Os envenenamentos causados pelas serpentes do gênero Bothrops são os mais importantes do ponto de vista médico e econômico na América Central. Dentre estas, a serpente Bothrops asper é responsável por 90% dos envenenamentos ofídicos registrados no Panamá anualmente. Apesar da relevância médica e econômica, só a peçonha de populações de B. asper da Costa Rica e Guatemala tem sido estudadas em detalhes. Neste trabalho apresentamos a caracterização da peçonha da B. asper do Panamá e o isolamento, a caracterização funcional e estrutural de quatro fosfolipases A2 básicas denominadas MTX-I, MXT-II, MTX-III e MXT-IV e de uma fosfolipase A2acídica denominada Basp-I-PLA2. As fosfolipases A2 foram isoladas da peçonha em duas etapas usando cromatografia de troca iônica em CM-Sepharose (0,05 M NH4HCO3 pH 8,1), e cromatografia hidrofóbica em Fenil-Sepharose (0,05 M Tris-HCl pH 7,4) seguida de gradiente de concentração de 4 a 0 M NaCl no mesmo tampão a temperatura ambiente (25°C). A isoforma acídica demonstrou maior atividade catalítica que as isoformas básicas, quando atuou sobre fosfatidilcolina e fosfatidilglicerol. A focalização isoelétrica evidencia pIs de 8,1 a 8,3 para as MTXs e 4,6 para isoforma Basp-I-PLA2. A determinação da massa molecular por espectrometria de massa mostrou que MTX-1 14,156.5; MTX-2 14,249.5 e MTX-3 14,253.0 e Basp-I-PLA2 14,246.0 Da. As PLA2s (MTX-I, II, III e IV) induziram atividade miotóxica, reação inflamatória com migração de leucócitos ao músculo e ativação de macrófagos para exercer fagocitose e produção de superóxido. MTX-II exerceu um forte efeito citotóxico contra células tumorais JURKAT, C. albicans e E. coli. A fosfolipase A2 acídica, testada no plasma enriquecido com plaquetas, mostrou potente efeito inibitório na agregação plaquetária induzida pela ADP e colágeno. A análise de seqüência N- terminal demonstrou que as proteínas MTX-I, MTX-III e Basp-I-PLA2 pertencem à subclasse de fosfolipases A2 Asp49 cataliticamente ativas, enquanto que, MTX-II e MTX-IV pertencem à subclasse de fosfolipases A2 Lys49-homólogas cataliticamente inativas. Além disso, a sequência N-terminal das fosfolipases A2 básicas isoladas, demonstrou claramente que as miotoxinas isoladas neste trabalho são similares às miotoxinas previamente isoladas da peçonha da B. asper da Costa Rica. A Basp-I-PLA2 é uma nova fosfolipase A2 acídica isolada da peçonha de B. asper do Panamá e sua seqüência N-terminal revelou uma alta homologia com outras PLA2s acídicas Asp49 isoladas de peçonhas de serpentes. / Envenoming by Bothrops snakes is the most serious kind of envenoming from the medical and economical point of view in Central America. Bothrops asper snake is responsible for 90% of the snakebites registered in Panama every year. Despite its medical and economical relevance, only the venom of Costa Rica and Guatemala populations of this species has been studied to some detail, and there is very little information on intraspecies variability in venom composition and toxicity. In this study the crude venom of B. asper from Panama was characterized and its pharmacological and biochemistry activities were investigated with standard laboratory assays. Furthermore, we describe the isolation, functional and structural characterization of four basic phospholipases A2, named MTX-I, MTX-II, MTX-III, MTX-IV and a new acid phospholipase A2 named Basp-I-PLA2. The proteins were isolated from the crude venom by a combination of two chromatographic steps, using ion-exchange chromatography on CM-Sepharose (0.05 M NH4HCO3 pH 8.1 buffer), and hydrophobic chromatography on Phenyl-Sepharose (0.05 M Tris-HCl pH 7.4), followed by concentration gradient from 4 to 0 M NaCl at 25°C in the same buffer. Analyses of phospholipids hydrolyzed by these enzymes have shown that all phospholipases belong to type A2. The acidic isoform demostraded more catalytic activity than the basic PLA2s. This enzyme was more active on substrates as phosphotidylcholine and phosphatidylglycerol. The isoelectric focusing evidenced pIs beetwen 8.1 to 8.3 for the MTXs and 4.6 for the isoform Basp-I-PLA2. Its mol. Wt was estimated by Mass spectrometry to be MTX-1 14,156.5; MTX-2 14,249.5 and MTX-3 14,253.0 and Basp-I-PLA2 14,246.0 Da. The PLA2s (MTX-I, II, III and IV) induced myotoxic activity, inflammatory reaction mainly leukocyte migration to the muscle and activation of macrophages to exert phagocytic activity and production of superoxide. MTX-II, the most abundant one showed to be cytotoxic against JURKAT tumor cell line, C. albicans and E. coli. The acidic phospholipases A2 when tested in platelet rich plasma, showed a potent inhibitory effect on aggregation induced by ADP and collagen. The analysis of the sequence N-terminal demonstrated that the MTX-I, MTX-III and BASP-I-PLA2 belong to the subclass of Asp49 phospholipases A2 catalytically active, whereas, MTX-II and MTX-IV belong to proteins of the subclass of the enzymatically inactive Lys49 PLA2 s-like. In addition, a sequence of the region N-terminal of the PLA2s basic isolated, demonstrated clearly, that the isolated myotoxins in this work are similar of the previously isolated myotoxins of the snake venom Bothrops asper from Costa Rica. The Basp-I-PLA2 is a new acidic PLA2 and his sequence N-terminal revealed a high homology with other Asp49 acidic PLA2 s from snake venoms.

