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1.
Eur Rev Med Pharmacol Sci ; 22(23): 8487-8496, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30556891

RESUMO

OBJECTIVE: Endometriosis is a debilitating disease characterized by chronic inflammation. The transporter multidrug resistance-associated protein 4 (MRP4/ABCC4) is expressed in human endometrial tissue; it is overexpressed in ectopic endometrial tissue, and is modulated by the anti-inflammatory lipid Lipoxin A4 (LXA4). Recently, it was demonstrated that aspirin induces platelet MRP4 over-expression, through genomic modulation in megakaryocytes. Since patients with endometriosis frequently use aspirin or other non-aspirin Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), the aim of this study was to verify whether aspirin and other NSAIDs enhance MRP4 expression in 12Z human endometriotic epithelial cells and whether this was peroxisome proliferator-activated receptor alpha (PPARa) dependent. MATERIALS AND METHODS: MRP4 and PPARa expression was analyzed by Q-RT-PCR using TaqMan® Master Mix and TaqMan® Assay Reagents (Life Technologies, Monza, Italy) and Western blot. RESULTS: In 12Z cells, aspirin and other NSAIDs enhanced MRP4 mRNA and protein expression; these treatments also induced PPARa expression. Aspirin and diclofenac-induced increases in MRP4 expression were not observed in cells where PPARa was knocked down using siRNA. NSAIDs-induced MRP4 expression was correlated with augmented PGE2 secretion, indicating functional relevance. CONCLUSIONS: MRP4 expression was increased in cells treated with NSAIDs and the nuclear receptor PPARa is involved. Elevated PGE2 levels in cell supernatants correlate with its increased transport by MRP4 after NSAID treatment. More importantly, we provide evidence that in endometriotic epithelial cells aspirin and non-aspirin NSAIDs treatments alter gene expression.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Endometriose/tratamento farmacológico , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , PPAR alfa/metabolismo , Aspirina/farmacologia , Linhagem Celular , Diclofenaco/farmacologia , Endometriose/metabolismo , Endométrio/metabolismo , Células Epiteliais/metabolismo , Feminino , Humanos , Itália , Lipoxinas/metabolismo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo
2.
Platelets ; 28(7): 728-730, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28287032

RESUMO

Heparin-induced thrombocytopenia (HIT) is a thrombotic complication of heparin therapy. The most used functional method for HIT diagnosis is serotonin release assay (SRA). A different functional method based on ATP release with luciferin/luciferase long-life and stable luminescent signal is used here, which is shown to be comparable for accuracy with SRA in both negative (patients 4Ts ≤3, and negative for both anti-PF4/heparin immunoassay and SRA) and positive (4Ts >3, and positive for both PF4/heparin antibodies and SRA) patients. Our results show that ATP release is higher in washed platelets activated by sera from positive patients than in platelets activated by sera from negative patients. In conclusion, we demonstrate that ATP release assay is a valid alternative method to SRA for the identification of pathogenic anti-PF4/heparin antibodies.


Assuntos
Trifosfato de Adenosina/sangue , Anticorpos/sangue , Anticoagulantes/efeitos adversos , Heparina/efeitos adversos , Medições Luminescentes/métodos , Serotonina/sangue , Trombocitopenia/diagnóstico , Adulto , Idoso , Anticoagulantes/imunologia , Plaquetas/imunologia , Plaquetas/patologia , Feminino , Luciferina de Vaga-Lumes/química , Seguimentos , Expressão Gênica , Heparina/imunologia , Humanos , Imunoensaio/métodos , Luciferases de Vaga-Lume/química , Masculino , Pessoa de Meia-Idade , Fator Plaquetário 4/genética , Fator Plaquetário 4/imunologia , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Trombocitopenia/imunologia
3.
Clin Exp Obstet Gynecol ; 43(3): 354-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27328490

RESUMO

PURPOSE OF INVESTIGATION: The aim of this study was to evaluate the correlation between endometriosis and pathologies on an immune basis for the possible involvement of the immune system in the pathogenesis of endometriosis. MATERIALS AND METHODS: In this retrospective study, data of 304 patients with endometriosis and 318 without endometriosis were collected in a uniform manner for both groups and inserted into two databases, respectively, for patients with and without endometriosis. The authors calculated the percentages of patients with allergies, autoimmune diseases, asthma in both groups, and later statistical analysis were performed with two different chi-square tests. RESULTS: The results obtained have shown that patients with endometriosis have a higher prevalence of allergies (p = 0.0003) and coexistence of both allergies and autoimmune diseases (p = 0.0274), compared to those without. CONCLUSIONS: The present study seems to support the possible association between endometriosis and allergic diseases.


