Os efeitos do treinamento físico aeróbio sobre o sistema renina-angiotensina cardíaco (SRA) foram avaliados em camundongos com insuficiência cardíaca (IC) e em seus respectivos controles (WT). O treinamento físico foi conduzido em esteira rolante (8 semanas, 5 x/sem, 60 min por dia). A tolerância à realização de esforço físico, e análises estruturais e funcionais cardíacas foram avaliadas. Os camundongos apresentaram disfunção cardíaca e fibrose associadas ao aumento na expressão de angiotensina II cardíaca e ao aumento na atividade da enzima conversora de angiotensina cardíaca (ECA). O treinamento físico aeróbio reduziu os níveis de angiotensina II e de ECA cardíaca para os mesmos valores apresentados pelo grupo controle. Além disso, elevou a expressão da ECA2 cardíaca, preveniu a intolerância à realização de esforço físico e a disfunção cardíaca, com pouco impacto sobre o remodelamento cardíaco / The effects of aerobic exercise training on the cardiac renin-angiotensin system (RAS) was evaluated in mice with heart failure (HF) and control (WT). The exercise training was realized in a motor treadmill (8 weeks, 5d/wk, 60 min/day). The exercise tolerance, structural and function analysis were evaluated. Mice displayed cardiac dysfunction and fibrosis associated to increased in cardiac angiotensin II expression and angiotensin converting enzyme activity (ACE). The exercise training reduced cardiac angiotensin II and ACE levels to age-matched WT. In addition, increased the ACE2 expression, prevent the exercise intolerance and cardiac dysfunction, with little impact on cardiac remodeling

Diversos estudos observaram uma correlação entre doenças na idade adulta e o ambiente durante a vida fetal. O estudo realizado por Barker e colaboradores foi um dos primeiros a relatar a hipótese de um possível envolvimento do ambiente intra-uterino com o desenvolvimento de doenças cardiovasculares, mas os mecanismos responsáveis por esta associação ainda não são totalmente conhecidos. Estudos demonstraram uma associação entre baixo peso ao nascimento com resistência à insulina e intolerância à glicose na vida adulta. Recentemente, verificamos que o consumo de dieta hipossódica, conhecido modelo de resistência à insulina, durante a gestação e lactação está vinculado a menor sensibilidade à insulina na prole adulta. Visto que a presença de resistência à insulina durante a gestação leva a diversas alterações metabólicas na prole adulta, pode-se supor que a sobrecarga de sacarose, um modelo de resistência à insulina, durante a gestação e lactação influencie no desenvolvimento da prole. Assim, o objetivo do presente estudo foi verificar a repercussão da resistência à insulina, durante a gestação sobre a prole adulta. Para tanto, ratas Wistar foram alimentadas com dieta hipo (HO) ou normossódica (NR) suplementadas ou não com sacarose (NR+SAC - 20g/dL) ou maltodextrina (NR+MALTO - 20g/dL) desde a oitava semana de vida até o final da gestação e amamentação. Na prole resultante destes animais foi observado menor peso ao nascimento nos grupos HO, NR+SAC e NR+MALTO. Esta alteração resultou no desenvolvimento de maior insulinemia, pressão arterial e maior captação de glicose na prole de fêmeas das mães do grupo NR+SAC. Os machos apresentaram menor índice de adiposidade e maior expressão gênica renal dos componentes do sistema renina-angiotensina. Tais resultados nos permitem concluir que a sobrecarga de carboidratos durante a gestação e lactação está associada a alterações no peso ao nascimento e no metabolismo da insulina na idade adulta. É possível que a ativação do sistema renina-angiotensina materno induzido pela sobrecarga de carboidrato esteja associada a alterações deste mesmo sistema observado na prole adulta. / Many studies observed a correlation between diseases in adult subjects and the environment during the fetal life. Barker and coworkers hypothesized that there is a possible intrauterine enviroment association with cardiovascular diseases in adulthood. The mechanisms responsible for this association are still not very well known. Recently, we have verified that low-salt diet consumption, a well-known model of insulin resistance, during pregnancy and lactation is associated with a lower insulin sensitivity in the adult offspring. Since insulin resistance during pregnancy leads to many metabolic alterations in the adult offspring, we suppose that sucrose overload during pregnancy and lactation could influence the offspring development. The aim of this study was to verify the effects on adult offspring of insulin resistance during pregnancy and lactation. Female Wistar rats were fed low (LSD) and normal-salt diet (NSD) supplemented or not with sucrose (SUC - 20 g/dL) or maltodextrin (MALTO - 20 g/dL) until the end of pregnancy and lactation. Lower birth weight was observed in offspring of LSD, SUC and MALTO groups. Higher plasma insulin level, blood pressure and glucose uptake was detected in the adult SUC female offspring. SUC male offspring had lower adiposity index and higher gene expression of the renal renin-angiotensin components. These results show that carbohydrate overload during pregnancy and lactation is associated with alterations in birth weight and in insulin metabolism at adult life. It is possible that the maternal renin-angiotensin system activation by the carbohydrate overload is associated with alterations in the same system observed in the adult offspring.

Estudamos a amostra das ouropretanas com prevalência de hipertensão arterial de (52,7%). O objetivo foi descrever os fenótipos sistólico, diastólico e pressão de pulso e correlacionar as variantes genética da ECA e AGT. Os dados sugerem que a prevalência de hipertensão entre elas estão associadas a idade, classe social, escolaridade, hiperglicemia, circunferência da cintura abdominal, e perfil lipídico. O alelo T foi significante com glicemia {p < 0,02 (OR = 2,2)} e cor preta {p < 0,002 (OR = 2,7)} o alelo D com idade {p < 0,01 (OR = 2,2)} e HDL {p < 0,0007 (OR= 1,5)}. O genótipo DD com a idade {p < 0,03 (OR = 0,7)} e HDL {p < 0,008 (OR = 2,0)}. A influência das variantes genéticas da ECA e do AGT tiveram pouco efeito sobre os fenótipos de pressão arterial, mas influenciaram os níveis de colesterol HDL e a glicemia, respectivamente. / We studied the sample of women from Ouro Preto with a prevalence of arterial hypertension of (52,7%). The objective was to describe systolic, diastolic and pulse pressure phenotypes and correlate the ECA and AGT genetic variants. The data suggests that the prevalence of hypertension among them is related to age, social class, schooling, hyperglycemia, abdominal and lipidic profile. The T allele showed significance with glycemia {p < 0.02 (OR = 2.2) and color black {p < 0.002 (OR = 2.7)}. The D allele with age {p < 0.01 (OR = 2.2)} and HDL {p < 0.0007 (OR=1.5)}. The DD genotype with age {p < 0.03 (OR = 0.7)} and HDL {p<O.008 (OR = 2.0)}. Influence of the ECA and AGT genetic variants had little effect on arterial pressure phenotypes, but influenced the levels of HDL cholesterol and the hyperglycemia respectively.

