an electron-rich center midway between groups in the form of a double bond or unshared electron pairs. Comparison of smooth muscle and ganglion-stimulating properties of the compounds showed that trans epoxide 8 was the most selective for muscarinic ganglionic sites.


Assuntos
Cloreto de (4-(m-Clorofenilcarbamoiloxi)-2-butinil)trimetilamônio/síntese química , Estimulantes Ganglionares/síntese química , Parassimpatomiméticos/síntese química , Compostos de Amônio Quaternário/síntese química , Cloreto de (4-(m-Clorofenilcarbamoiloxi)-2-butinil)trimetilamônio/análogos & derivados , Cloreto de (4-(m-Clorofenilcarbamoiloxi)-2-butinil)trimetilamônio/farmacologia , Alcenos/síntese química , Alcenos/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Gatos , Ciclopropanos/síntese química , Ciclopropanos/farmacologia , Compostos de Epóxi/síntese química , Compostos de Epóxi/farmacologia , Íleo/efeitos dos fármacos , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Coelhos , Receptores Colinérgicos/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA