Medicinal plants have long been used in folkloric medicine in various parts of the world. Presence of phenolic compounds has been attributed to their medicinal properties. Despite various medicinal uses, scientific claims of anti-hypertensive activities are still deficient. Therefore, hydroethanolic (70% ethanol) extracts of the leaf and root parts of T. officinale (TOL and TOR respectively) were investigated for anti-hypertensive antioxidant, diuretic activities, and effects on lipid profile in L-Name-induced hypertensive Wistar rats. Phytochemical screening of TOL and TOR was assessed by known standardized method. Acute toxicity profile of the plant was also evaluated by Lorke’s method. Total phenolic and flavonoid contents were assessed using Folin Ciocalteau and Aluminium chloride colorimetric methods; while, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2’–azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS)and ferric antioxidant reducing power (FRAP) protocols were used for their radical scavenging and total antioxidant capacities respectively. Spontaneously hypertensive rats were used for acute antihypertensive study while for the 21 days antihypertensive study, hypertension was induced by administering L-Name (40 mg/kg) for 4 weeks and, CODA 8 Non-invasive tail cuff machine was used to measure blood pressure. With the aid of a semi-auto chemistry analyzer, lipid profile of Taraxacum officinale (TO) was determined using Biosinol reagents. TOL and TOR also significantly reduced systolic, diastolic and mean arterial blood pressures up until 4 hours with the leaf part most active in single dose study using SHR model. TOL and TOR also significantly lowered systolic, diastolic and mean arterial blood pressures with the leaf part most active in 21 days study using and L-Name-induced HTN models. However, these plant extracts did not have a diuretic effect, but seems to exert its antihypertensive effects by modulating NO production and possibly bioavailability, by acting via an endothelium-dependent pathway. This study validates the traditional use of the leaf part of the plant as an antihypertensive agent.

For more than half a century cardiovascular disease has been the leading cause of death in the United States.  Aging, hypertension, and obesity are major risk factors for cardiovascular disease and clearly associated with arterial stiffness.  Arterial stiffness generates higher afterloads and diminishes coronary perfusion thereby causing ventricular hypertrophy and ischemia.  Importantly, arterial stiffness is an independent predictor of cardiovascular disease risk and all-cause mortality.   Current strategies such as inhibition of angiotensin II or angiotensin converting enzyme, reduction of smooth muscle tone, blood volume, or inflammatory mediators, and improving glucose homeostasis are effective destiffening options.  Nebivolol, a third generation beta-blocker, has unique vasodilatory characteristics and may be particularly efficacious as a destiffening agent.  Only a few studies have addressed this issue while relying on indirect, blood pressure-dependent stiffness indices precluding clear understanding of study outcomes.  There remains a need to determine the potential utility of nebivolol therapy as an arterial destiffening strategy.   Thus, we hypothesized that the combination of nebivolol and lifestyle modification would reduce central arterial stiffness in middle-aged and older hypertensive adults more than either intervention alone.  To test this hypothesis, we randomized 45 hypertensive adults to receive lifestyle modification, nebivolol, or combination for 12 weeks.  β-stiffness index, pulse wave analysis, and arterial compliance were measured at baseline and following the intervention.  No baseline differences in variables of  interest were observed between groups.  In contrast to our hypothesis, lifestyle modification, nebivolol, and combination groups had similar (P>0.05) reductions in beta-stiffness index (-1.87±0.83; -2.03±0.60; and -2.51±0.90 U), respectively, while carotid-femoral pulse wave velocity declined only in the nebivolol and combination groups.   Our findings suggest combination of nebivolol and lifestyle modification reduces arterial stiffness to a similar degree as either intervention alone in middle-aged and older hypertensive adults.  Further studies are needed to determine if the changes in arterial stiffness continue to occur or remain clinically significant over longer durations. / Ph. D.

Background. Developing countries are undergoing a process of epidemiological transition from infectious to non-communicable diseases, described by the United Nations Secretary General Ban Ki-Moon as “a public health emergency in slow motion”. One of the most prevalent of these diseases, in sub-Saharan Africa, is hypertension, which is a complex chronic condition often referred to as the “silent killer” and a key contributor to the development of cardiovascular and cerebrovascular diseases. Hypertensive patients in this setting are estimated to increase from 74.7 million in 2008 to 125.5 million in 2025, a 68% increase. There is however an important gap between emerging high-level policies and recommendations, and the near-absence of practical guidance and experience delivering long-term medical care for non-communicable diseases within resources-limited health systems. To address this gap, our study consisted of field investigations to determine the minimum health systems requirements necessary to ensure successful delivery of anti-hypertensive medications when scaling-up interventions. Methods/Design. A cross-sectional analytic study was conducted in the Western Cape Province of South Africa using a mixed method approach with two sets of semi-structured interviews and simulation modeling. One set of interviews was conducted with health professionals involved in the care of hypertensive patients within nine community health centers (five urban and four rural) to understand the challenges associated with their care. The other set was used to map and assess the current supply chain management system of antihypertensive medications and involved key informants at different levels of the process. Finally, modeling and simulation tools with ARENA Software were used to estimate minimum numbers of health workers required to ensure successful delivery of medications when scaling up interventions. Results. The study found numerous challenges affecting the care of hypertensive patients in primary health care facilities and categorized these into five interconnected dimensions: Management of the visits within the PHC facility, Adequacy of human resources, Standardization of patients’ care, Infrastructure limitations, and Patients’ responsibilities. Potential solutions to overcome these challenges were explored in order to improve the care of the hypertensive patients in the PHC facilities. Mapping of the drug supply chain management system highlighted the complexity of the system. In fact many of the issues reported fell outside of the control of the provincial health department. The need for a more single comprehensive computer system to handle most of the functions of the drug supply management system was heavily emphasized. The modeling and simulation tool with ARENA Software estimated the type and number of health care professionals needed to provide appropriate services to a certain patient population based on the set targets. The sample data used showed how one can test the impact of various changes in the processes and staffing levels to minimize waiting times while increasing the daily patients’ intake at the facility. We found that with few additional nursing staff, that are more affordable and quicker to train than medical doctors and pharmacists, one can considerably improve the performance of the facilities in the care of hypertensive patients. Discussion. This investigation has highlighted the detailed processes in place for the care of hypertensive patients in primary health care facilities, identifying the challenges in providing such care. The potential solutions suggested by the study results, if implemented, should help improve services offered and ensure that the system remains sustainable when patients’ intake increases exponentially as a result of scaled up interventions. The weaknesses of the drug supply chain management system demand immediate action. The modeling and simulation tools used in this study, if used on an ongoing basis, could create more effective planning of needed resources, although their proper utilization will require extra training for managers. Whether there is sufficient political support to ensure the resources necessary to reach the provincial health department’s hypertension target remains to be seen, and would benefit with further economic studies to estimate the cost associated with tackling the hypertension epidemic.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-08T02:43:19Z No. of bitstreams: 1 127110045.pdf: 1527824 bytes, checksum: 960729a0a23069d5d40ec997cc3034b8 (MD5) / Made available in DSpace on 2015-05-08T02:43:19Z (GMT). No. of bitstreams: 1 127110045.pdf: 1527824 bytes, checksum: 960729a0a23069d5d40ec997cc3034b8 (MD5) Previous issue date: 2014-07-17 / O gênero Cuphea, popularmente conhecido no Brasil por “sete-sangrias”, tem seu uso medicinal reconhecido devido aos efeitos diurético, hipotensor e cardioprotetor. No sul do Brasil, em região característica do bioma Pampa, foi encontrada a espécie Cuphea glutinosa Cham. & Schltdl. Embora o uso popular, esta espécie é pouco descrita na literatura. O presente trabalho tem como objetivos o estudo da composição química dos extratos de C. glutinosa e a avaliação das atividades antifúngica e anti-hipertensiva. O material vegetal foi coletado na cidade de Uruguaiana (RS, Brasil), identificado e depositado em herbário. Após secagem e trituração do material vegetal, foram obtidos os extratos hidroetanólicos através de maceração exaustiva com etanol 40% (v/v) para folhas e etanol 70% (v/v) para raízes. Para a infusão, utilizou-se água a 80oC. As análises cromatográficas foram realizadas em equipamento cromatógrafo a líquido Prominence Shimadzu, em técnica por CLAE e CLUE. Utilizou-se sistema de fase reversa, eluição por gradiente com fase móvel composta por acetonitrila:metanol (4:1) e ácido fórmico 0,1% pH 3,0, coluna C18 analítica e fast, e detecção por UV-DAD e ESI-MS. Os teores de polifenóis totais e de flavonóides foram determinados por método colorimétrico, seguindo metodologia padronizada. A atividade antifúngica in vitro foi realizada utilizando o método de microdiluição em caldo, determinando-se a CIM, in-vitro, contra diferentes isolados clínicos. Para avaliação do potencial anti-hipertensivo in vivo, foram realizadas medições da pressão sanguínea pelo método de monitoramento hemodinâmico invasivo, através da inserção de cateter na artéria carótida. Os resultados de teor de fenólicos totais indicaram predominância destes componentes em extratos obtidos de folhas e por maceração, conforme os valores obtidos: 1,8501 mg EAG/mL (folhas) e 0,8467 mg EAG/mL (raízes) para infusão, e 3,7284 mgEAG/mL (folhas) e 2,6266 mg EAG/mL (raízes) para maceração. Quanto ao teor de flavonóides, os resultados quantitativos foram: 7,0959 mg/g (folhas) e 0,5664 mg/g (raízes) para a infusão, e 7,9511 mg/g (folhas) e 0,5994 mg/g (raízes) para maceração. Na análise cromatográfica, os extratos obtidos das folhas de C. glutinosa apresentaram picos cromatográficos bem separados, em perfil reprodutível. Na determinação por CLUE-MS, os dados de íon molecular e fragmentos de massa indicaram a composição predominante em flavonóides, sugerindo-se os componentes quercetina-3-O-glicosídeo, quercetina-3- arabinosídeo, quercetina-3-glicuronídeo, isoramnetina e quercetina-5-O-β-glicopiranosídeo. Para o potencial antifúngico, os extratos das folhas e raízes apresentaram atividade in vitro contra Candida parapsilosis, Candida tropicalis e Trichosporon asahii, com CIM variando na faixa de 1,9-62,5 μg/mL. Nos testes hemodinâmicos realizados, os extratos das folhas não apresentaram efeito significativo sobre a pressão arterial. A identificação dos componentes em C. glutinosa, derivados de quercetina, torna promissora novas investigações a fim de aprofundar o conhecimento a respeito desta espécie, em especial na busca de respostas para a relatada ação anti-hipertensiva. / The Cuphea genus, popularly known in Brazil as "sete-sangrias", is used traditionally due the diuretic, hypotensive and cardioprotective effects. In southern Brazil, in characteristic region of Pampa biome, it was found the species Cuphea glutinosa Cham. & Schltdl. Although used popularly, this species is few reported in the literature. The present work aimed to study the chemical composition of extracts from C. glutinosa and to evaluate the antifungal and anti -hypertensive activities. The plant material was collected in the city of Uruguaiana (RS, Brazil), identified and deposited in a herbarium. After dryness and milling, the hydroethanolic extracts were obtained through exhaustive maceration using ethanol 40% (v/v) for leaves and ethanol 70% (v/v) for roots. The infusions were prepared using water at 80 °C. The chromatographic analyses were performed in liquid chromatography Prominence Shimadzu, for HPLC and UPLC assays. The method was conducted using reverse phase system, gradient elution with mobile phase composed by acetonitrile:methanol (4:1) and formic acid 0.1% pH 3.0, C18 analytical and fast column, and detection by UV-DAD and MS. The polyphenols and flavonoids contents were determined by colorimetric method. The in vitro antifungal activity was conducted by using the broth microdilution method, determining the MIC against different clinical isolates. For evaluation of in vivo anti-hypertensive potential, the blood pressure was measured by the method of invasive hemodynamic monitoring, through of insertion the catheter into the carotid artery. The results of phenolic content indicated the high concentration of these compounds in leaves extracts obtained by maceration: 1.8501 mgEAG/mL (leaves) and 0.8467 mgEAG/mL (roots) for infusion, and 3.7284 mgEAG/mL (leaves) and 2.6266 mgEAG/mL (roots) for maceration. For flavonoids, the contents were: 7.0959 mg/g (leaves) and 0.5664 mg/g (roots) for infusion, and 7.9511 mg/g (leaves) and 0.5994mg/g (roots) for maceration. In the chromatographic analyses, the leaf extracts from C. glutinosa presented chromatographic peaks well separated and reproducible. In the determination by UPLC-MS, the molecular ion and mass fragments indicated the predominant composition in flavonoids, suggesting the compounds quercetin-3- O-glucoside, quercetin-3-arabinoside, quercetin-3-glucuronide, isorhamnetin and quercetin-5- O-β-glucopiranoside. For the antifungal potential, the leaf and roots extracts presented activity against Candida parapsilosis, Candida tropicalis e Trichosporon asahii, with MIC values ranging 1,9-62,5 μg/mL. In the hemodynamic tests performed, the leaves extracts did not present significant effect in the arterial pressure, although a tendency in pressure reduction could be observed. The identification of quercetin derivatives in C. glutinosa becomes promisor further investigations about this species, mainly in respect to the anti-hypertensive action.