O presente estudo avaliou aspectos relacionados ao contexto inflamatório na hipertrofia cardíaca induzida pelos hormônios tiroideanos (HT) e o possível envolvimento do sistema renina-angiotensina (SRA) nesse processo, utilizando análises in vivo e com enfoque maior na abordagem in vitro. Os resultados mostraram algumas alterações em citocinas circulantes e cardíacas de animais tratados com HT. Além disso, as expressões de S100A8 e MyD88 foram aumentadas no coração de ratos submetidos ao hipertiroidismo e em cardiomiócitos em cultura estimulados com HT. S100A8 e MyD88 mediaram a ativação do fator nuclear NF-&#954;B pelos HT, tendo papel crucial para o crescimento hipertrófico de cardiomiócitos tratados com HT. Por fim, a ação dos HT modulando a expressão de S100A8 e NF-&#954;B foi mediada pelo SRA. Estes dados contribuem com o entendimento das bases moleculares da ação dos HT e da relação deste com o SRA na hipertrofia cardíaca. / The present study evaluated inflammation related aspects in cardiac hypertrophy induced by thyroid hormones (TH) and the possible involvement of the renin-angiotensin system (RAS) in this process, by using in vivo and in vitro analysis. The results showed alterations in circulating and cardiac cytokines from TH treated animals. The expression of S100A8 and MyD88 were increased in the heart of hyperthyroid rats and in cultured cardiomyocytes stimulated with TH. S100A8 and MyD88 mediated the nuclear factor NF-&#954;B activation by TH and these factors presented crucial role to the hypertrophic growth of TH-treated cardiomyocytes. Finally, the action of TH on S100A8 and NF-&#954;B expression was mediated by RAS. These data contribute to the knowledge of molecular basis of TH action and the relationship between TH and RAS in cardiac hypertrophy.

Os experimentos indicam, como já demonstrado em estudos prévios do laboratório, que angiotensina II (Ang II) apresenta efeito estimulatório sobre a cinética de recuperação de pHi em células OKP. Tal estímulo não é acentuado pela super-expressão de AT1aR recombinante, ao contrário do que imaginávamos inicialmente. Acreditamos que, por conta da capacidade de amplificação de sinal característica dos receptores acoplados a proteína G, um aumento de expressão do receptor AT1aR em relação ao nível endógeno seja redundante para o fenômeno biológico estudado. Por outro lado, os resultados para o grupo com super-expressão de ATRAP corroboram nossa hipótese inicial, ao indicar uma atenuação do efeito de Ang II sobre a recuperação de pHi, em comparação aos demais grupos experimentais tratados com Ang II. Considerando que a recuperação de pHi em células OKP reflete essencialmente a atividade de troca Na+/H+ mediada pelo contra-transportador NHE3, podemos concluir que a regulação positiva de NHE3 via AT1aR/AngII é prejudicada pelo aumento de expressão da proteína ATRAP. / The experimental data suggests that, as shown in previous works from our laboratory, angiotensin II (Ang II) raises the pHi recovery rate in OKP cells. This upregulation is not enhanced by recombinant AT1aR overexpression, contrary to our initial hypothesis. We believe that, due to signal amplification mediated by G-protein coupled receptors, any increase in AT1aR would be redundant considering the biological phenomenon of interest. On the other hand, results from the ATRAP overexpression group supports our initial hypothesis, pointing an attenuated effect of Ang II over pHi recovery in relation to the remaining groups treated with Ang II. Considering that pHi recovery in OKP cells primarily reflects the Na+/H+ exchange activity mediated by NHE3 antiporter, we can conclude that NHE3 upregulation mediated by AT1aR/AngII is impaired by an increase in ATRAP protein expression.