Orientador: Gilberto De Nucci / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T16:13:57Z (GMT). No. of bitstreams: 1 Maziero_AlineMendes_D.pdf: 2175096 bytes, checksum: b3e712ed8baf6a7f7d4ef12131b9e85a (MD5) Previous issue date: 2014 / Resumo: Os eosinófilos participam de processos inflamatórios e alérgicos. Estando relacionados com o sistema de imunidade inata do organismo, eles representam uma linha fundamental de defesa contra invasão microbiana e, quando ativados, produzem uma série de mediadores solúveis que atuam nas respostas inflamatórias e alérgicas. A relação entre a atividade dos eosinófilos e plaquetas foi observada nas últimas décadas por muitos cientistas. Estas observações incluem o aumento do número de eosinófilos associados a desordens plaquetárias, incluindo alterações na cascata de coagulação e agregação plaquetária. Com base nessas observações, a interação entre os eosinófilos e plaquetas foram analisadas na agregação plaquetária. Plaquetas humanas foram incubadas com a fração citosólica de eosinófilos, linhagem celular promielocítica humana HL-60 clone 15 e proteína catiônica do eosinófilo (ECP). A agregação em plasma rico em plaquetas (PRP) foi induzida por difosfato de adenosina, fator de ativação plaquetária, ácido araquidônico e colágeno, e as plaquetas lavadas (PL) foram ativadas por trombina. A agregação induzida por todos os agonistas foi inibida de maneira concentração de células dependente pela fração citosólica de eosinófilos. Esta inibição foi apenas parcialmente revertida pela prévia incubação dos eosinófilos com L-Nitro-Arginina-metil-éster (L-NAME). A prévia incubação com indometacina não impediu a inibição induzida pela fração citosólica. A separação da fração citosólica de eosinófilos por gel filtração em Sephadex G-75 mostrou que a atividade inibitória foi concentrada na fração de peso molecular mais baixo. As células HL -60 clone 15 diferenciadas em eosinófilos por 5 e 7 dias foram capazes de inibir a agregação plaquetária. A proteína de ECP inibiu a agregação plaquetária em PRP e PL. Esta inibição foi mais evidente em PL, e o ensaio de citotoxicidade com MTT demonstrou a viabilidade de plaquetas testadas, indicando que a inibição observada pela proteína ECP não ocorre simplesmente pela morte celular. A proteína EDN, clonada e expressa em sistema eucarioto, também apresentou efeito de inibição sobre a agregação plaquetária em PRP, enquanto que a proteína MBP não apresentou efeito de inibição da agregação plaquetária significativo. Os nossos resultados indicam que os eosinófilos desempenham um papel fundamental na inibição da agregação plaquetária / Abstract: Eosinophils participate in allergic and inflammatory processes, being related to innate immunity system of the body, they represent a fundamental line of defense against microbial invasion and when activated produce a number of soluble mediators that act in inflammatory and allergic responses. The relationship between the activity of eosinophils and platelets has been observed in recent decades by many scientists. These observations include increased numbers of eosinophils associated with platelet disorders, including changes in the coagulation cascade and platelet aggregation. Based on these observations, the interaction between eosinophils and platelets in platelet aggregation was analyze. Human platelets were incubated with eosinophil cytosolic fraction, promyelocytic human HL-60 clone 15 cell lineage, and eosinophil cationic protein (ECP). Platelet rich plasma (PRP) aggregation was induced by adenosine diphosphate, platelet activating factor, arachidonic acid, and collagen, and washed platelets (WP) were activated by thrombin. Aggregation induced by all agonists was dose dependently inhibited by eosinophil cytosolic fraction. This inhibition was only partially reversed by previous incubation of the eosinophils with L-Nitro-Arginine-Methyl-Ester (L-NAME). Previous incubation with indomethacin did not prevent the cytosolic fraction induced inhibition. The separation of eosinophil cytosolic fraction by gel filtration on Sephadex G-75 showed that the inhibitory activity was concentrated in the lower molecular weight fraction. HL-60 clone 15 cells differentiated into eosinophils for 5 and 7 day were able to inhibit platelet aggregation. The ECP protein inhibited the platelet aggregation on PRP and WP. This inhibition was more evident in WP, and the citotoxicity MTT assay proved the viability of tested platelets, showing that the observed inhibition by the ECP protein does not occur simply by cell death. The EDN protein, cloned and expressed in eukaryotic system, also showed inhibitory effect on platelet aggregation in PRP, whereas the protein MBP had no effect significative inhibiting platelet aggregation. Our results indicate that eosinophils play a fundamental role in platelet aggregation inhibition / Doutorado / Farmacologia / Doutora em Farmacologia

Les accidents vasculaires cérébraux (AVC) constituent la 3e cause de mortalité dans les pays industrialisés, et sont à 80% de type ischémique (AVCi). A l’heure actuelle, le seul traitement disponible est l’activateur tissulaire du plasminogène recombinant (rt-PA), dont l’utilisation est très limitée, en raison d’une fenêtre thérapeutique étroite et de l’augmentation du risque de transformations hémorragiques (TH). Après un AVCi, les cliniciens sont confrontés, entre autres, à 3 objectifs d’ordre vasculaire: (1) reperfuser les tissus ischémiés, (2) éviter les TH, ainsi que (3) les ré-occlusions précoces ou tardives. Les travaux du laboratoire ont précédemment établi qu’après une ischémie cérébrale (IC), l’hyperactivation de la poly(ADP-ribose)polymérase (PARP), une enzyme nucléaire, est (1) neurotoxique et (2) contribue aux TH spontanées ou induites par le rt-PA. Par ailleurs, des études suggèrent que les inhibiteurs de PARP pourraient également réduire les phénomènes de ré-occlusion, en inhibant l’activation/agrégation plaquettaires, et ceci via 2 mécanismes : (1) « PARP-indépendant », lié à une analogie structurale de certains inhibiteurs de PARP avec des agonistes plaquettaires, comme l’ADP, et (2) « PARP-dépendant », lié à leur effet anti-inflammatoire. Cependant, à l’heure actuelle, il n’existe aucune donnée dans l’IC. Dans ce contexte, ce travail a consisté à évaluer les effets de plusieurs inhibiteurs de PARP sur l’activation et l’agrégation plaquettaire. Il nous est notamment apparu nécessaire de rechercher si la réduction des TH par les inhibiteurs de PARP pourrait être liée, au moins en partie, à une activité pro-agrégante, qui compromettrait leur association avec le rt-PA. A l’inverse, une activité anti-agrégante, bien que favorisant les hémorragies, pourrait améliorer la reperfusion ou diminuer les risques de ré-occlusion. Dans la 1ère partie, nos résultats montrent in vitro que deux inhibiteurs de PARP (PJ34 et minocycline) sont anti-agrégants plaquettaires, et que cet effet serait « PARP-indépendant », puisque deux autres inhibiteurs de PARP, le 3-aminobenzamide et l’INO-1001, n’ont pas modifié l’agrégation. De plus, sur du sang humain, mais pas murin, le PJ34 exerce un effet anti-agrégant, qui pourrait être lié à un antagonisme du récepteur à l’ADP, P2Y12. La 2nde partie a été réalisé sur des modèles in vivo chez la souris. L’utilisation de 3 tests d’exploration des fonctions plaquettaires (temps de saignement, modèles de thromboembolie pulmonaire et de thrombose carotidienne par le FeCl3) a mis en évidence l’absence d’effet du PJ34 et de la minocycline sur les fonctions plaquettaires, et notamment, pas d’effet pro-agrégant pouvant expliquer la réduction