A hipertensão arterial (HA) desempenha papel determinante na ocorrência de eventos clínicos graves, havendo entretanto controvérsia quanto ao seu impacto no cotidiano do portador. A incapacidade temporária para a realização de atividades habituais, definida como uma restrição temporária na capacidade funcional habitual do indivíduo, é um indicador de saúde recomendado pela Organização Mundial da Saúde para uso em estudos populacionais. A partir do objetivo geral de investigar a associação entre hipertensão arterial e incapacidade temporária para atividades habituais, delineamos os seguintes objetivos específicos: A) Investigar se a elevação dos níveis pressóricos determina a freqüência e o período acumulado de incapacidade temporária para atividades habituais; B) Investigar se o uso de medicações anti-hipertensivas associa-se a alterações na freqüência e no período acumulado de incapacidade temporária para atividades habituais. O estudo seccional com dados de 2953 participantes obtidos através de questionário auto-administrado no Estudo Pró-Saúde, uma coorte de funcionários técnico-administrativos de universidade localizada no estado do Rio de Janeiro. A exposição foi avaliada a partir do valor aferido da PA e do uso de drogas anti-hipertensivas. Conduzimos a análise separando os participantes em 4 grupos, combinando as informações quanto à PA aferida (< ou 140/90 mmHg), e o relato de uso ou não de medicação anti-hipertensiva. O desfecho foi avaliado com a utilização de uma variável composta com informação referente à ocorrência e ao período de incapacidade. Realizamos análise multivariada através de regressão logística multinomial. Temos como resultado 690 (23,4 %) participantes foram classificados como hipertensos, e 704 (23,8 %) relataram incapacidade temporária. O relato do uso de medicação anti-hipertensiva mostrou, entre os indivíduos com PA < 140/90 mmHg, associação direta com a prevalência de incapacidade temporária de longa duração, com OR=2,25 (IC 95 %: 1,31 3,87). A presença de PA 140/90 mmHg mostrou relação inversa com a chance de incapacidade temporária de curta duração entre os indivíduos que não usavam medicação anti-hipertensiva, a qual porém não foi estatisticamente significativa (OR=0,64; IC 95 %: 0,40 1,03). Encontramos uma associação direta entre o uso de drogas anti-hipertensivas e incapacidade temporária de longa duração, a qual pode relacionar-se a efeitos adversos da medicação; os resultados sugerem também uma relação inversa entre os valores da PA e a prevalência de incapacidade de curta duração, a qual não alcançou significância estatística, e que pode estar relacionada a um fenômeno conhecido como hipoalgesia associada à HA. / Arterial hypertension (AH) plays a determinant role in the occurrence of severe clinical events; however, there are controversies about its impact on daily life. The temporary disability for daily activities, which is defined as a temporary restriction in an individuals usual level of functioning, is a health indicator proposed by the World Health Organization for utilization in population studies. To investigate the association between arterial hypertension and temporary disability for daily activities, we proposed the following specific objectives: A) To investigate whether elevated blood pressure (BP) determine the frequency or accumulated period of temporary disability for daily activities; 2) To investigate whether the use of anti-hypertensive drugs are associated with changes in the frequency or accumulated period of temporary disability for daily activities. We have a cross-sectional study with data obtained from 2953 participants who answered a self administered questionnaire in the Pro-Saude Study, a cohort of university employees in Rio de Janeiro state. The exposure was evaluated using the measured value of BP and the report of the use of anti-hypertensive drugs. We conducted the analysis classifying the participants in 4 groups, combining the information about measured BP (< or 140/90 mmHg) and the report of the use of anti-hypertensive drugs or not. The outcome was evaluated with a composite variable with information about the report and period of disability. Multivariate analyses were conducted using multinomial logistic regression. The results are 690 (23.4 %) were classified as hypertensives, and 704 (23.8 %) reported temporary disability. The use of antihypertensive drugs, among the participants with BP < 140/90 mmHg, was directly associated with the prevalence of temporary disability for daily activities for a longer period (OR=2.25, CI 95 %: 1.31 - 3.87). The presence of BP 140/90 mmHg showed an inverse relationship with the chance of temporary disability for a short period among the participants that did not use ntihypertensive drugs, not reaching statistical significance (OR=0.64; CI 95 %: 0.40 - 1.03). We found a direct association between the use of anti-hypertensive drugs and temporary disability for daily activities for a long period, which may be related to adverse effects of the drugs; the results also suggest an inverse relationship between BP values and the prevalence of temporary disability for a short period, which did not reach statistical significance, and can be related to a phenomenon known as AH-asociated hypalgesia.