A nefrotoxicidade induzida por contraste (NIC) é responsável por cerca de 11% de todas as causas de injúria renal aguda no ambiente hospitalar e tem sido atribuída exclusivamente aos contrastes iodados. Contudo, os contrastes à base de gadolínio recentemente estão sendo reportados como potenciais indutores de nefrotoxicidade em pacientes de alto risco. A fisiopatologia da NIC está relacionada à geração de hipóxia na medula renal vinculada à disfunção endotelial, e ao estresse oxidativo, alterações que têm sido fortemente associadas à deficiência de vitamina D (dVD), condição que encontra-se altamente prevalente na população atual, mesmo em países de clima tropical. O objetivo desse estudo foi testar a hipótese de que a dVD é um potencial fator de risco para NIC. Para isso, ratos Wistar foram mantidos em dieta padrão ou livre de vitamina D por 30 dias. A seguir, CI (diatrizoato 76%), Gd (gadoterato de meglumina) ou soro fisiológico 0,9% foram infundidos por via endovenosa. Seis grupos foram avaliados (n=12/grupo): Sham, CI, Gd, dVD30, dVD30+CI e dVD30+Gd. Após 48h da infusão dos contrastes, os animais foram submetidos ao experimento de clearance de Inulina, para estimar o ritmo de filtração glomerular (RFG), a análise da expressão proteica no tecido renal de angiotensinogênio (AGT), renina e da óxido nítrico sintase endotelial (eNOS), e ao exame histológico. O estado redox foi avaliado por meio da medida das espécies reativas ao ácido tiobarbitúrico (TBARS, marcador de peroxidação lipídica), e dos níveis de glutationa reduzida (GSH, antioxidante endógeno) sistêmico e renal. Comparado ao grupo Sham, os animais dVD30 apresentaram menores níveis séricos de 25(OH)D total (3,96±0,8 vs. 44,87±1,7 ng/mL, p < 0,001), níveis semelhantes de cálcio e fósforo plasmáticos e aumento da expressão renal de AGT e renina. O RFG foi similar nos grupos Sham, CI e Gd. Entretanto, o RFG foi significantemente menor nos grupos dVD30+CI e dVD30+Gd e esta redução esteve associada ao aumento no tecido renal da expressão de AGT e à redução da eNOS, combinado à acentuada elevação da razão TBARS/GSH no tecido renal. Apesar da alteração na função renal com a infusão dos contrastes, a morfologia renal permaneceu preservada. Foram feitos dois grupos adicionais (n=5/grupo) mantidos em dVD por 60 dias. Após administração dos contrastes, uma maior queda do RFG foi observada, sugerindo que uma dVD mais prolongada agrava ainda mais a queda do RFG. Coletivamente, nossos resultados indicam que a dVD é um potencial fator de risco para NIC iodado e de gadolínio em consequência do desequilíbrio intrarrenal de substâncias vasoativas por meio da ativação do sistema renina-angiotensina e do estresse oxidativo / Contrast-induced nephropathy (CIN) account for about 11% of all causes of acute kidney injury in hospitalized patients and has been attributed exclusively to iodinated contrast media. However, gadolinium-based contrast agents are reported recently as potential inducers of nephrotoxicity in high risk patients. Pathophysiology of CIN is related to hypoxia in the renal medulla associated with endothelial dysfunction and oxidative stress, changes that have been strongly linked to vitamin D deficiency (VDD), condition that is highly prevalent in the current population, even in tropical countries. This study tested the hypothesis that VDD is a predisposing factor for iodinated and gadolinium contrast media nephrotoxicity. To this end, male Wistar rats were fed standard or vitamin D-free diet for 30 days (VDD30). Then, IC (diatrizoate 76%), Gd (gadoterate meglumine) or saline were administered intravenously and six experimental groups were obtained: Sham, IC, Gd, VDD30, VDD30+IC and VDD30+Gd. Renal hemodynamics, redox status, histological and immunoblot analysis were evaluated 48h after contrast or vehicle infusion. Compared to Sham, VDD30 rats presented lower levels of total 25(OH)D (3.96 +- 0.8 vs. 44.87 ± 1.7 ng/mL, p < 0,001), similar plasma levels of calcium and phosphorus and higher renal renin and angiotensinogen expression. Inulin clearance-based estimated glomerular filtration rate (GFR) was not different among Sham, IC and Gd groups. However, GFR was