des TH. Dans un modèle de thrombose de l’artère cérébrale moyenne par le FeCl3, le PJ34 n’entrave pas la thrombolyse par le rt-PA, mais au contraire, pourrait tendre à l’améliorer. Parallèlement, dans un modèle d’IC chez la souris, nos travaux ont mis en évidence une augmentation cérébrale de l’adhésion des plaquettes et de l’expression d’ICAM-1. La suite de cette étude sera d’étudier si les inhibiteurs de PARP, en protégeant la paroi vasculaire, pourraient réduire les phénomènes de ré-occlusion. L’ensemble de ce travail s’inscrit dans une thématique plus globale de notre laboratoire qui vise à identifier l’intérêt d’associer un inhibiteur de PARP au rt-PA pour une meilleure prise en charge de la thrombolyse post-AVCi. / Stroke is the 3rd leading cause of death in industrialized countries and 80% are ischemic. The recombinant tissue-plasminogen activator (rt-PA) is currently the only available treatment but its use remains very limited due to a narrow therapeutic window and an increased risk of hemorrhagic transformation (HT). After ischemic stroke, the key vascular objectives of clinicians are : (1) to reperfuse ischemic tissue, (2) to avoid both HT and (3) early or late reocclusions. Our laboratory previously established that after cerebral ischemia (CI), the overactivation of poly(ADP-ribose)polymerase (PARP), a nuclear enzyme, is (1) neurotoxic and (2) contributes to spontaneous or rt-PA-induced HT. Moreover, studies suggest that PARP inhibitors could also reduce the risk of reocclusion by inhibiting platelet activation/aggregation via two mechanisms : (1) one is "PARP-independent" and linked to a structural analogy of certain PARP inhibitors with platelet agonists such as ADP, and (2) the second one is "PARP-dependent" and due to their anti-inflammatory effect. However, so far, there is no data in CI.In this context, the aim of this work was to evaluate the effects of several PARP inhibitors on platelet activation and aggregation. In particular, it appeared necessary to examine whether the reduction of HT by PARP inhibitors could be related, at least in part, to a pro-aggregatory activity, which would then compromise their association with rt-PA. By contrast, an anti-aggregatory activity could improve reperfusion or reduce the risk of reocclusion, although it would also contribute to hemorrhage. In the 1st part, our results show that, in vitro, two PARP inhibitors (PJ34 and minocycline) are antiplatelet agents and that this effect is "PARP-independent" since two other PARP inhibitors, 3-aminobenzamide and INO-1001 did not alter the aggregation. Moreover, in human blood but not in murine one, PJ34 exerts an anti-aggregatory effect which may be related to the antagonism of the ADP receptor P2Y12. The 2nd part was performed on in vivo models in mice. The use of three tests of platelet function exploration (bleeding time and models of pulmonary thromboembolism and FeCl3-induced carotid thrombosis) showed no effect of minocycline and PJ34 on platelet function and in particular, no pro-aggregatory effect which may explain the reduction of HT. In a thrombosis model of the middle cerebral artery by FeCl3, PJ34 does not impede the thrombolysis induced by rt-PA, but even tends to improve it. Meanwhile, in a CI model in mice, our work shows an increase of platelet adhesion and ICAM-1 expression in the brain. The next step will be to investigate whether PARP inhibitors could reduce reocclusions by protecting the vascular wall. All this work is part of a broader topic of our laboratory aims to identify the interest of combining a PARP inhibitor with rt-PA for a better management of post-ischemic thrombolysis.

La numération plaquettaire est une analyse délicate et le résultat est souvent erroné notamment du fait d’une tendance à l’agrégation in vitro dans certaines espèces animales. Il a ainsi pu être démontré chez le Chat que ce phénomène peut être inhibé par l’association d’un anticoagulant avec des inhibiteurs plaquettaires : le CTAD (Citrate, Théophylline, Adénosine et Dipyridamole). Cette association permet ainsi l’obtention de numérations plaquettaires fiables sans affecter les autres populations sanguines, mais également d’effectuer des analyses d’hémostase et de biochimie. De nouveaux intervalles de référence ont dû être établis pour certaines variables hématologiques avec les analyseurs utilisés en laboratoire et dans les cliniques vétérinaires. Par ailleurs, si les effets antiagrégants du CTAD sont moins nets chez le Chien, il peut également servir d’anticoagulant « universel », permettant de réduire le nombre de prélèvements et d’améliorer ainsi le bien-être des animaux. / The platelet count is a delicate measurement, which may often be erroneous because of the tendency of platelets from some animal species to aggregate in vitro. This study demonstrated that this effect can be inhibited in cats using CTAD (Citrate, Theophylline, Adenosine and Dipyridamole) composed of an anticoagulant and platelet inhibitors. This association provides reliable platelet counts without affecting other blood populations and also allows hemostasis and biochemical analyses. New hematological reference intervals have been established for some variables with analyzers used in clinical pathology laboratories and veterinary clinics. Furthermore, if the antiplatelet clumping effects of CTAD are less marked in canine species, the CTAD can also serve as "universal" anticoagulant, reducing the number of blood samples and thus improving animal welfare.

Orientador: Sisi Marcondes Paschoal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T18:31:06Z (GMT). No. of bitstreams: 1 Bonfitto_PedroHenriqueLeite_M.pdf: 791921 bytes, checksum: 967c29bbcdf8e6df7bd3a2d919b84111 (MD5) Previous issue date: 2015 / Resumo: As plaquetas são importantes células na inflamação, entretanto, os trabalhos que estudam as citocinas na reatividade plaquetária são raros. O objetivo do presente trabalho foi estudar os efeitos do fator de necrose tumoral-alfa (TNF-?) em plaquetas. Ensaios de agregação foram realizados incubando-se plaquetas com crescentes concentrações de TNF-? (1 - 3000 pg/ml) por diferentes intervalos de tempo (5 - 60 min), na ausência ou presença do antagonista não seletivo dos receptores TNFR1 e TNFR2, o R7050. Também foi estudado o efeito do TNF-? na viabilidade plaquetária utilizando-se o MTT. O efeito do TNF-? na mobilização de Ca2+ em plaquetas foi investigado através de ensaios de fluorescência utilizando-se o fluo-3-AM; os ensaios de western blotting foram realizados para o estudo da ativação da enzima c-Src e do receptor de fibrinogênio. Finalmente, foram determinados os níveis intraplaquetários de AMPc e GMPc por ELISA. O TNF-? inibiu a agregação plaquetária induzida por ADP ou trombina de forma dependente da concentração da citocina e do tempo de incubação. O efeito inibitório máximo do TNF-? na agregação induzida por ADP (5 ?M) foi obtido com a concentração de 300 pg/ml por um tempo de incubação de 30 min (90 ± 7% de inibição), o qual foi significativamente prevenido pela pré-incubação das plaquetas com o R7050. A viabilidade plaquetária não foi modificada pela incubação por 60 min com o TNF-? (30 e 3000 pg/ml). A incubação de plaquetas com TNF-? (300 pg/ml, 30 min) reduziu em 53% o aumento da concentração de Ca2+ total causado pela adição de trombina (200 mU/ml). A queda da concentração de Ca2+ citosólica plaquetária causada pelo TNF-? foi em decorrência da diminuição em 1,8 e 3,4 vezes da mobilização interna do íon e do influxo do mesmo, respectivamente. O TNF-? reduziu em 60% os níveis de AMPc em plaquetas ativadas com ADP. Por outro