A hipertensão arterial (HA) desempenha papel determinante na ocorrência de eventos clínicos graves, havendo entretanto controvérsia quanto ao seu impacto no cotidiano do portador. A incapacidade temporária para a realização de atividades habituais, definida como uma restrição temporária na capacidade funcional habitual do indivíduo, é um indicador de saúde recomendado pela Organização Mundial da Saúde para uso em estudos populacionais. A partir do objetivo geral de investigar a associação entre hipertensão arterial e incapacidade temporária para atividades habituais, delineamos os seguintes objetivos específicos: A) Investigar se a elevação dos níveis pressóricos determina a freqüência e o período acumulado de incapacidade temporária para atividades habituais; B) Investigar se o uso de medicações anti-hipertensivas associa-se a alterações na freqüência e no período acumulado de incapacidade temporária para atividades habituais. O estudo seccional com dados de 2953 participantes obtidos através de questionário auto-administrado no Estudo Pró-Saúde, uma coorte de funcionários técnico-administrativos de universidade localizada no estado do Rio de Janeiro. A exposição foi avaliada a partir do valor aferido da PA e do uso de drogas anti-hipertensivas. Conduzimos a análise separando os participantes em 4 grupos, combinando as informações quanto à PA aferida (< ou 140/90 mmHg), e o relato de uso ou não de medicação anti-hipertensiva. O desfecho foi avaliado com a utilização de uma variável composta com informação referente à ocorrência e ao período de incapacidade. Realizamos análise multivariada através de regressão logística multinomial. Temos como resultado 690 (23,4 %) participantes foram classificados como hipertensos, e 704 (23,8 %) relataram incapacidade temporária. O relato do uso de medicação anti-hipertensiva mostrou, entre os indivíduos com PA < 140/90 mmHg, associação direta com a prevalência de incapacidade temporária de longa duração, com OR=2,25 (IC 95 %: 1,31 3,87). A presença de PA 140/90 mmHg mostrou relação inversa com a chance de incapacidade temporária de curta duração entre os indivíduos que não usavam medicação anti-hipertensiva, a qual porém não foi estatisticamente significativa (OR=0,64; IC 95 %: 0,40 1,03). Encontramos uma associação direta entre o uso de drogas anti-hipertensivas e incapacidade temporária de longa duração, a qual pode relacionar-se a efeitos adversos da medicação; os resultados sugerem também uma relação inversa entre os valores da PA e a prevalência de incapacidade de curta duração, a qual não alcançou significância estatística, e que pode estar relacionada a um fenômeno conhecido como hipoalgesia associada à HA. / Arterial hypertension (AH) plays a determinant role in the occurrence of severe clinical events; however, there are controversies about its impact on daily life. The temporary disability for daily activities, which is defined as a temporary restriction in an individuals usual level of functioning, is a health indicator proposed by the World Health Organization for utilization in population studies. To investigate the association between arterial hypertension and temporary disability for daily activities, we proposed the following specific objectives: A) To investigate whether elevated blood pressure (BP) determine the frequency or accumulated period of temporary disability for daily activities; 2) To investigate whether the use of anti-hypertensive drugs are associated with changes in the frequency or accumulated period of temporary disability for daily activities. We have a cross-sectional study with data obtained from 2953 participants who answered a self administered questionnaire in the Pro-Saude Study, a cohort of university employees in Rio de Janeiro state. The exposure was evaluated using the measured value of BP and the report of the use of anti-hypertensive drugs. We conducted the analysis classifying the participants in 4 groups, combining the information about measured BP (< or 140/90 mmHg) and the report of the use of anti-hypertensive drugs or not. The outcome was evaluated with a composite variable with information about the report and period of disability. Multivariate analyses were conducted using multinomial logistic regression. The results are 690 (23.4 %) were classified as hypertensives, and 704 (23.8 %) reported temporary disability. The use of antihypertensive drugs, among the participants with BP < 140/90 mmHg, was directly associated with the prevalence of temporary disability for daily activities for a longer period (OR=2.25, CI 95 %: 1.31 - 3.87). The presence of BP 140/90 mmHg showed an inverse relationship with the chance of temporary disability for a short period among the participants that did not use ntihypertensive drugs, not reaching statistical significance (OR=0.64; CI 95 %: 0.40 - 1.03). We found a direct association between the use of anti-hypertensive drugs and temporary disability for daily activities for a long period, which may be related to adverse effects of the drugs; the results also suggest an inverse relationship between BP values and the prevalence of temporary disability for a short period, which did not reach statistical significance, and can be related to a phenomenon known as AH-asociated hypalgesia.