significantly reduced in VDD30+IC and VDD30+Gd groups and this reduction was associated with higher renal angiotensinogen and lower eNOS abundance combined with higher kidney thiobarbituric acid reactive substances and lower glutathione levels. Conversely, worsening of renal function was not accompanied by abnormalities on kidney structure or increased infiltration of inflammatory cells. Rats on a VDD for 60 days displayed a greater fall in GFR after contrast administration, suggesting that the longer the period of VDD, the worst the impact of contrast media on renal function. Collectively, our findings suggest that VDD is a potential risk factor for contrast nephropathy due to imbalance in intrarenal vasoactive substances by renin-angiotensin system activation and oxidative stress

Introdução: Hipertrofia de ventrículo esquerdo (HVE) detectada pelo ecocardiograma é um preditor independente de morbidade e mortalidade em indivíduos hipertensos e na população em geral. Na população adulta existe uma modesta correlação entre a medida casual da pressão arterial (PA) e HVE . A HVE pode preceder a hipertensão arterial (HA) sustentada. Existem trabalhos que demonstram que indivíduos normotensos e com resposta exagerada da PA ao esforço tem alta probabilidade de desenvolvimento de HA sustentada no futuro, assim como alta prevalência de HVE. Há divergências no que diz respeito a participação do sistema neurohumoral na HVE nesse grupo especifíco de indivíduos, sendo que alguns dados da literatura apontam a hiperatividade simpática como fator desencadeador , no entanto, parece haver uma correlação independente e significativa entre a relação aldosterona/renina e aumento da PA sistólica durante o exercício . Nosso trabalho teve como objetivo avaliar a influência neurohumoral nesses indivíduos comparando drogas que bloqueiam o sistema nervoso simpático (SNS) com drogas que atuam bloqueando o sistema renina angiotensina (SRA). Métodos e Resultados: Durante 12 meses foram avaliados 195 indivíduos normotensos, hiperreatores ao teste de esforço e com HVE que foram submetidos a tratamento com exercício físico supervisionado, rilmenidina 1 mg/dia, atenolol 50 mg/dia, enalapril 10 mg/dia ou losartan 50 mg/dia. Mudanças no índice de massa de ventrículo esquerdo (IMVE) medida através do ecocardiograma foi o desfecho primário. Mudanças na pressão sistólica de repouso e no esforço máximo também foram avaliadas. Enalapril reduziu significativamente o IMVE com relação ao basal (137,0±8,8 para 107,1±9,4 g/m2; n=36) similar ao losartan (136,0±8,7 para 107,7±10,6 g/m2; n=42); P>0,05, porém ambas foram mais eficazes de que exercício físico (136,7±10,1 para 132,8±10,4 g/m2; n=39), rilmenidina (135,7±10,2 para 129,0±9,4 g/m2;n=38) e atenolol (134,0±8,9 para 125,2±9,6 g/m2; n=40); p<0,05. Todos os tratamentos reduziram a pressão arterial sistólica no repouso e esforço máximo quando comparados ao basal, porém a redução da pressão sistólica de repouso foi mais acentuada com atenolol (135±5 para 123±6 mmHg), enalapril (134±5 para 122±7 mmHg) e losartan (133±5 para 123±6 mmHg) do que com exercício físico (132±5 para 128±7 mmHg) e rilmenidina (135±4 para 129±7 mmHg); P<0,05. Não houve diferença significativa na redução da PAS no esforço máximo entre os grupos atenolol (225±5 para 183±10 mmHg), enalapril (225±5 para 182±9 mmHg) e losartan (225±3 para 184±10 mmHg); P>0,05, sendo a redução nesses grupos superior a redução nos grupos exercício físico (225±4 para 193±11mmHg) e rilmenidina (226±6 para 191±12 mmHg); P<0,05. Conclusões: As drogas que bloqueiam o SRA foram mais eficazes na redução da HVE em pacientes hiperreatores de que exercício físico e drogas que bloqueiam o SNS e essa redução foi independente da redução dos níveis de PAS no repouso e esforço máximo / Introduction: Left ventricular hypertrophy (LVH) as detected by echocardiogram is an independent predictor of morbidity and mortality in individuals having high blood pressure and in population in general. In adult population there is a modest correlation between casual measurement of blood pressure (BP) and LVH. LVH may precede sustained arterial hypertension (AH). Some papers demonstrate that