lado, o TNF-? aumentou significativamente os níveis de GMPc em plaquetas ativadas por ADP (aumento de 51%). A pré-incubação de plaquetas com o inibidor da guanilil ciclase ODQ não reduziu o efeito inibitório do TNF-? na agregação induzida por ADP. Os ensaios de western blotting mostraram que o TNF-? reduziu significativamente a fosforilação do resíduo de Tyr416 da c-Src em plaquetas ativadas. Da mesma forma, o TNF-? reduziu em 37% a fosforilação do resíduo de Tyr773 da subunidade ?3 da integrina ?IIb?3 (receptor de fibrinogênio) em plaquetas ativadas por ADP. Portanto concluímos que o TNF-? inibe a agregação plaquetária via receptores TNFR1 e/ou TNFR2, sem reduzir a viabilidade das plaquetas. O efeito inibitório do TNF-? na agregação é acompanhado pela redução de Ca2+ citosólico e inibição de c-Src e do receptor de fibrinogênio em plaquetas, sendo estes independentes de AMPc ou GMPc / Abstract: Platelets have been described as important cells in inflammation; however, the effects of cytokines on platelet reactivity are rarely studied. The objective of the present work was to investigate the effects of the tumor necrosis factor-alpha (TNF-?) in platelets. Aggregation assays were carried out incubating platelets with increasing TNF-? concentrations (1 - 3000 pg/ml) for different intervals of times (5 - 60 min), in the absence or in presence of the non-selective antagonist of TNFR1 and TNFR2, R7050. Effect of TNF-? on platelet viability was determined using MTT. The effect of TNF-? on the Ca2+ mobilization in platelets was investigated through fluorescence assays using fluo-3AM and Western blotting assays were carried out to determine the activation of c-Src and the fibrinogen receptor. Finally, the cAMP and cGMP levels in platelets were determined by ELISA. TNF-? dose- and time-dependently inhibited ADP or thrombin-induced platelet aggregation. The inhibitory effect of TNF-? on ADP(5 ?M)-induced platelet aggregation was maximum in a concentration of 300 pg/ml incubated with platelets for 30 min (90 ± 7% of inhibition), which was significantly prevented by the incubation of platelets with R7050. Platelet viability was not modified by TNF-? (30 and 3000 pg/ml) incubated for 5 to 60 min. Incubation of platelets with TNF-? (300 pg/ml, 30 min) reduced the increased total Ca2+ concentration induced by thrombin (200 mU/ml) by 53%. Decreasing Ca2+ internal mobilization (1,8 fold) and decreasing in external Ca2+ influx (3,4 fold) led to a reduction of total cytosolic Ca2+ in TNF-? activated platelets. TNF-? reduced the cAMP levels in ADP-activated platelets by 60%. On the other hand, TNF-? significantly increased cGMP levels in ADP-activated platelets (51% increase). Pre-incubation of platelets with the guanylyl cyclase inhibitor ODQ did not modify the inhibitory effect of TNF-? on ADP-induced platelet aggregation. Western blotting analysis showed that TNF-? significantly reduced phosphorylation on Tyr416 of c-Src in activated platelets. Similarly, TNF-? reduced by 37% the Tyr773 phosphorylation of ?3 subunit of ?IIb?3 integrin (fibrinogen receptor) in ADP-activated platelets. Therefore, our results show that TNF-? inhibits platelet aggregation via TNFR1 and/or TNFR2 receptors, without affecting platelet viability. The inhibitory effect of TNF-? on aggregation is accompanied by a reduction in cytosolic Ca2+ and the inhibition of c-Src and fibrinogen receptor activation, which are cAMP and cGMP-independent effects / Mestrado / Farmacologia / Mestre em Farmacologia

INTRODUÇÃO: Racional: A alta atividade plaquetária residual (AAPR) em uso do AAS é considerada um fator de mau prognóstico em portadores de síndrome isquêmica miocárdica instável (SIMI). Adicionalmente, as taxas de prevalência de AAPR verificadas em diferentes estudos realizados na fase aguda das SIMI são consideradas elevadas em relação às verificadas em portadores de doença arterial coronariana estável. Todavia, não está bem demostrado se essa elevada prevalência de AAPR diagnosticada na fase aguda das SIMI representa um fenômeno transitório, desaparecendo na fase tardia, ou se é um estado permanente, independente da fase aguda. MÉTODOS: O objetivo primário do presente estudo foi o de comparar, em pacientes com SIMI sem supradesnível do segmento ST, a resposta antiplaquetária ao AAS nas fases aguda e tardia na mesma população. Foram incluídos 70 pacientes com SIMI sem supradesnível de ST (77% com angina instável e 22% com IAM sem supra de ST), com idade média de 64,97 anos, sendo 54% do sexo feminino, todos em uso de AAS na dose de 100 a 200mg por pelo menos sete dias anteriores à inclusão. Os pacientes foram submetidos a cinco testes de agregação plaquetária na fase aguda, e os mesmos testes foram repetidos na fase tardia, três meses depois: VerifyNowAspirin®, agregometria de sangue total (AST) com ácido aracdônico (AA) e colágeno, tromboxane B2 sérico, PFA-100. RESULTADOS: De acordo com os testes COX-1 específicos (VFN e AST com AA), a AAPR em uso do AAS foi mais prevalente na fase aguda das SIMI do que na fase tardia (VFN: 32,1% versus 16%, p=0,049; e AST com AA: 31,4% versus 12,8%, p=0,015). Os testes não específicos (AST com colágeno, PFA) e o teste bioquímico não conseguiram demonstrar diferenças entre as fases. A correlação entre os cinco testes realizados foi considerada fraca ou moderada. CONCLUSÃO: A alta prevalência de AAPR, apesar do uso da AAS durante as SIMI, reflete mais provavelmente um estado de hiper-reatividade plaquetária transitória, que se reverte na fase crônica e estável da DAC, de acordo com os testes COX-1 específicos. A correlação entre os testes plaquetários foi apenas moderada nos dois cenários / BACKGROUND: The high residual platelet activity (HRPA) in response to acetylsalicilic acid (ASA) is considered a poor prognostic factor in patients with acute coronary syndromes (ACS). Additionally, the HRPA prevalence rates reported by different studies in ACS patients are considered high compared to those reported in patients with stable coronary artery disease. However, it is not well demonstrated whether this high HRPA prevalence diagnosed during the acute phase represents a transient phenomenon, disappearing in the late phase, or if it is a permanent state, independent of the acute phase. The aim of this study was to compare platelet aggregation in response to ASA during the ACS acute phase with the platelet aggregation in chronic stable phase. METHODS: Inclusion of patients with non ST ACS who were on aspirin at a dose of 100mg to 200mg per day for at least seven days prior to inclusion. We conducted five tests of platelet aggregation in the first 48 hours and repeated them three months later: VerifyNow Aspirin® (VFN), Whole Blood aggregometry (WBA) with arachidonic acid (AA) and collagen, thromboxane B2, PFA-100®. We analyzed 70 patients (77% with unstable angina and 22% with non ST AMI), mean age 64.97 years, 54% female. According to the COX-1 specific tests, the HRPA was more frequent in the acute phase than in the chronic phase (VerifyNowAspirin®: 31.4% versus 12.8%, p=0.015; and WBA with AA: 32.1% versus 16%, p=0.049; respectively). The non specific tests (AST with collagen and PFA) and the biochemical test sTXB2 failed to show differences between the phases. The correlation between the five tests was considered weak or moderate. CONCLUSION: The high prevalence of RPA despite the use of aspirin during the acute phase of the SCA most likely reflects a state of transient platelet hyperreactivity, which is reversed in the chronic phase. The correlation between platelet tests was only moderate in both scenarios

No description available.