Os peptídeos potenciadores da bradicinina (BPPs) presentes no veneno da serpente Bothrops jararaca são oligopeptídeos ricos em prolinas. Eles foram os primeiros inibidores naturais da enzima conversora de angiotensina (ECA) descritos. As propriedades bioquímicas e farmacológicas desses peptídeos foram essenciais para o desenvolvimento do captopril, o primeiro inibidor sítio-dirigido da ECA, usado para tratar a hipertensão humana. Recentes dados têm sugerido que a atividade farmacológica dos BPPs não pode ser explicada somente pela ação inibitória da atividade da ECA e que os efeitos dos BPPs devem envolver a participação do sistema nervoso central (SNC). Nesse trabalho foi caracterizada a sinalização de Ca2+ induzida pelo BPP-10c [&#60;ENWPHPQIPP] em células neuronais obtidas de cultura primária de cérebro de ratos neonatos. As elevações na [Ca2+]i induzida por várias concentrações de BPP-10c revelaram uma curva dose-resposta atípica. A resposta máxima de transientes de [Ca2+]i foram medidas na concentração de 1 &#181;M de BPP-10c, enquanto que em concentrações mais elevadas houve um declínio das respostas de [Ca2+]i. Esse efeito foi independente da atividade do receptor de bradicinina (BK) e foi mediado por um receptor acoplado a Gi/0. A sinalização do BPP-10c levou a um aumento da produção de óxido nítrico (NO) por células neuronais, como decorrência da ativação da NOS, uma enzima Ca2+-dependente e da super-expressão da NO sintase endotelial (eNOS) e da argininosuccicinato sintase (ASS), enzima passo limitante no fornecimento de substrato para a NOS. Além disso, ensaios de afinidade com o BPP-10c revelaram além da ASS, a sinapsina como potencial alvo do BPP-10c no SNC. O fato do BPP-10c interagir com a sinapsina, proteína envolvida com a exocitose, e aumentar a produção de NO por células neuronais pode explicar a sua capacidade de induzir a liberação dos neurotransmissores, GABA e glutamato, ambos com importante papel na regulação da pressão arterial. O NO no SNC também age como neurotransmissor, regulando a atividade simpática e parassimpática. O BPP-10c produz queda da pressão da arterial e da freqüência cardíaca, indicando uma interferência direta na atividade autonômica simpática, parassimpática ou ambas, provocando mudanças no controle barorreflexo da freqüência cardíaca. De fato, esse peptídeo mostrou aumentar a sensibilidade barorreflexa de SHRs que está diminuída nesses animais quando comparados a ratos normotensos. Foi demonstrado também que o efeito do BPP-10c administrado perifericamente foi semelhante ao administrado centralmente, sugerindo que o efeito anti-hipertensivo do BPP-10c deve envolver o SNC. Dessa maneira, apesar do bem caracterizado efeito anti-hipertensivo baseado na inibição da ECA, esse trabalho evidencia a existência de um segundo mecanismo para ação do BPP-10c no controle da pressão arterial. No SNC, o BPP-10c modula a expressão da eNOS e da ASS e induz um aumento na produção de NO e liberação dos neurotransmissores, GABA e glutamato, para controlar a atividade simpática e/ou parassimpática que reflete no aumento da sensibilidade do barorreflexo de SHRs. Sendo assim, as características bioquímicas e farmacológicas do BPP-10c abrem perspectivas para o desenvolvimento de fármacos baseado em um novo alvo terapêutico. / Pyroglutamyl proline-rich oligopeptides, denominated bradykinin-potentiating peptides (BPPs), present in the venom of the viper Bothrops jararaca were the first described naturally occurring angiotensine-converting enzyme (ACE) inhibitors. The biochemical and pharmacological properties of theses peptides were essential for the development of captopril, the first active site-directed inhibitor of ACE, currently used to treat human hypertension. Recent data have suggested that the pharmacological activity of BPPs could not only be explained by their inhibitory action on the ACE activity and that BPPmediated effects may involve the central nervous system. In this work, we have characterized BPP-10c [&#60;ENWPHPQIPP]-induced calcium signaling in