Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 125-144).

Orientador: Heitor Moreno Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T00:33:13Z (GMT). No. of bitstreams: 1 Girioli_SamiraUbaid_D.pdf: 2811337 bytes, checksum: bc9374b0216cba3ee57f1b107392c0e0 (MD5) Previous issue date: 2009 / Resumo: Segundo o VII JNC e V Diretrizes Brasileiras de Hipertensão Arterial, a hipertensão arterial resistente (HAR) é definida como sendo a elevação persistente dos níveis pressóricos (= 140/90 mmHg) a despeito de tratamento farmacológico tríplice, pleno, incluindo diuréticos, em pacientes com boa adesão e sem causas secundárias de hipertensão arterial ou pseudo-hipertensão. O excesso ou escape de aldosterona pode ocorrer após tratamento crônico com IECA, BRA ou diuréticos tiazídicos, comumente utilizados nestes pacientes ou por hiperaldosteronismo primário não diagnosticado. A espironolactona tem sido apontada como fármaco indispensável no tratamento de HAR por melhorar os níveis pressóricos, mas pouco se sabe sobre a pressão arterial (PA), função endotelial e remodelamento cardiovascular avaliados simultaneamente após sua utilização. O objetivo deste estudo foi avaliar a pressão arterial, a função endotelial, o remodelamento cardiovascular e a função diastólica em hipertensos refratários antes e após a utilização de antagonista de aldosterona, espironolactona, em associação ao tratamento anti-hipertensivo otimizado e individualizado em centro de referência em HAR por 6 meses. Após triagem e adesão rigorosa, 71 pacientes encaminhados ao nosso serviço como hipertensos resistentes foram seqüencialmente incluídos no estudo, após avaliação e caracterização como hipertensos resistentes (HAR, n=39) ou hipertensos controlados (HAC, n=32). O grupo controle foi constituído por pacientes normotensos (CONT, n=37). Anti-hipertensivos eram fornecidos integralmente. Ecocardiograma, Teste de vasodilatação mediada pelo fluxo (VMF), espessura íntima-média de carótidas (IMT), dosagens bioquímicas de concentrações de renina e aldosterona plasmáticas, sódio e potássio séricos e urinários foram realizados na fase inicial (pré-espiro), seguida por associação de espironolactona 25mg/dia ao tratamento anti-hipertensivo por 6 meses (apenas para os grupos HAR e HAC) . Subsequentemente, estes parâmetros foram reavaliados (fase pós-espiro). Após 6 meses de espironolactona, os grupos HAR e HAC apresentaram redução da PA (p<0,001 para PAS e PAD). O grupo HAR apresentou melhora da função endotelial dependente (p<0,001) e independente do endotélio (p=0,007). Os grupos HAR e HAC apresentaram melhora da hipertrofia ventricular esquerda p<0,001) e melhora da função diastólica (índice Kappa HAR: 0,219 e índice Kappa HAC: 0,392) em 7,69% e 15,62%, respectivamente. Os grupos HAR e HAC apresentaram elevação da aldosterona plasmática (p<0,05). A otimização do tratamento da HAR com a associação de espironolactona em pequenas doses, reduz PA, melhora função endotelial, melhora hipertrofia ventricular esquerda e função diastólica a despeito da presença de excesso ou "escape" de aldosterona. / Abstract: According to JOINT VII and V Brazilian Guidelines of Hypertension, resistant hypertension (RH) is defined, as a persistent elevation of blood pressure (= 140/90 mmHg) despite the use of a triple drug regimen at maximal doses including a diuretic, in patients with good compliance and without secondary causes of hypertension or pseudo-hypertension. Aldosterone excess or "escape" can occur after chronic treatment with ACEI, ARB or thiazide-type diuretics, commonly used by these patients or in undiagnosed primary aldosteronism. Spironolactone is thought to be an essential drug in RH treatment because it improves blood pressure, but there are few available data about blood pressure, endothelial function and cardiovascular remodeling evaluated simultaneously with its use. The aim of this study was to assess blood pressure, endothelial function, cardiovascular remodeling and diastolic function in resistant hypertensive patients before and after the use of an aldosterone antagonist, spironolactone, for a six-month period in association with individualized and optimized antihypertensive treatment in a RH reference clinic. After confirming compliance to treatment, 71 hypertensive patients attending our service were included in the study as resistant hypertensive (RH, n = 39) or controlled hypertensive (CH, n = 32) patients. The control group was formed of normotensive patients (CONT, n = 37). All antihypertensive drugs were supplied. Echocardiography, flow-mediated vasodilation, carotid intima-media wall thickness, plasma renin and aldosterone concentrations, plasma and urinary sodium and potassium concentrations were measured at baseline (pre-spironolactone phase), followed by an association of 25 mg/d spironolactone with existing antihypertensive drugs for 6 months (only to RH and CH groups). Subsequently these parameters were reassessed (post-spironolactone phase). After 6 months of spironolactone, the RH and CH groups presented with a reduction in blood pressure (p<0.001 for both systolic and diastolic blood pressures). The RH group had improved endothelial function, both endothelium-dependent (p<0.001) and independent (p = 0.007). RH and CH groups presented with improved left ventricular hypertrophy (p<0.001) and diastolic function (Kappa index RH: 0.219 and Kappa index CH: 0.392) in 7.69% and 15.62%, respectively. There were increases in aldosterone concentrations for RH and CH groups (p< 0.05). Optimized RH treatment with low doses of spironolactone reduces blood pressure and improves endothelial function, left ventricular hypertrophy and diastolic function despite of aldosterone excess or "escape". / Doutorado / Doutor em Farmacologia

La spironolactone (SP), est un antagoniste de l’aldostérone, utilisée dans le traitement de l’hypertension. Le traitement de cellules par la SP induit la dégradation spécifique de la protéine XPB (Alekseev et al., 2014). L’utilisation de la SP sur des lignées lymphocytaires (Jurkat T) et des lymphocytes primaires issus du sang (CD4+ activées), préalablement infectées par le VIH (type 1 ou type 2), entraîne une forte dégradation de la protéine XPB et une inhibition importante de l’infection virale. Pour confirmer la spécificité de la spironolactone sur la réplication du VIH, nous avons utilisé en parallèle l’éplérénone, analogue structurale de la spironolactone incapable de dégrader la protéine XPB. A contrario, lorsque l’on traite les cellules avec l’éplérénone, l’infection virale n’est pas inhibée. Par ailleurs, le traitement par la spironolactone a mis en évidence un effet sur l’activation de la transcription du promoteur LTR du VIH dépendante de Tat, effet qui n’est pas observé si le LTR est activé via des voies alternes (PMA et TNF). La quantification des ARN cellulaires et viraux a montré le rôle spécifique de l’action de la SP sur la transcription du promoteur LTR en présence de la protéine Tat. La spironolactone est incapable d’inhiber la transcription de promoteurs viraux différents du LTR du VIH. La spironolactone est également capable d’inhiber la réactivation de la transcription à partir du LTR du VIH dans un modèle contenant un provirus latent. Cette molécule ouvre de nouvelles perspectives concernant les molécules inhibitrices de la transcription virale et met en lumière le rôle de cofacteur de la protéine XPB dans l’infection par le VIH. / Spironolactone (SP) is an aldosterone antagonist used in hypertension treatment for many years. SP treatment is responsible for a rapid and specific degradation of the XPB protein (Alekseev et al., 2014). Jurkat and primary CD4 + T cells infected by HIV-1 or HIV-2 and treated by SP show a strong degradation of the XPB protein and an important inhibition of viral infection. To confirm specificity of SP action on HIV, we have used a structural analogue of SP, Eplerenone (EPL), which can’t degrade XPB. On the contrary, EPL is unable to inhibit infection of cells previously infected by HIV. Otherwise, SP inhibition of HIV seems to be specific of Tat dependent transcription from the HIV promoter, because activation of this promoter with PMA or TNF is not affected by SP. Quantification of viral and cellular RNA show that only LTR transcription is affected by SP. Transcription of other promoters was measured in presence of SP and Tat but no inhibition of gene transcription has been observed. Finally, SP is also able to inhibit HIV LTR reactivation from latently infected T cells. This drug appears as a new anti-HIV compound and gives new perspectives concerning transcriptional inhibitors of HIV replication. This molecule also highlights the cofactor role of XPB during HIV replication in natural target cells.

O aumento do estresse oxidativo e da atividade das metaloproteinases contribui para as alterações vasculares estruturais e funcionais presentes na hipertensão renovascular. O objetivo desse trabalho foi verificar se o tratamento com espironolactona, hidroclorotiazida, ou ambas as drogas modificam as alterações presentes no modelo dois-rins, um-clipe de hipertensão renovascular na pressão arterial, incluindo-se remodelamento da aorta, alterações de reatividade vascular, estresse oxidativo e níveis e atividade da metaloproteinase-2 da matriz extracelular (MMP-2). Animais controles operados ou ratos submetidos à estenose da artéria renal foram tratados com o veículo, espironolactona (25 mg.kg-1dia-1), hidroclorotiazida (20 mg.kg-1dia-1), ou a combinação dos dois medicamentos para oito semanas. A pressão arterial sistólica foi monitorada semanalmente por pleitismografia de cauda. Anéis de aorta foram isolados para avaliar o relaxamento vascular dependente e independente do endotélio. A análise morfométrica da parede da aorta foi realizada em coloração de hematoxilina/eosina. Foram avaliados a produção do ânion superóxido na aorta pela -nicotinamida adenina dinucleotídeo fosfato oxidase vascular, a peroxidação lipídica plasmática, medida como substâncias reativas ao ácido tiobarbitúrico, os níveis e atividade de MMP-2 determinados por zimografia em gel e fluorimetria em extrato de aorta, imuno-histoquímica e zimografia situ. O tratamento com espironolactona, hidroclorotiazida, ou a combinação das drogas atenuou a hipertensão arterial, reverteu a disfunção endotelial, atenuou o remodelamento vascular da aorta, assim como o aumento no estresse oxidativo, e reduziu os níveis e a atividade da MMP-2 induzidos pela hipertensão. Estes resultados sugerem que a espironolactona e hidroclorotiazida, isoladamente ou em combinação, produzem efeitos antioxidantes e diminuem o aumento da atividade da MMP-2, melhorando assim a disfunção vascular e remodelamento encontrados nesse modelo de hipertensão renovascular. / Increased oxidative stress and upregulation of matrix metalloproteinases may cause structural and functional vascular changes in renovascular hypertension. The aim of this work was to examine whether the treatment with spironolactone, hydrochlorothiazide, or both drugs modify two-kidney,one clip hypertensioninduced changes in arterial blood pressure, aortic remodeling, vascular reactivity, oxidative stress, and MMPs levels/activity. Sham operated or hypertensive rats were treated with vehicle, spironolactone (25 mg.kg-1day-1), hydrochlorothiazide (20 mg.kg-1day-1), or the combination of the two drugs for eight weeks. Systolic blood pressure was monitored weekly by tail-cuff plethysmography. Aortic rings were isolated to assess endothelium dependent and independent relaxations. Morphometry of the aortic wall was carried out in hematoxylin/eosin sections. Aortic nicotinamide adenine dinucleotide phosphate oxidase activity and superoxide production was evaluated. Formation of reactive oxygen species was measured in plasma as thiobarbituric acid reactive substances. Aortic metalloproteinase-2 levels and activity were determined by gelatin and in situ zymography, fluorimetry, and immunohistochemistry. Treatment with spironolactone, hydrochlorothiazide, or the combination attenuated two-kidney, one-clip induced hypertension and reversed the endothelial dysfunction, reversed the vascular aortic remodeling, attenuated hypertension-induced increases in oxidative stress, and reduced metalloproteinase-2 levels/activity induced by hypertension. These findings suggest that spironolactone or hydrochlorothiazide, alone or combined, produce antioxidant effects and decrease renovascular hypertension-induced MMP-2 upregulation, thus improving the vascular dysfunction and remodeling found in this model of hypertension.

With a growing ageing population decline in physical function has become a major public health issue, as it is associated with disability in later life. Recent evidence suggests that blockade of the renin-angiotension-aldosterone system may have a role in improving physical function in older people.We hypothesised that inhibition of the renin-angiotensin-aldosterone system with spironolactone would improve physical function in older people without heart failure. In a double-blind, randomised controlled clinical trial 120 participants, aged &gt;65 years with functional impairment were randomized to receive 25mg spironolactone or placebo for 20 weeks. The primary outcome was the change in six-minute walking distance over 20 weeks. Secondary outcomes were change in Timed-Get-Up and Go test, Incremental Shuttle Walk Test, measures of health related quality of life (EuroQol health questionnaire and Functional Limitation Profile) and measures of psychological state (Hospital Anxiety and Depression Scale). Outcomes measures were repeated at 10 and 20 weeks.Participant mean age was 75 years (SD 6), 65/120 (54%) were male. Only 8/120 participants (6.6%) dropped out (5 from the placebo group, 3 from the spironolactone group). Of the 112 participants who completed the study 95% (106/112) remained on medication at 20 weeks. There was no significant change in six minute walking distance at 20 weeks with a -3.2 (95% CI -28.9, 22.5) metres difference between the spironolactone group related to the placebo group (p=0.81). There was however a significant improvement in quality of life at 20 weeks (a secondary outcome) with a rise in EuroQol EQ-5D score of 0.10 (95% CI 0.03, 0.18) in the spironolactone group relative to the placebo group (p=&lt;0.01). There were no significant changes between groups in the other secondary outcomes. This trial found that spironolactone was safe and well tolerated, but did not improve physical function in older people who did not have heart failure. Quality of life improved, but the biological plausibility and possible mechanisms for this require further study.

Purpose: Cardiovascular events and complications are the major causes of death in patients with end-stage renal disease (ESRD)¹⁻³. Antihypertensive agents that block the renin-angiotensin-aldosterone system (RAAS) are considered first-line therapy in patients with ESRD as these patients have a propensity for RAAS overactivation⁴⁻⁷. Studies show that aldosterone receptor blockade reduces BP in patients with chronic kidney disease (CKD) and helps prevent negative outcomes from continued renal cellular damage⁸⁻¹⁰. Spironolactone, an aldosterone antagonist, has the potential to provoke hyperkalemia. Consequently, current guidelines do not recommend spironolactone to manage hypertension in ESRD because of this risk⁶⁻⁷. Our primary objectives were to determine the change in BP and serum potassium levels following spironolactone use. Methods: This study was a retrospective, pre-post cohort study in ESRD patients with difficult-to-control BP receiving HD. Patients prescribed spironolactone (25 mg to 50 mg) between January 2009 and January 2013 were identified using an e-prescribing record from three HD clinics in San Antonio, TX. Patients were included if they were prescribed spironolactone as 'add-on' therapy to control BP for at least 8 weeks. Results: Seventy patients were evaluated and the majority of them were overweight, diabetic, Hispanic females with a mean 65 years of age. Mean SBP and DBP decreased from baseline to week 8 [-20.74 mmHg (p < 0.0001) and -9.7 mmHg (p < 0.0426), respectively]. Mean serum potassium levels increased by an average of 0.18 mEq/L (4.5 mEq/L to 4.68 mEq/L, p = 0.09). Data analysis revealed that only 9 of 70 patients had a serum potassium level > 5.5 mEq/L at week 8. There were no adverse cardiac events reported as a result of these potassium concentrations. A two-fold decrease in SBP was seen in patients with a body mass index (BMI) > 25 kg/m² compared to patients with a BMI of ≤ 25 kg/m². At the end of the study, 23 patients (33%) achieved the goal BP for healthy adults of < 140/90 mmHg. Conclusion: These findings demonstrated that using spironolactone use in ESRD patients receiving HD can be effective and safe. / text