Assuntos
Asma/epidemiologia , Doenças Autoimunes/epidemiologia , Endometriose/epidemiologia , Hipersensibilidade/epidemiologia , Adulto , Células Apresentadoras de Antígenos/imunologia , Asma/imunologia , Doenças Autoimunes/imunologia , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Comorbidade , Endometriose/imunologia , Feminino , Humanos , Hipersensibilidade/imunologia , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Interleucina-10/imunologia , Interleucina-12/imunologia , Itália/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Células Th1/imunologia , Células Th2/imunologia , Fator de Necrose Tumoral alfa/imunologia , Adulto Jovem
4.
Eur J Gynaecol Oncol ; 37(1): 122-5, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27048123

RESUMO

INTRODUCTION: Uterine sarcomas are rare and aggressive tumors. In some cases they can cause rupture of the uterus with or without clinical and radiological symptoms. Therefore, it is important to observe patients with clinical and/or radiological suspicion of sarcoma, even when there are no clinical manifestations. CASE REPORT: A 71-year old woman, who was under the authors' observation for pain in the right iliac fossa. The US and the CT scan showed an abdominal-pelvic mass.Laboratory tests showed a slight but progressive reduction of haemoglobin, which could not be explained by the clinical symptoms and by the results of the imaging tests. During the surgical intervention, a small amount of peritoneal fluid, an increased uterine volume, and a subverted anatomy were observed A haematoma was found in the uterus and this could explain the progressive reduction of haemoglobin and the very low presence of peritoneal effusion. CONCLUSION: The rupture of the uterus could not have been suspected as the patient did not have any type of symptoms, except for the slow and progressive reduction in the haemoglobin value. Therefore, it is important to observe patients with clinical and/or radiological suspicion of sarcoma, even when there are no clinical manifestations.


Assuntos
Hematoma/etiologia , Hemoglobinas/análise , Leiomiossarcoma/complicações , Neoplasias Uterinas/complicações , Idoso , Feminino , Humanos , Leiomiossarcoma/patologia , Neoplasias Uterinas/patologia
5.
World J Surg Oncol ; 14: 105, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27056684

RESUMO

BACKGROUND: The purpose of this study is to compare laparoscopy (LPS) and laparotomy (LPT), in terms of surgical outcomes, in elderly patients (>65 years) with adnexal masses. METHODS: We retrospectively reviewed a series of women older than 65 who had a diagnosis of adnexal masses. Then, all patients were divided into two different groups according to the type of surgery: 27 who underwent LPS (LPS group) and 24 who underwent LPT (LPT group). We took into consideration: age, comorbidity, histological diagnosis, surgery approach, and surgical outcome. Then, we calculated the percentages of all of these data and then χ (2) test and t-Student test were used to calculate the p value, to compare the two surgical techniques. A p value lower than 0.05 was considered to be statistically significant. RESULTS: At first, we evaluated the relation between the diagnosis and the surgery approach, and we obtained statistically significant results for serous cyst, adenocarcinoma serous/mucinous, and others, and the table highlights that some of the benign masses were mostly treated with LPS, while borderline and malignant masses were treated with LPT. Then, we evaluated the comorbidities of the patients, and we found that those cases had a significantly higher prevalence of cardiovascular disease and metabolic diseases. Finally, we compared the surgery outcome of LPS versus LPT surgeries for adnexal masses in elderly women, and there were statistically significant results for postoperative complications, number of patients who needed drainage, and number of days of hospitalization after surgery. CONCLUSIONS: Our results demonstrated that the patients who underwent LPS, compared to the patients who underwent LPT, have better outcomes in terms of postoperative complications (7.4 % with LPS and 37 % with LPT), number of patients who needed drainage (11.1 % with LPS and 62.5 % with LPT), and number of days of hospitalization after surgery, in term of mean (5 for LPS and 10.9 in term of LPT).