The purpose of this study was to evaluate the effectiveness of aspirin (ASA) and porcine endothelial cell seeding in improving the patency rate of vena cava grafts. Thirty-nine dogs underwent infrarenal vena cava replacement by 10 cm lengths of 8 mm I.D. ringed polytetrafluoroethylene grafts. Thirty-one grafts were seeded with 1-1.5 x 10(6) porcine aortic endothelial cells while eight were not (GIII). Of the seeded group, 16 animals received no ASA (GI), while 15 others (GII) were given ASA (325 mg) daily starting two days preoperatively and continuing until sacrifice. Venograms were performed on the fourth postoperative day. Grafts were harvested 32 days after insertion and evaluated for patency rate and endothelialized surfaces. The 32-day patency rate was significantly higher for GII than for GI and III animals (67% vs. 13 and 25% respectively). Endothelialized surface was higher in GII than Gi and III (67% vs. 16% and 18% respectively). We conclude that endothelial cell seeding alone does not prevent graft closure and that a combination of ASA and cell seeding significantly increases the patency rate of vena cava grafts.

<p>UVOD: Procesi koji obuhvataju endotelnu disfunkciju, oksidativni stres, hroničnu inflamaciju, hiperaktivnost i aktivaciju trombocita te naru&scaron;avanje ravnoteže procesa koagulacije i fibrinolize od najranijih faza razvoja dijabetes melitusa tip 2 (T2DM) promovi&scaron;u aterogenezu i nastanak aterotromboznih komplikacija. Kompleksan terapijski pristup u T2DM ima za cilj ne samo uspostavljanje glikoregulacije, korekciju brojnih metaboličkih poremećaja i modifikaciju pridruženih faktora rizika za nastanak ateroskleroze već i primenu antitrombocitne terapije u cilju primarne ili sekundarne prevencije aterotromboznih komplikacija. Uprkos primenjenoj antiagregacionoj terapiji, deo bolesnika doživi rekurentne aterotrombozne atake. Bolesnici sa T2DM se izdvajaju kao grupa sa posebnim rizikom za recidivantne aterotromboze &scaron;to može biti uslovljeno rezistencijom na primenjenu antitrombocitnu terapiju. Praćenje efekata antitrombocitne terapije i blagovremeno identifikovanje rezistentnih bolesnika ima za cilj optimizaciju primenjene antitrombocitne terapije &scaron;to može biti od izuzetnog kliničkog značaja u smislu sprečavanja progresije aterotromboznog procesa. CILJ: Proceniti i uporediti nivoe biomarkera, pokazatelja endotelne aktivacije, aktivacije i agregabilnosti trombocita u bolesnika sa bole&scaron;ću arterijskih krvnih sudova u tipu 2 dijabetes melitusa u odnosu na njihove vrednosti u zdravoj populaciji. Uporediti efikasnost primenjene antitrombocitne terapije tienopiridinima u bolesnika sa tipom 2 dijabetes melitusa i bole&scaron;ću arterijskih krvnih sudova u odnosu na efikasnost ove terapije u nedijabetičnoj populaciji bolesnika sa bole&scaron;ću arterijskih krvnih sudova. MATERIJAL I METODE: U ispitivanje je uključeno 100 ispitanika oba pola, starosti od 33 do 70 godina života, kod kojih je prethodno utvrđeno postojanje neke od kliničkih manifestacija bolesti arterijskih krvnih sudova (IBS, CVB, PAB) koji kao antitrombocitnu terapiju uzimaju tienopiridinski preparat, klopidogrel. Od toga, 50 uključenih ispitanika imalo je dijagnozu dijabetes melitus tipa 2, a 50 su bili bolesnici bez dijabetesa. Kontrolnu grupu je činilo 30 klinički i biohemijski zdravih ispitanika, nepu&scaron;ača koji su prema polnoj i dobnoj strukturi odgovarali ispitivanim grupama bolesnika. Svim ispitanicima su urađena antropometrijska merenja, laboratorijska analiza uzoraka krvi na automatizovanim analizatorima sa određivanjem parametara metabolizma glukoze, lipida, parametera inflamacije, KKS, parmetara koagulacije i trombocitnih pokazatelja. Određivanje serumske koncentracije sE&ndash;selektina i sP-selektina je vr&scaron;eno ELISA tehnikom (R&amp;D Systems, Inc. Minneapolis, USA). Plazmatska koncentracija vWFAg-a određivana je imunoturbidimetrijskom metodom na koagulacionom analizatoru Siemens Healthcare Diagnostics, Nemačka. Agregabilnost trombocita je određivana impedantnom agregometrijom (Multiple Electrode Aggregometry - MEA) na Multiplate analizatoru, Dynabyte, Minhen, Nemačka. Bazalna agregabilnost trombocita procenjivana je TRAP testom, rezidualna agregabilnost trombocita pod terapijom klopidogrela ADP testom, rezidualna agregabilnost trombocita pod terapijom aspirina, ASPI testom. Individualni odgovor na primenjenu antiagregacionu terapiju je procenjivan i na osnovu procenta sniženja bazalne agregabilnosti trombocita (%SAT) nakon primenjene antiagregacione terapije &scaron;to je izračunato sledećim formulama: procena antiagregacionog efekta klopidogrela:%SATadp =100 x (1-ADP/TRAP) i procena antiagregacionog efekta aspirina:%SATaspi =100 x (1-ASPI/TRAP). REZULTATI: Nivo sE-slektina je bio signifikantno vi&scaron;i u bolesnika sa T2DM u odnosu na bolesnike bez dijabetesa (45,1&plusmn;18,1vs.31,8&plusmn;10,5ng/ml; p&lt;0,001) i kontrolnu grupu zdravih ispitanika (45,1&plusmn;18,1vs.27,2&plusmn;11,2ng/ml; p&lt;0,001). Plazmatski nivo vWF Ag, bio je statistički značajno vi&scaron;i u bolesnika sa T2DM u odnosu na grupu ispitanika bez dijabetesa (172&plusmn;75,2vs. 146&plusmn;40,6%; p=0,045), kao i u odnosu na kontrolnu grupu zdravih (172&plusmn;75,2vs.130&plusmn;33,8%; p=0,007). Nivo sPselektina bio je statistički značajno vi&scaron;i kod bolesnika s T2DM u odnosu na ispitanike u grupi dijabetesa (95,2&plusmn;31,8vs.84,0&plusmn;21,8 ng/ml; p=0,042) i kontrolnoj grupi (95,2&plusmn;31,8vs.76,7&plusmn;16,2ng/ml; p=0,004). Uočeno je da je %rP statistički bio značajno vi&scaron;i u grupi dijabetičara u odnosu na grupu ispitanika bez dijabetesa (3,47&plusmn;1,30vs.2,30&plusmn;1,30%; p&lt;0,001) i kontrolnu grupu zdravih (3,47&plusmn;1,30vs.2,29&plusmn;1,23%; p&lt;0,001). Bolesnici sa T2DM imali su statistički značajno vi&scaron;e vrednosti ADP testa (70,3&plusmn;22,0vs.56,9&plusmn;19,7U; p=0,002) u odnosu na bolesnike bez dijabetesa, a uočen je i značajno niži