O aumento do estresse oxidativo e da atividade das metaloproteinases contribui para as alterações vasculares estruturais e funcionais presentes na hipertensão renovascular. O objetivo desse trabalho foi verificar se o tratamento com espironolactona, hidroclorotiazida, ou ambas as drogas modificam as alterações presentes no modelo dois-rins, um-clipe de hipertensão renovascular na pressão arterial, incluindo-se remodelamento da aorta, alterações de reatividade vascular, estresse oxidativo e níveis e atividade da metaloproteinase-2 da matriz extracelular (MMP-2). Animais controles operados ou ratos submetidos à estenose da artéria renal foram tratados com o veículo, espironolactona (25 mg.kg-1dia-1), hidroclorotiazida (20 mg.kg-1dia-1), ou a combinação dos dois medicamentos para oito semanas. A pressão arterial sistólica foi monitorada semanalmente por pleitismografia de cauda. Anéis de aorta foram isolados para avaliar o relaxamento vascular dependente e independente do endotélio. A análise morfométrica da parede da aorta foi realizada em coloração de hematoxilina/eosina. Foram avaliados a produção do ânion superóxido na aorta pela -nicotinamida adenina dinucleotídeo fosfato oxidase vascular, a peroxidação lipídica plasmática, medida como substâncias reativas ao ácido tiobarbitúrico, os níveis e atividade de MMP-2 determinados por zimografia em gel e fluorimetria em extrato de aorta, imuno-histoquímica e zimografia situ. O tratamento com espironolactona, hidroclorotiazida, ou a combinação das drogas atenuou a hipertensão arterial, reverteu a disfunção endotelial, atenuou o remodelamento vascular da aorta, assim como o aumento no estresse oxidativo, e reduziu os níveis e a atividade da MMP-2 induzidos pela hipertensão. Estes resultados sugerem que a espironolactona e hidroclorotiazida, isoladamente ou em combinação, produzem efeitos antioxidantes e diminuem o aumento da atividade da MMP-2, melhorando assim a disfunção vascular e remodelamento encontrados nesse modelo de hipertensão renovascular. / Increased oxidative stress and upregulation of matrix metalloproteinases may cause structural and functional vascular changes in renovascular hypertension. The aim of this work was to examine whether the treatment with spironolactone, hydrochlorothiazide, or both drugs modify two-kidney,one clip hypertensioninduced changes in arterial blood pressure, aortic remodeling, vascular reactivity, oxidative stress, and MMPs levels/activity. Sham operated or hypertensive rats were treated with vehicle, spironolactone (25 mg.kg-1day-1), hydrochlorothiazide (20 mg.kg-1day-1), or the combination of the two drugs for eight weeks. Systolic blood pressure was monitored weekly by tail-cuff plethysmography. Aortic rings were isolated to assess endothelium dependent and independent relaxations. Morphometry of the aortic wall was carried out in hematoxylin/eosin sections. Aortic nicotinamide adenine dinucleotide phosphate oxidase activity and superoxide production was evaluated. Formation of reactive oxygen species was measured in plasma as thiobarbituric acid reactive substances. Aortic metalloproteinase-2 levels and activity were determined by gelatin and in situ zymography, fluorimetry, and immunohistochemistry. Treatment with spironolactone, hydrochlorothiazide, or the combination attenuated two-kidney, one-clip induced hypertension and reversed the endothelial dysfunction, reversed the vascular aortic remodeling, attenuated hypertension-induced increases in oxidative stress, and reduced metalloproteinase-2 levels/activity induced by hypertension. These findings suggest that spironolactone or hydrochlorothiazide, alone or combined, produce antioxidant effects and decrease renovascular hypertension-induced MMP-2 upregulation, thus improving the vascular dysfunction and remodeling found in this model of hypertension.

Orientadores: Heitor Moreno Junior, Maricene Sabha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T18:07:53Z (GMT). No. of bitstreams: 1 Favero_FabriciodeFaveri_M.pdf: 1407421 bytes, checksum: 06435063a3f8e02cab7d2728ccdd05e0 (MD5) Previous issue date: 2009 / Resumo: Introdução: Em pacientes hipertensos, há uma relação entre morbidade e mortalidade e dano arterial, afetando um ou vários órgãos como: coração, cérebro, rins e outros. Portanto, lesões arteriais requerem uma avaliação precoce dos fatores de risco cardiovascular, uma vez que são os maiores contribuintes para doenças cardiovasculares. Entre os métodos simples e não invasivos de avaliação da rigidez arterial, a Velocidade de Onda de Pulso (VOP) é amplamente