Assuntos
Doenças dos Anexos/cirurgia , Laparoscopia/métodos , Laparotomia/métodos , Neoplasias Ovarianas/cirurgia , Complicações Pós-Operatórias , Doenças dos Anexos/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Prognóstico , Estudos Retrospectivos
6.
Gynecol Endocrinol ; 31(4): 253-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25482873

RESUMO

INTRODUCTION: Assisted reproduction techniques are the frequent treatment of infertility. Despite the advances in science and technology, the management of poor responder patients is still considered as one of the most urgent problems. The lack of unified definition makes the management of the poor responder patients very difficult. The aim of this review is to examine and compare the different studies done about the problem of poor responder patients. METHODS: On an online research of MEDLINE/PUBMED, we found several studies on pharmacological treatment for poor responders' patients. RESULTS: Our review shows that in the years numerous therapies for the management of these patients who do not respond to ovarian stimulation have been evaluated and studied, but the main problem is the large and still not well-defined meaning of poor responder women. CONCLUSION: The management of the poor responder patients is very difficult. Currently, there is no any standard treatment for poor responder patients. Considering the importance of the problem, it is important to identify a diagnostic and therapeutic target. Our review shows that there are many studies with different therapeutic approaches which deserve further in-depth study to standardize diagnostic and therapeutic target.


Assuntos
Resistência a Medicamentos , Fármacos para a Fertilidade Feminina/farmacologia , Fertilização in vitro , Infertilidade Feminina/terapia , Indução da Ovulação/métodos , Ovulação/efeitos dos fármacos , Medicina de Precisão , Resistência a Múltiplos Medicamentos , Quimioterapia Combinada , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Fertilização in vitro/tendências , Humanos , Infertilidade Feminina/diagnóstico , Reserva Ovariana , Indução da Ovulação/tendências , Gravidez , Taxa de Gravidez , Terminologia como Assunto
7.
J Thromb Haemost ; 12(4): 550-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24460629

RESUMO

BACKGROUND: The activation of platelet CLEC-2 by podoplanin on lymphatic endothelial cells (LECs) has a critical role in prevention of mixing of lymphatic and blood vasculatures during embryonic development. Paradoxically, LECs release cAMP and cGMP-elevating agents, prostacyclin (PGI2 ) and nitric oxide (NO), respectively, which are powerful inhibitors of platelet activation. This raises the question of how podoplanin is able to activate CLEC-2 in the presence of the inhibitory cyclic nucleotides. OBJECTIVES: We investigated the influence of cyclic nucleotides on CLEC-2 signaling in platelets. METHODS: We used rhodocytin, CLEC-2 monoclonal antibody, LECs and recombinant podoplanin as CLEC-2 agonists on mouse platelets. The effects of the cyclic nucleotide-elevating agents PGI2 , forskolin and the NO-donor GSNO were assessed with light transmission aggregometry, flow cytometry, protein phosphorylation and fluorescent imaging of platelets on LECs. RESULTS: We show that platelet aggregation induced by CLEC-2 agonists is resistant to GSNO but inhibited by PGI2 . The effect of PGI2 is mediated through decreased phosphorylation of CLEC-2, Syk and PLCγ2. In contrast, adhesion and spreading of platelets on recombinant podoplanin, CLEC-2 antibody and LECs is not affected by PGI2 and GSNO. Consistent with this, CLEC-2 activation of Rac, which is required for platelet spreading, is not altered in the presence of PGI2 . CONCLUSIONS: The present results demonstrate that platelet adhesion and activation on CLEC-2 ligands or LECs is maintained in the presence of PGI2 and NO.


Assuntos
Plaquetas/citologia , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Lectinas Tipo C/metabolismo , Glicoproteínas de Membrana/metabolismo , Ativação Plaquetária , Animais , Plaquetas/efeitos dos fármacos , Cálcio/metabolismo , Adesão Celular , Epoprostenol/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Adesividade Plaquetária , Agregação Plaquetária , Venenos de Víboras/metabolismo
8.
Cell Death Dis ; 3: e429, 2012 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-23171849