stepen procenta sniženja bazalne agregabilnosti, %SATadp, u dijabetičara u odnosu na ispitanike bez dijabetesa (31,6&plusmn;12,4vs. 48,6&plusmn;12,6 %; p&lt;0,001). U grupi ispitanika sa T2DM vrednost TRAP testa statistički značajno pozitivno koreli&scaron;e sa brojem neutrofila (r=0,349;p= 0,013) i NLR-om (r=0,472;p=0,001), a multivarijantnom linearnom regresionom analizom dokazana je nezavisna povezanost TRAP testa i fibrinogena (B=9,61;p=0,009). Takođe, u istoj ispitivanoj grupi postoji pozitivna povezanost ADP testa sa HOMAIR (r=0,319;p=0,024), NLR-om (r=0,515;p&lt;0,001), hsCRP-om (r=0,356;p=0,011), kao i sa %rP (r=0,302;p=0,049). Multivarijantnom linearnom regresionom analizom dokazana je nezavisna povezanost ADP testa i ITM (B=1,43;p=0,043). %SATadp u bolesnika sa T2DM negativno je korelisao sa ITM (r= -0,381;p=0,006), OS (r= - 0,387;p=0,006), HOMA-IR (r= -0,349;p=0,013), hsCRP-om (r= -0,288; p=0,043), %rP (r= -0,302;p=0,049), sE-selektinom (r= -0,369; p=0,008) i sP-selektinom (r= - 0,374;p=0,007). U grupi dijabetičara, postoji pozitivna povezanost %rP sa ITM (r=0,365;p= 0,016), OS (r=0,435;p=0,004), HOMA-IR (r=0,409;p=0,006), hsCRP (r=0,374;p=0,014), sP-selektinom (r=0,341;p=0,025) i vWFAg-om (r=0,348;p=0,022). Takođe, sE-selektin pozitivno koreli&scaron;e sa ITM (r=0,380;p =0,006), OS (r=0,380; p=0,007), HOMA-IR (r=0,339;p=0,016), hsCRP-om (r=0,351;p=0,013), a sP-selektin sa ITM (r=0,312;p=0,027), OS (r=0,395;p=0,005), HOMA-IR (r=0,286;p=0,044), hsCRP-om (r=0,369; p=0,008) i nivoom sE &ndash; selektina (r=0,560;p &lt;0,001). Evaluirajući odgovor na terapiju klopidogrelom u podgrupama bolesnika sa dijabetesom, napravljenim prema kvartilnoj distribuciji nivoa ADP-a, tj. stepenu rezidualne agregabilnosti trombocita u toku terapije klopidogrelom, uočeno je da ukupna bazalna agregabilnost trombocita procenjena TRAP testom statistički značajno raste od prvog do četvrtog kvartila (76,50 &plusmn;19,91 vs. 94,54&plusmn;16,67 vs. 112,00&plusmn;10,22 vs. 128,92&plusmn;15,69U;p&lt;0,001), dok se %SATadp od prvog do četvrtog kvartila značajno smanjivao (40,44&plusmn;13,33 vs. 31,20&plusmn;11,82 vs. 33,16&plusmn;7,03 vs. 21,53&plusmn;10,16%). ZAKLJUČAK: Koncentracije cirkuli&scaron;ućih biomarkera endotelne aktivacije, sE &ndash; selektina i vWF Ag-a, solubilnog biomarkera trombocitne aktivacije, sP &ndash; selektina, kao i procenat retikulisanih trombocita, %rP, markera trombocitnog prometa, značajno su povi&scaron;ene kod bolesnika sa bole&scaron;ću arterijskih krvnih sudova u tipu 2 dijabetes melitusa u odnosu na njihove koncentracije kod zdravih ispitanika i bolesnika bez dijabetesa. Bolesnici sa T2DM imali su znatno vi&scaron;i stepen rezistencije na antitrombocitnu terapiju klopidogrelom u odnosu na bolesnike bez dijabetesa, procenjene stepenom rezidualne agregabilnosti trombocita, ADP test, kao i procentom sniženja ukupne bazalne agregabilnosti trombocita, %SATadp, metodom impedantne agregometrije, a &scaron;to je uslovilo i trend učestalijeg ponavljanja ishemijskih ataka u odnosu na bolesnike bez dijabetesa. Međusobna povezanost ispitivanih biomarkera endotelne i trombocitne aktivacije (sE &ndash; selektina, vWF Aga, sP &ndash; selektina), kao i markera prometa trombocita (%rP) sa metaboličko inflamatornim parametrima i sa indikatorima odgovora na antiagregacionu terapiju, može ukazivati na to da nepovoljan metabolički milje dijabetičara može biti jedan od doprinosnih faktora lo&scaron;em odgovoru na antitrombocitnu terapiju klopidogrelom.</p> / <p>INTRODUCTION: Processes involving endothelial dysfunction, oxidative stress, chronic inflammation, platelet activation and the imbalance between coagulation and fibrinolysis promote atherogenesis and atherothrombotic complications at early stage of diabetes mellitus type 2 (T2DM). The complex therapeutic approach in T2DM aims not only to reestablish glycemic control and to correct a number of metabolic disorders, but also to achieve primary or secondary prevention of atherothrombotic complications. Despite the applied antiplatelet therapy, some patients experience recurrent atherothrombotic attacks. Patients with T2DM are the group at particular risk for recurrent atherothrombosis, which can be caused by antiplatelet therapy resistance. Monitoring the effectiveness of antiplatelet therapy and identification of resistant patients aims to optimize the applied antiplatelet therapy, which can be of great clinical significance in terms of preventing progression of atherotrombotic processes. AIM: Evaluate and compare the levels of biomarkers, indicators of endothelial activation, platelet activation and aggregability in patients with arterial vascular disease in type 2 diabetes mellitus compared to their values in a healthy population. Compare the effectiveness of applied antiplatelet therapy with thienopyridines in patients with type 2 diabetes mellitus and arterial vascular disease compared to the efficacy of this therapy in nondiabetic population of patients with arterial vascular disease. MATERIAL AND METHODS: The study included 100 patients, 33 to 70 years of age, with previously established existence of some of the clinical manifestations of arterial vascular disease (CAD, CVD, PAD), taking thienopyridine antiplatelet therapy with clopidogrel. 