utilizada como um índice de rigidez arterial e elasticidade, sendo preciso, simples, reproduzível e habitualmente aplicado em estudos clínicos. Objetivos: Detectar alterações na velocidade de onda de pulso (VOP) em pacientes com hipertensão arterial resistente e hipertensos controlados quando comparados a indivíduos não hipertensos, durante dois períodos. Materiais e Métodos: este estudo avaliou 129 pacientes: 42 com hipertensão arterial resistente (HAR), 46 com hipertensão arterial controlada (HAC) e 41 indivíduos sem doença hipertensiva, representando o grupo controle (CT). O estudo foi realizado em duas fases - inicialmente com terapia medicamentosa otimizada (fase 0) e, após 6 meses, os pacientes foram reavaliados com o tratamento habitual associado à espironolactona na dose de 25 mg/dia (fase 1). Resultados: Na fase 0, a VOP do grupo CT (7,8±1,06 m/s) foi inferior a do grupo HAC (8,6±1,26 m/s), que mostrou-se inferior a do grupo HAR (9,3±1,5 m/s). Na fase 1, os resultados seguiram o mesmo padrão: grupo CT = 7,8±1,12 m/s, grupo HAC = 8,42±1,19 m/s e grupo HAR = 9,4±1,45 m/s. Conclusões: As alterações da VOP encontradas nos grupos HAR e HAC sugerem um aumento na rigidez arterial desses grupos. Os resultados indicam que valores mais altos de VOP estão associados a níveis de hipertensão moderado a severo. A associação da espironolactona não alterou os valores da VOP, aparentemente, não interferindo no remodelamento vascular. No que se refere à VOP, são necessários estudos adicionais com "n" maior de pacientes, por um período mais prolongado. / Abstract: Introduction: In hypertensive patients, there is a relationship between morbidity and mortality and arterial damage, affecting one or several organs like: heart, brain, kidney and others. Therefore, large arterial injuries require early evaluation of cardiovascular risk factors, once they are major contributors to cardiovascular diseases. Among the simple and non-invasive methods of arterial assessment, the Pulse Wave Velocity (PWV) measurement is widely utilized as an index of arterial stiffness and elasticity, for being accurate, simple, reproducible and usually applied in clinical trials. Objectives: To detect PWV alterations in arterial resistant and controlled hypertensive patients when compared to subjects with no hypertensive disease, during two periods. Materials and Methods : This study assessed 129 subjects: 42 Resistant Hypertensive (RH) patients, 46 Controlled Hypertensive (CH) patients and 41 subjects with no hypertensive disease, representing the Control group (CT). The study was performed in two phases - it began at an initial therapeutic optimization time (phase 0) and, after 6 months, patients were reassessed with their usual treatment associated to a spironolactone dose of 25 mg/day (phase 1). Results: In phase 0, PWV value of the CT group (7,8±1,06 m/s) was lower than the CH group (8,6±1,26m/s), which was lower than the RH group (9,3±1,5 m/s). In phase 1, results followed the same pattern: CT group = 7,8±1,12 m/s, CH group = 8,42±1,19 m/s and RH group = 9,4±1,45 m/s. Conclusions: PWV alterations found in groups RH and CH suggest an increase in arterial stiffness in these groups. Results indicate that higher PWV values are associated to moderate-to-severe levels of hypertension. The association of spironolactone did not alter PWV values, apparently, not interfering in vascular remodeling. Regarding PWV, additional studies are necessary with an increased number of patients, for a longer period. / Mestrado / Mestre em Farmacologia

Orientador: Ana Paula Couto Davel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T14:07:47Z (GMT). No. of bitstreams: 1 Victorio_JamairaAparecida_M.pdf: 1155350 bytes, checksum: eab5bb2760f0d9abd7c5e93ac2b95b51 (MD5) Previous issue date: 2014 / Resumo: A hiperativação dos receptores ß-adrenérgicos (ß-AR) tem importante papel na patogênese de doenças cardiovasculares que cursam com hiperatividade simpática. Dentre os seus efeitos, sugere-se a indução da síntese e liberação de angiotensina II e de aldosterona sistemicamente. A hiperativação dos receptores ß-AR pode ser mimetizada pelo tratamento crônico com isoproterenol (ISO). Já foi demonstrado que o antagonismo do receptor AT1 de angiotensina II ou do receptor de mineralocorticoides (MR) previne parcialmente o remodelamento cardíaco induzido pelo ISO. Entretanto, ainda não está elucidado o envolvimento da