RESUMO

Adaptation to endoplasmic reticulum (ER) stress relies on activation of the unfolded protein response (UPR) and induction of autophagy. Indeed, cells die if ER stress is not countered by the UPR. Here we show in U937 cells that the ER stressors tunicamycin and thapsigargin cause increased expression of c-Jun N-terminal kinase 2 (JNK2), which allows regulation of the UPR, whose silencing or pharmacological inhibition delays BiP (immunoglobulin heavy-chain binding protein) upregulation, and causes earlier and greater expression of CCAAT/enhancer-binding protein-homologous protein (CHOP). Furthermore, we show that pharmacological inhibition or silencing of JNK2 causes accumulation of both p62 and the acidic compartment, caspase 3 activation and apoptosis. Our results reveal that JNK2 prevents accumulation of the acidic compartment in U937 cells undergoing autophagic flux and, by this mechanism, it keeps stressed cells alive. Our findings highlight a potential role for JNK2 in tumor cell survival, senescence and neurodegenerative diseases, in which ER stress, autophagy and lysosome activity are known to interplay.


Assuntos
Estresse do Retículo Endoplasmático , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Neoplasias/enzimologia , Neoplasias/fisiopatologia , Apoptose , Caspase 3/genética , Caspase 3/metabolismo , Sobrevivência Celular , Humanos , Proteína Quinase 9 Ativada por Mitógeno/genética , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , Células U937
9.
Curr Cancer Drug Targets ; 8(5): 414-20, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18690847

RESUMO

Recent phase II randomised trials in colorectal cancer failed to demonstrate any advantage of celecoxib combined with standard chemotherapy; some authors even reported that the addition of celecoxib to irinotecan and oxaliplatin in colon cancer results in an inferior response rate. This observation leads to the hypothesis that there are pharmacokinetic interactions between celecoxib and chemotherapeutic drugs. The aim of the study was to investigate the induction by celecoxib of some multidrug resistance proteins, MRP1, MRP2, MRP4 and MRP5, involved in the transport of irinotecan and 5-FU. WiDr and COLO-205 cells were treated with celecoxib at a clinically relevant concentration. A viability assay was performed by treating cells with chemotherapy alone and chemotherapy plus celecoxib. The expression of MRP1, MRP2, MRP4 and MRP5 was analysed by RT-PCR and Western blot analysis. The sub cellular localization of MRP4 and MRP5 was investigated by cryoimmunoelectron microscopy. In both cell lines celecoxib induced MRP4 and MRP5 over-expression at RNA and protein levels. No induction of MRP1 and MRP2 was observed in treated cells compared to controls. Cryoimmunoelectron microscopy showed increased MRP4 and MRP5 immunolabeling in celecoxib treated cells both at cytoplasmic level and along the plasma membrane. Our findings suggest that the low response rate observed in clinical trials using celecoxib added to 5-fluorouracil and irinotecan may reflect celecoxib-mediated extrusion of chemotherapeutic drugs from cancer cells through the up regulation of ATP-binding cassette proteins. Our findings, together with the results of clinical trials, may suggest that the combined use of celecoxib and drugs that are substrate for MRP4/MRP5 should be avoided.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Inibidores de Ciclo-Oxigenase/uso terapêutico , Pirazóis/uso terapêutico , Sulfonamidas/uso terapêutico , Western Blotting , Celecoxib , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Citoplasma/metabolismo , Resistencia a Medicamentos Antineoplásicos , Humanos , Técnicas Imunoenzimáticas , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Frações Subcelulares , Células Tumorais Cultivadas , Regulação para Cima
12.
J Thromb Haemost ; 3(12): 2784-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16359516