50 patients was previously diagnosed with diabetes mellitus type 2 and 50 were nondiabetic patients. Control group included 30 age and sex matched healthy participants, non-smokers. All subjects underwent anthropometric measurements and laboratory analysis of blood samples on automated analyzers with determining the parameters of glucose metabolism, lipids, inflammation parameters, complete blood count, coagulation and platelet parameters. Serum concentrations of sEselectin and sP-selectin were determined by ELISA (R&amp;D Systems, Inc., Minneapolis, USA). vWFAg was determined by immunoturbidimetry on coagulometer Siemens Healthcare Diagnostics, Germany. Platelet aggregability was determined by impedance aggregometry (Multiple Electrode Aggregometry - MEA) on Multiplate analyzer, Dynabyte, Munich, Germany. Basal platelet aggregability was estimated by TRAP test, residual platelet aggregability during clopidogrel treatment was estimated by ADP test and during aspirin treatement by ASPI test. Individual response to antiplatelet therapy was estimated by the percentage of decrease in basal platelet aggregability (%DPA) obtained after antiplatelet therapy, calculated bypresented formulas: %DPAadp =100 x (1-ADP/TRAP)and %DPAaspi =100 x (1- ASPI/TRAP). RESULTS: Concentration of sE-selectin was significantly higher in patients with T2DM in order to non-diabetic patients (45,1&plusmn;18,1vs.31,8&plusmn;10,5ng/ml;p&lt;0,001) and healthy control group (45,1&plusmn;18,1vs.27,2&plusmn;11,2ng/ml; p&lt;0,001). vWF Ag was significantly higher in diabetic patients than in non-diabetics (172&plusmn;75,2vs. 146&plusmn;40,6%; p=0,045) and healthy controls (172&plusmn;75,2vs.130&plusmn;33,8%; p=0,007). sP-selectin was also significantly higher in patients with T2DM than in non-diabetics (95,2&plusmn;31,8vs.84,0&plusmn;21,8 ng/ml; p=0,042) and healthy controls (95,2&plusmn;31,8vs.76,7&plusmn;16,2ng/ml; p=0,004). %rP was significantly higher in group of patients with T2DM than in nondiabetic patients (3,47&plusmn;1,30vs.2,30&plusmn;1,30%; p&lt;0,001) and healthy control group (3,47&plusmn;1,30vs.2,29&plusmn;1,23%; p&lt;0,001). T2DM patients had statistically higher values of ADP test (70,3&plusmn;22,0vs.56,9&plusmn;19,7U; p=0,002) compared to patients without diabetes, and significantly lower %DPAadp (31,6&plusmn;12,4vs. 48,6&plusmn;12,6 %; p&lt;0,001). In T2DM group of patients, level of TRAP test correlated positively with number of white blood cells (r=0,349;p= 0,013) and NLR (r=0,472;p=0,001), and multivariant linear regression analisys showed significant independent association of TRAP test with fibrinogen (B=9,61;p=0,009). Statistically significant positive correlation of ADP test with HOMA-IR (r=0,319;p=0,024), NLR (r=0,515;p&lt;0,001), hsCRP (r=0,356;p=0,011) and %rP (r=0,302;p=0,049) was observed in patients with T2DM. Multivariant linear regression analisys showed significant independent association of ADP test with BMI (B=1,43;p=0,043). %DPAadp negatively correlated with BMI (r=-0,381;p=0,006), WC (r= - 0,387;p=0,006), HOMA-IR (r= -0,349;p=0,013), hsCRP (r= -0,288; p=0,043), %rP (r= -0,302;p=0,049), sE-selectin (r= -0,369; p=0,008) and sP-selectin (r= -0,374;p=0,007) in diabetic patients. Significant positive correlation of %rP with BMI (r=0,365;p= 0,016), WC (r=0,435;p=0,004), HOMA-IR (r=0,409;p=0,006), hsCRP (r=0,374;p=0,014), sP-selectin (r=0,341;p=0,025) and vWFAg (r=0,348;p=0,022) was found in diabetics. Also, sE-selectin positively correlated with BMI (r=0,380;p =0,006), WC (r=0,380; p=0,007), HOMA-IR (r=0,339;p=0,016), hsCRP(r=0,351;p=0,013), and sPselectin correlated positively with BMI (r=0,312;p=0,027), WC (r=0,395;p=0,005), HOMA-IR (r=0,286;p=0,044), hsCRP (r=0,369; p=0,008) and sE &ndash; selectin (r=0,560;p &lt;0,001). Evaluating the response to clopidogrel therapy in subgrpoups of diabetic patients accoarding the quartile distribution of ADP test (clopidogrel on-treatment platelet reactivity), it is found that total basal aggregability estimated by TRAP test significantly increased from the first to the fourth quartile (76,50 &plusmn;19,91 vs. 94,54&plusmn;16,67 vs. 112,00&plusmn;10,22 vs. 128,92&plusmn;15,69U;p&lt;0,001) while %DPAadp decreased (40,44&plusmn;13,33 vs. 31,20&plusmn;11,82 vs. 33,16&plusmn;7,03 vs. 21,53&plusmn;10,16%). CONCLUSION: Concentration of circulating biomarkers of endothelial activation, sE-selectin and vWF Ag, soluble marker of platelet activation, sP &ndash; selectin, as well as percentage of reticulated platelets, %rP, marker of platelet turnover, were significantly higher in patients with arterial vascular disease in T2DM compared to healthy controls and non-diabetics. Patients with T2DM had significantly higher degree of resistance to antiplatelet therapy with clopidogrel compared to non diabetics, estimated by ADP test, as well as with %DPAadp, what caused more frequent recurrent ischemic attacks compared to nondiabetic patients. Correlation of biomarkers of endothelial and platelet activation (sE &ndash; selectin, vWF Ag, sP &ndash; selectin) and markers of platelet turnover (%rP) with metabolic profile indicators and poor antiplatelet therapy response suggest that altered metabolic profile can be one of contributing factors of poor antiplatelet response in diabetic patients.</p>

Distúrbios de hemostasia são uma das principais manifestações clínicas observadas nos acidentes por serpentes do gênero Bothrops. Tendo em vista a importância da ativação de fatores da cascata de coagulação no desenvolvimento da patologia no envenenamento, o presente trabalho descreve o isolamento e a caracterização bioquímica e funcional de uma metaloprotease capaz de induzir a ativação de fatores de coagulação, a partir da peçonha de Bothrops moojeni. A metaloprotease foi isolada por três etapas cromatográficas utilizando colunas de exclusão molecular (Sephacryl S-200), interação hidrofóbica (Phenyl Sepharose) e troca aniônica (ES 502N). A protease isolada, denominada moojenactivase, é uma glicoproteína com massa molecular de aproximadamente 89 kDa e ponto isoelétrico de 4,92, sendo composta por três cadeias com massas de 66; 17 e 14 kDa, ligadas por pontes dissulfeto. A determinação da sequência de aminoácidos por espectrometria de massas evidenciou grande identidade sequencial com outras metaloproteases, indicando a presença dos domínios metaloprotease, desintegrina-like e lectinas-like e classificando-a como uma protease da classe PIIId. Funcionalmente, a moojenactivase foi capaz de induzir a cogulação de plasma humano pela ativação dos fatores II (protrombina) e X da cascata de coagulação, gerando -trombina e fator X ativado, respectivamente. A