angiotensina II e da aldosterona nos efeitos vasculares causados pela hiperativação dos receptores ß-AR. Assim, o objetivo do presente estudo foi investigar as vias de sinalização dos receptores AT1 e MR nas alterações vasculares causadas pelo tratamento por 7 dias com ISO em aorta de ratos, assim como os mecanismos envolvidos. Ratos Wistar (3 meses) foram tratados com ISO (0,3 mg/kg/dia, s.c.) ou veículo (CT) e co-tratados ou não com o antagonista do receptor AT1 losartan (LOS; 40 mg/kg/dia) ou com o antagonista do receptor MR espironolactona (ESP; 200 mg/kg/dia). O tratamento com ISO causou hipertrofia ventricular sem alterações hemodinâmicas, e o co-tratamento com LOS ou ESP atenuaram o remodelamento ventricular observado. Na aorta do grupo ISO observou-se um aumento da resposta máxima à fenilefrina associado à redução da biodisponibilidade de óxido nítrico (NO) e aumento de ânion superóxido, os quais foram prevenidos pelo co-tratamento com ESP, mas não com LOS. O efeito preventivo da ESP sobre a reatividade vascular da aorta dos ratos ISO foi acompanhado de aumento da expressão proteica da HSP90, a qual foi reduzida no grupo ISO. Além disso, a ESP preveniu o aumento da expressão proteica de ß-arrestina, Gai, p-Src, ERK1/2, p- ERK1/2 e gênica de osteopontina na aorta deste grupo. As concentrações plasmáticas de corticosterona ou aldosterona não foram alteradas entre os grupos avaliados. Em conjunto, os dados sugerem que o antagonismo do receptor MR com o uso de espironolactona previne o aumento da resposta contrátil à fenilefrina observada em aorta de ratos tratados com ISO, associado a: aumento da biodisponibilidade de NO e redução do estresse oxidativo; aumento da expressão de HSP90, a qual estabiliza a forma dimérica da eNOS; e prevenção do aumento da expressão proteica de ß- arrestina, Gai1,2, p-Src, ERK1/2 e p-ERK1/2 e gênica de osteopontina, vias de sinalização de estresse oxidativo e prejuízo da função endotelial / Abstract: ß-adrenergic (ß¿AR) receptors overstimulation plays an important role in the pathogenesis of cardiovascular diseases concurrent with sympathetic overactivity. It has been suggested to increase plasma levels of angiotensin II and aldosterone. In line with this, angiotensin II/AT1 receptor or mineralocoticoid (MR) receptor antagonism partially prevents the cardiac remodeling induced by ß-AR overstimulation mediated by isoproterenol (ISO) administration. However the implication of angiotensin II or aldosterone on vascular effects provoked by ß¿AR overstimulation is not yet elucidated. So, the aim of the present study was to investigate the AT1 and MR receptor signaling pathway on vascular alterations caused by 7-day ISO treatment on rat aorta, as well as the mechanisms involved. For this, male Wistar rats (3-month-old) were treated with ISO (0.3 mg/kg/day, s.c.) or vehicle (CT) and co-treated or not with AT1 antagonist losartan (LOS; 40 mg/kg/day, v.o.) or MR receptor antagonist spironolactone (ESP; 200 mg/kg/day, v.o.). The ISO treatment resulted in ventricular hypertrophy without hemodynamic alterations, and LOS or ESP co-treatment attenuated the ventricular remodeling of ISO group. ISO aorta showed an increased phenylephrine maximum response associated with a decreased nitric oxide (NO) bioavailability and an increased in superoxide anion; both effects were prevented by ESP co-treatment, but not by LOS. Beneficial effects of ESP on vascular reactivity of aorta from ISO-treated rats were accompanied by an increased HSP90 protein expression, which was reduced in ISO group. Moreover, ESP prevented the increased protein expression of ß-arrestin, Gai, p- Src, ERK1/2 and p-ERK1/2 and osteopontina gene expression in the aorta from ISO group. Plasma corticosterone and aldosterone were not changed between the groups. In conclusion, our results suggest that spironolactone, an MR receptor antagonist prevented the increased phenylephrine contractile response in aorta from ISO-treated rats, associated with increased NO bioavailability and decreased oxidative stress; increased expression of HSP90 and; prevented the increase of ß-arrestin, Gai1,2, p-Src, ERK1/2 and p-ERK1/2 and osteopontin induced by ß-adrenergic overstimulation. These results suggest that the vascular effects induced by ISO in aorta are mediated by a MR activation / Mestrado / Fisiologia / Mestra em Biologia Funcional e Molecular

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