neuronal cells obtained as primary culture from day 1 of postnatal rat brain. Elevations of [Ca2+]i induced by increasing concentrations of BPP-10c revealed an atypical dose-response curve. Maximal [Ca2+]i peak values were measured at 1 &#181;M BPP-10c concentration, while further raising BPP-10c concentrations led to a decline of [Ca2+]i responses. This effect was independent from kinin-B2 receptor activity and was mediated by a yet unknown Gi/0 protein-coupled receptor. BPP-10c signaling promoted an increase of nitric oxide (NO) production in neuronal cells, as consequence of Ca2+-dependent NO synthase activation and upregulated gene expression of endothelial NO synthase (eNOS) and argininosuccicinato synthase (ASS), a limiting step enzyme in the NOcitrulline cycle. Furthermore, affinity chromatography assays revealed ASS and synapsin as potential binding partners of BPP-10c in the CNS. In view of that BPP-10c interacts with synapsin, a protein involved with exocytosis, and induces NO production in neuronal cells, these data could explain its capacity of inducing release of the neurotransmitters GABA and glutamate with important roles in blood pressure regulation. NO also acts as neurotransmitter in the CNS, thereby regulating sympathetic and parasympathetic activities. The presence of BPP-10c also mediates reduction of arterial pressure and heart rate suggesting direct interference of BPP action with autonomic sympathetic and/or parasympathetic activity and the baroreflex control of the heart rate. In agreement, this peptide led to increased baroreflex sensitivity of spontaneous hypertensive rats. We have also demonstrated that the BPP-10c-mediated anti-hypertensive effect was similar following peripheral or central administration, suggesting the participation of the CNS in this process. The existence of a second mechanism for BPP-10c action on blood pressure control as new therapeutic target which is independent from ACE inhibition shall initiate novel approaches for antihypertensive drugs.

Os peptídeos potenciadores da bradicinina (BPPs) presentes no veneno da serpente Bothrops jararaca são oligopeptídeos ricos em prolinas. Eles foram os primeiros inibidores naturais da enzima conversora de angiotensina (ECA) descritos. As propriedades bioquímicas e farmacológicas desses peptídeos foram essenciais para o desenvolvimento do captopril, o primeiro inibidor sítio-dirigido da ECA, usado para tratar a hipertensão humana. Recentes dados têm sugerido que a atividade farmacológica dos BPPs não pode ser explicada somente pela ação inibitória da atividade da ECA e que os efeitos dos BPPs devem envolver a participação do sistema nervoso central (SNC). Nesse trabalho foi caracterizada a sinalização de Ca2+ induzida pelo BPP-10c [&#60;ENWPHPQIPP] em células neuronais obtidas de cultura primária de cérebro de ratos neonatos. As elevações na [Ca2+]i induzida por várias concentrações de BPP-10c revelaram uma curva dose-resposta atípica. A resposta máxima de transientes de [Ca2+]i foram medidas na concentração de 1 &#181;M de BPP-10c, enquanto que em concentrações mais elevadas houve um declínio das respostas de [Ca2+]i. Esse efeito foi independente da atividade do receptor de bradicinina (BK) e foi mediado por um receptor acoplado a Gi/0. A sinalização do BPP-10c levou a um aumento da produção de óxido nítrico (NO) por células neuronais, como decorrência da ativação da NOS, uma enzima Ca2+-dependente e da super-expressão da NO sintase endotelial (eNOS) e da argininosuccicinato sintase (ASS), enzima passo limitante no fornecimento de substrato para a NOS. Além disso, ensaios de afinidade com o BPP-10c revelaram além da ASS, a sinapsina como potencial alvo do BPP-10c no SNC. O fato do BPP-10c interagir com a sinapsina, proteína envolvida com a exocitose, e aumentar a produção de NO por células neuronais pode explicar a sua capacidade de induzir a liberação dos neurotransmissores, GABA e glutamato, ambos com importante papel na regulação da pressão arterial. O NO no SNC também age como