protease apresentou atividade fibrinogenolítica, especialmente sobre a cadeia da molécula de fibrinogênio, porém não foi capaz de induzir a formação do coágulo de fibrina pela ativação deste. A moojenactivase foi parcialmente inibida quando incubada em condições de pH entre 3,5 e 5,0 e em pH 9,0, além de temperaturas acima de 60ºC, bem como na presença de ions Cu2+, além dos inibidores EDTA, SDS, DTT e soro anti-ofídico crotalico/botrópico. A protease induziu agregação plaquetária e não apresentou atividades fibrinolítica e hemorrágica. Células mononucleares de sangue periférico (PBMC) tratadas com a protease foram capazes de produzir TNF- assim como expressar fator tecidual (Fator III da coagulação) na forma ativa, fazendo com que essas células apresentassem caráter procoagulante. Com o objetivo avaliar os efeitos nos parâmetros hematológicos in vivo, a moojenactivase foi administrada em ratos (3g/Kg) onde foi observado que a protease foi capaz de prolongar o tempo de sangramento dos animais e induzir a diminuição do número de plaquetas sanguíneas, caracterizando um quadro de trombocitopenia. Ainda, o plasma dos animais administrados com a moojenactivase apresentaram valores elevados do tempo de protrombina e tempo de tromboplastina parcialmente ativada, assim como redução na concentração de fibrinogênio. Na análise dos parâmetros da série branca, foi observado aumento leucocitário na circulação, com predominância de neutrófilos até 3h após a administração, indicando a instalação de um quadro inflamatório. Com relação à análise da série vermelha, a moojenactivase não foi capaz de alterar nenhum dos parâmetros estudados. Os resultados obtidos no presente trabalho mostram, pela primeira vez, o isolamento de uma metaloprotease da classe P-IIId da peçonha de Bothrops moojeni capaz de atuar sobre diferentes ii eventos do processo hemostático, sendo essa ação prócoagulante responsável pelo quadro de incoagulabilidade sanguínea em animais. Os dados gerados podem auxiliar no entendimento dos distúrbios de coagulação em pacientes envolvidos em acidentes por serpentes da espécie Bothrops moojeni, levando ao melhor direcionamento na terapia anti-ofídica. Ainda, a função da moojenactivase sobre componentes biológicos credencia a molécula para uma possível aplicação biotecnológica em processos que envolvem o sistema hemostático. / Haemostasis disorders are a major clinical manifestation induced by Bothrops snake envenomations. Considering the relevance of the activation of coagulation factors during the envenomation pathophysiology, the present work describes, for the first time, the isolation and functional and biochemical characterization of a coagulation factor activator metalloprotease from Bothrops moojeni snake venom. The protease was purified by three chromatographic procedures using size exclusion (Sephacryl S-200), hydrophobic interaction (Phenyl Sepharose) and anion exchange (ES 502N) chromatographies. The isolated protease, named moojenactivase, is a glycoprotein with molecular mass of approximately 89 kDa by SDS-PAGE, and composed of 66 kDa, 17 kDa and 14 kDa disulfide linked chains, with pI of 4,92. The amino acid sequence determination of tryptic peptides from moojenactivase by mass spectrometry presented fragments with high identity to snake venom metalloproteases, confirming the presence of the metalloprotease, disintegrin-like and lectin-like domains, which allowed its classification as a PIIId class snake venom metalloprotease. Regarding its functional properties, the protease was capable to induce human plasma coagulation by inducing activation of coagulation factors II and X, forming-thrombin and factor X activated, respectively. Also, moojenactivase presented fibrinogenolitic activity, by cleaving preferentially -chain of fibrinogen, however was not capable to induce the formation of fibrin clot from fibrinogen. The enzyme stability was assessed and showed that moojenactivase presented a reduced functional activity when preincubated in pH values ranging from 3,5 to 5,0 and at pH 9,0, and in temperature conditions over 60ºC. Cu2+ ions and inhibitors such as EDTA, SDS, DTT and crotalic/bothropic antiophidian serum reduced the protease activity. Moojenactivase induced platelet aggregation, but no fibrinolytic and haemorrhage activities. In order to evaluate the stimulation of peripheral blood mononuclear cells (PBMC), cells were treated with the protease and we observed the release of proinflammatory cytokine TNF- and expression of active Tissue Factor (coagulant factor III), inducing a procoagulant state on PBMC. In order to evaluate in vivo haematological effects, the protease (3 g/Kg) was administered in rat (i.v.) and was observed that moojenactivase induced a prolonged bleeding time and reduced platelet counting (indicating a thrombocytopenia state). Moreover, the evaluation of the hemostasis parameters was assessed by the the prothrombin time and activated partial thromboplastin time assays and showed a prolonged clot time on both tests, and also a decrease in fibrinogen plasma levels. The leukogram analysis showed an increase in the circulating leukocyte number up to 3 hours after moojenactivase administration, composed predominantly of neutrophils. However, parameters envolving red cells shows that the protease do not affect. The results obtained in the present work show, for the first time, the isolation of a PIIId class metalloprotease from Bothrops moojeni snake venom involved on the activation of several hemostatic events, inducing a pro coagulant activity and leading to blood unclottable state in experimental animals. These data can assit in understanding coagulation disturbs in iv patients involved in Bothrops moojeni envenomation and leading to a better anti ophidic therapy guidance. Moreover, moojenactivase functional activities accredits this protease as a possible molecular instrument applied on biotechnological prospect related to the hemostasis.