RESUMO

BACKGROUND: Patients treated with aspirin may have a reduced sensitivity to its antiplatelet effect. The mechanism accounting for such a reduced sensitivity might involve an impaired interaction of aspirin with cyclooxygenase-1 (COX)-1. OBJECTIVE: We sought to investigate whether platelets from patients under chronic treatment with aspirin still produce TxA2 and whether there is any relationship between the eventual persistent TxA2 formation and platelet aggregation. Finally, whether platelet-derived TxA2 can be inhibited by in vitro addition of aspirin. METHODS: Collagen-induced platelet aggregation and thromboxane-A2 (TxA2) were measured in 196 patients treated with aspirin (100-330 mg day(-1)) because of previous vascular events or presence of risk factors of atherosclerosis. RESULTS: Collagen-induced TxA2 production of the entire cohort was 128.7 +/- 21.6 pg 10(-8) cells, and was significantly correlated with platelet aggregation (Spearman's correlation coefficient = 0.44; P < 0.0001). Patients in the highest quartile of TxA2 showed higher platelet response to collagen (P < 0.0001) when compared with those in the lowest quartile. In a subgroup of 96 patients, platelets were treated in vitro with a TxA2 receptor antagonist (13-azaprostanoic acid) or aspirin before stimulation with collagen. 13-APA acid significantly inhibited platelet aggregation. Aspirin reduced (-72.9%) TxA2 production in patients with TxA2 values above the median but it was ineffective in those with TxA2 values below the median. CONCLUSION: In some patients chronically treated with aspirin platelet production of TxA2 may persist and account for enhanced platelet aggregation. Incomplete inhibition of COX-1 seems to be implicated in persistent TxA2 production.


Assuntos
Aspirina/farmacologia , Plaquetas/metabolismo , Resistência a Medicamentos , Tromboxano A2/biossíntese , Idoso , Aspirina/administração & dosagem , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/tratamento farmacológico , Colágeno , Ciclo-Oxigenase 1/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Tromboxano A2/antagonistas & inibidores , Tromboxano A2/fisiologia
15.
Am J Physiol Heart Circ Physiol ; 284(1): H41-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12388290

RESUMO

Carnitine is a physiological cellular constituent that favors intracellular fatty acid transport, whose role on platelet function and O(2) free radicals has not been fully investigated. The aim of this study was to seek whether carnitine interferes with arachidonic acid metabolism and platelet function. Carnitine (10-50 microM) was able to dose dependently inhibit arachidonic acid incorporation into platelet phospholipids and agonist-induced arachidonic acid release. Incubation of platelets with carnitine dose dependently inhibited collagen-induced platelet aggregation, thromboxane A(2) formation, and Ca(2+) mobilization, without affecting phospholipase A(2) activation. Furthermore, carnitine inhibited platelet superoxide anion (O(2)(-)) formation elicited by arachidonic acid and collagen. To explore the underlying mechanism, arachidonic acid-stimulated platelets were incubated with NADPH. This study showed an enhanced platelet O(2)(-) formation, suggesting a role for NADPH oxidase in arachidonic acid-mediated platelet O(2)(-) production. Incubation of platelets with carnitine significantly reduced arachidonic acid-mediated NADPH oxidase activation. Moreover, the activation of protein kinase C was inhibited by 50 microM carnitine. This study shows that carnitine inhibits arachidonic acid accumulation into platelet phospholipids and in turn platelet function and arachidonic acid release elicited by platelet agonists.


Assuntos
Ácido Araquidônico/metabolismo , Plaquetas/fisiologia , Carnitina/farmacologia , Estresse Oxidativo/fisiologia , Plaquetas/metabolismo , Proteínas Sanguíneas/metabolismo , Cálcio/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Concentração Osmolar , Fosfolipídeos/metabolismo , Fosforilação , Agregação Plaquetária/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Tromboxano A2/biossíntese
17.
Environ Health Perspect ; 109(3): 225-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11333182

RESUMO

We studied the effect of nickel ions on platelet function because hypernickelemia has been found in patients with acute myocardial infarction. We previously demonstrated that nickel can activate an intracellular pathway leading to cytoskeleton reorganization consequent to tyrosine phosphorylation of p60(src) in human platelets independently of integrin alpha-IIb-beta(3). Moreover, in von Willebrand factor-stimulated platelets, the tyrosine phosphorylation of pp60(c-src) is closely associated with the activation of phosphatidylinositol 3-kinase (PIK), and two adhesion receptors, glycoprotein (Gp)Ib and GpIIb/IIIa(alpha-IIb-beta(3)), are involved. In our study, 1 and 5 mM nickel in the presence of fibrinogen induced platelet aggregation (independently of protein kinase C activation) and secretion. The pretreatment with a PIK inhibitor, wortmannin, strongly decreased nickel-induced platelet aggregation. Platelet treatment with mocarhagin, a cobra venom metalloproteinase that cleaves GpIba, significantly reduced aggregation induced by 5 mM without affecting the response to other agonists such as adenosine diphosphate (ADP). Moreover, nickel caused PIK translocation to the cytoskeleton. Taken together, these observations suggest a partial involvement of both integrins alpha-IIb-beta(3) and GpIb-V-IX complex in Ni(2+)-induced platelet activation.