normotensive individuals with exaggerated BP response to effort are highly likely to develop sustained AH later, as well as high prevalence of LVH. There are divergences concerning the role neurohumoral system plays in LVH within this specific group of individuals, with some data in literature pointing out to sympathetic hyperactivity as a triggering factor. Nevertheless, there seems to be an independent and significant correlation between the aldosteron/renin ratio and an increase in systolic BP during exercise. Our paper aims at evaluating neurohumoral influence over these individuals by comparing drugs that block the sympathetic nervous system (SNS) to drugs that block the renin angiotensin system (RAS). Methods and Results: Over a period of 12 months, 195 individuals (normotensive, with exaggerated blood pressure response to treadmill exercise test and with LVH) were evaluated. These individuals underwent a treatment with supervised physical training, rilmenidine 1 mg/day, atenolol 50 mg/day, enalpril 10 mg/day or losartan 50 mg/day. Changes in left ventricular mass index (LVMI), measured by means of echocardiogram were the primary endpoint. Changes in systolic pressure at rest and at peak effort were also evaluated. Enalapril significantly brought LVMI down in relation to basal (137.0±8.8 to 107.1±9.4 g/m2 ; n=36) similarly to losartan (136.0±8.7 to 107.7± 10.6 g/m2; n=42); P>0.05. However, both were more efficient than physical training (136.7±10.1 to 132.8± 10.4 g/m2; n=39), rilmenidine (135.7±10.2 to 129.0± 9.4 g/m2;n=38) and atenolol (134.0± 8.9 to 125.2±9.6 g/m2; n=40); p<0.05. All treatments brought down systolic blood pressure (SBP) at rest and at peak effort when compared to basal, but systolic pressure reduction at rest was more pronounced with com atenolol (135±5 to 123±6 mmHg), enalapril (134±5 to 122±7 mmHg) and losartan (133±5 to 123±6 mmHg) than with physical training (132±5 to 128±7 mmHg) and rilmenidine (135±4 to 129±7 mmHg); P<0.05. There was no significant difference in SBP reduction at peak effort in groups with atenolol (225±5 to 183±10 mmHg), enalapril (225±5 to 182±9 mmHg) and losartan (225±3 to 184±10 mmHg); P>0.05. In such groups, reduction was greater than in groups with physical training (225±4 to 193±11mmHg) and rilmenidine (226±6 to 191±12 mmHg); P<0.05. Conclusion: Drugs that block the renin angiotensin system (RAS) were more efficient in bringing LVH down in patients having high blood pressure than physical training and drugs that block the sympathetic nervous system (SNS) and such reduction took place regardless of SBP level reduction at rest and at peak effort

Evidências sobre a presença do sistema renina-angiotensina (SRA) na medula óssea e a possível participação da enzima conversora de angiotensina-I (ECA) na regulação hematopoética tem despertado o interesse da comunidade científica. Como a ECA também é um componente chave do sistema calicreína-cininas (SCC), é possível que elementos deste sistema, possam estar envolvidos no controle hematopoético. Assim, avaliamos a participação da ECA na regulação hematopoética de animais não modificados (WT) e nocautes dos receptores B1 de cininas (KOB1). Para isso, utilizamos técnicas de cultura de células de medula óssea, a saber: os ensaios clonogênicos em soft-ágar para granulócitos e macrófagos (CFU-GM) e o sistema de cultura líquida de longa duração (CLLD). Os resultados mostraram a presença da ECA em células das CLLD e indicaram a participação da enzima na proliferação de progenitores hematopoéticos possivelmente através do controle dos níveis de AcSDKP, pois o tratamento com o tetrapeptídeo e com captopril, reduziu significativamente o número CFU-GM in vitro e in vivo. Quando adicionado às CLLD, o AcSDKP foi capaz de aumentar significativamente a expressão do mRNA da ECA, sugerindo que seus níveis possam controlar a expressão gênica desta enzima. Em relação aos animais KOB1, os resultados mostraram maior atividade da ECA, acompanhado de aumento não significativo da expressão gênica e protéica da enzima. O tratamento das CLLD de animais WT com agonistas de receptores de cininas, não alterou a expressão gênica e a atividade da ECA. Assim, nossos