neurotransmissor, regulando a atividade simpática e parassimpática. O BPP-10c produz queda da pressão da arterial e da freqüência cardíaca, indicando uma interferência direta na atividade autonômica simpática, parassimpática ou ambas, provocando mudanças no controle barorreflexo da freqüência cardíaca. De fato, esse peptídeo mostrou aumentar a sensibilidade barorreflexa de SHRs que está diminuída nesses animais quando comparados a ratos normotensos. Foi demonstrado também que o efeito do BPP-10c administrado perifericamente foi semelhante ao administrado centralmente, sugerindo que o efeito anti-hipertensivo do BPP-10c deve envolver o SNC. Dessa maneira, apesar do bem caracterizado efeito anti-hipertensivo baseado na inibição da ECA, esse trabalho evidencia a existência de um segundo mecanismo para ação do BPP-10c no controle da pressão arterial. No SNC, o BPP-10c modula a expressão da eNOS e da ASS e induz um aumento na produção de NO e liberação dos neurotransmissores, GABA e glutamato, para controlar a atividade simpática e/ou parassimpática que reflete no aumento da sensibilidade do barorreflexo de SHRs. Sendo assim, as características bioquímicas e farmacológicas do BPP-10c abrem perspectivas para o desenvolvimento de fármacos baseado em um novo alvo terapêutico. / Pyroglutamyl proline-rich oligopeptides, denominated bradykinin-potentiating peptides (BPPs), present in the venom of the viper Bothrops jararaca were the first described naturally occurring angiotensine-converting enzyme (ACE) inhibitors. The biochemical and pharmacological properties of theses peptides were essential for the development of captopril, the first active site-directed inhibitor of ACE, currently used to treat human hypertension. Recent data have suggested that the pharmacological activity of BPPs could not only be explained by their inhibitory action on the ACE activity and that BPPmediated effects may involve the central nervous system. In this work, we have characterized BPP-10c [&#60;ENWPHPQIPP]-induced calcium signaling in neuronal cells obtained as primary culture from day 1 of postnatal rat brain. Elevations of [Ca2+]i induced by increasing concentrations of BPP-10c revealed an atypical dose-response curve. Maximal [Ca2+]i peak values were measured at 1 &#181;M BPP-10c concentration, while further raising BPP-10c concentrations led to a decline of [Ca2+]i responses. This effect was independent from kinin-B2 receptor activity and was mediated by a yet unknown Gi/0 protein-coupled receptor. BPP-10c signaling promoted an increase of nitric oxide (NO) production in neuronal cells, as consequence of Ca2+-dependent NO synthase activation and upregulated gene expression of endothelial NO synthase (eNOS) and argininosuccicinato synthase (ASS), a limiting step enzyme in the NOcitrulline cycle. Furthermore, affinity chromatography assays revealed ASS and synapsin as potential binding partners of BPP-10c in the CNS. In view of that BPP-10c interacts with synapsin, a protein involved with exocytosis, and induces NO production in neuronal cells, these data could explain its capacity of inducing release of the neurotransmitters GABA and glutamate with important roles in blood pressure regulation. NO also acts as neurotransmitter in the CNS, thereby regulating sympathetic and parasympathetic activities. The presence of BPP-10c also mediates reduction of arterial pressure and heart rate suggesting direct interference of BPP action with autonomic sympathetic and/or parasympathetic activity and the baroreflex control of the heart rate. In agreement, this peptide led to increased baroreflex sensitivity of spontaneous hypertensive rats. We have also demonstrated that the BPP-10c-mediated anti-hypertensive effect was similar following peripheral or central administration, suggesting the participation of the CNS in this process. The existence of a second mechanism for BPP-10c action on blood pressure control as new therapeutic target which is independent from ACE inhibition shall initiate novel approaches for antihypertensive drugs.