Assuntos
Poluentes Ambientais/farmacologia , Níquel/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIb-IX de Plaquetas/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Humanos , Immunoblotting , Infarto do Miocárdio/etiologia , Exposição Ocupacional/efeitos adversos
18.
Thromb Haemost ; 85(2): 320-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11246555

RESUMO

Cyclic nucleotides, such as cAMP, are known to inhibit the multistep cascade that results in platelet aggregation. In the present study we provide evidence that it is possible to bypass cAMP inhibitory effect on fibrinogen binding site exposure induced by the thromboxane A2 synthetic analogue U46619, the snake venom toxin convulxin, or by the direct PKC activator OAG, by concomitantly activating a G1-coupled receptor by means of epinephrine or by inducing cytosolic calcium influx by means of ionomycin. In fact, in our study we demonstrate that, in iloprost-treated platelets, the inhibition of both platelet aggregation and fibrinogen binding was overcome by adding epinephrine or ionomycin. To further confirm this, we used the cAMP analogue dibutyryl cAMP and we obtained platelet aggregation in response to U46619, convulxin or OAG plus epinephrine. Moreover, a complete inhibition of platelet aggregation in the presence of high concentrations of cAMP was observed only in the case of U46619, while a small percentage of aggregation persisted when convulxin or OAG were used, due to the small amount of ADP that both convulxin and OAG are able to release. Since PKC inhibition didn't allow platelet aggregation to occur in response to the concomitant activation of U46619 or convulxin, plus epinephrine or ionomycin, we can conclude that cAMP-induced inhibition of aggregation can be counteracted by the simultaneous activation of PKC in the presence of an activated G1-coupled receptor or of an induced calcium influx.


Assuntos
AMP Cíclico/metabolismo , Lectinas Tipo C , Ativação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Venenos de Crotalídeos/farmacologia , AMP Cíclico/farmacologia , Citosol/química , Diglicerídeos/farmacologia , Epinefrina/farmacologia , Fibrinogênio/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Humanos , Iloprosta/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia
20.
Am J Clin Nutr ; 72(5): 1150-5, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11063442

RESUMO

BACKGROUND: Epidemiologic studies have shown an inverse relation between moderate consumption of red wine and cardiovascular disease. Studies have shown that red wine and its component flavonoids inhibit in vivo platelet activation, but the underlying mechanism has not yet been identified. OBJECTIVE: Because we showed previously that collagen-induced platelet aggregation is associated with a burst of hydrogen peroxide, which in turn contributes to stimulating the phospholipase C pathway, the aim of this study was to investigate whether flavonoids synergize in inhibiting platelet function and interfere with platelet function by virtue of their antioxidant effect. DESIGN: We tested the effect of 2 flavonoids, quercetin and catechin, on collagen-induced platelet aggregation and hydrogen peroxide and on platelet adhesion to collagen. RESULTS: Catechin (50-100 micromol/L) and quercetin (10-20 micromol/L) inhibited collagen-induced platelet aggregation and platelet adhesion to collagen. The combination of 25 micromol catechin/L and 5 micromol quercetin/L, neither of which had any effect on platelet function when used alone, significantly inhibited collagen-induced platelet aggregation and platelet adhesion to collagen. Such a combination strongly inhibited collagen-induced hydrogen peroxide production, calcium mobilization, and 1,3,4-inositol triphosphate formation. CONCLUSIONS: These data indicate that flavonoids inhibit platelet function by blunting hydrogen peroxide production and, in turn, phospholipase C activation and suggest that the synergism among flavonoids could contribute to an understanding of the relation between the moderate consumption of red wine and the decreased risk of cardiovascular disease.


Assuntos
Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Catequina/farmacologia , Peróxido de Hidrogênio/sangue , Quercetina/farmacologia , Cálcio/sangue , Colágeno/farmacologia , Sinergismo Farmacológico , Ativação Enzimática , Citometria de Fluxo , Humanos , Fosfatos de Inositol/sangue , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Fosfolipases Tipo C/sangue
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