dados sugerem que a ECA participa da regulação hematopoética neste modelo. No entanto, novos estudos serão necessários para a elucidação dos mecanismos envolvidos na expressão e/ou controle da atividade da ECA pelos receptores de cininas. / Evidences on the presence of the renin angiotensin system in the bone marrow and the possible participation of the angiotensin-I converting enzyme (ACE) in the hematopoietic regulation have aroused interest of the scientific community. As the ACE also is a common element of the kallikrein-kinin system (KKS), it is possible that elements of KKS, can be involved in the hematopoietic control. Thus, we evaluated the participation of the ACE on the hematopoietic regulation of wild-type (WT) and kinin receptor B1 knockout mice (KOB1). For this, we use techniques of bone marrow cell culture, to know the clonogenic assays for granulocyte-macrophage (GM-CFU) and the long term bone marrow cultures (LTBMC). The results shown the presence of the ACE in cells from LTBMC and its possible participation on hematopoietic proliferation through the control of AcSDKP levels, therefore the treatment with AcSDKP and captopril, decreased significantly the GM-CFU number in vitro and in vivo. When added to the LTBMC, the AcSDKP increase significantly the expression of ACE mRNA, suggesting that its levels could control the gene expression of this enzyme. In relation to KOB1 mice, the results shown increase of the ACE activity and not significant increase of the gene and protein expression of the enzyme. The treatment of the LTBMC of WT mice with kinins receptors agonists, did not modify the gene expression and the ACE activity. Thus, our data suggesting that ACE participate of the hematopoietic regulation in this model. However, new studies will be necessary to understand the involved mechanisms in the expression and/or control of ACE activity by kinins receptors.

O córtex pré-límbico (PL) é uma importante área límbica envolvida em vários processos funcionais correlatos ao estresse, tais como respostas cardiovasculares, hormonais e comportamentais. O modelo de estresse de restrição (ER) foi padronizado na literatura como uma situação aversiva capaz de promover aumento da pressão arterial e frequência cardíaca, queda da temperatura cutânea e estimulação do eixo hipotálamo-pituitária-adrenal (HPA). Trabalhos da literatura evidenciaram que ratos submetidos ao ER apresentavam aumento da atividade neuronial no PL, sugerindo que essa estrutura module respostas ao ER. Assim, a inibição temporária de sinapses no PL potencializou a resposta taquicárdica induzida pelo ER, sem alterar a resposta pressora. Além do controle cardiovascular, outros trabalhos demonstraram que o PL também participa do controle hormonal durante o ER. O ER agudo também está envolvido com a produção de espécies reativas de oxigênio (EROs), fator que pode estar envolvido nas alterações a longo prazo observadas após exposição a uma situação aversiva. O sistema renina angiotensina (SRA) central modula respostas cardiovasculares, inclusive aquelas induzidas por situações aversivas, além de ter um papel reconhecido na produção de EROs. Além disso, foi demonstrado que o PL possui SRA funcional com presença dos peptídeos a ele relacionados. Baseado nos fatos mencionados acima, a hipótese do presente projeto é que a neurotransmissão angiotensinérgica do PL está envolvida na modulação de respostas autonômicas (aumento de pressão arterial e frequência cardíaca, e queda da temperatura cutânea) e hormonal (aumento plasmático de corticosterona) evocadas pelo ER, e que essa via envolveria a formação de EROs. A microinjeção do inibidor da enzima conversora de angiotensina (ECA) lisinopril no PL, nas doses de 0,5 e 1nmol/100nL, reduziu a resposta pressora, sendo a dose de 1nmol/100nL de lisinopril também capaz de reduzir a resposta taquicárdica induzida pelo ER; porém nenhuma dose utilizada ocasionou mudanças na queda da temperatura cutânea evocada pelo ER. O pré-tratamento do PL com o antagonista de receptores do subtipo AT1 candesartan reduziu o efeito pressor induzido pelo ER, porém não alterou a resposta taquicárdica e queda da temperatura cutânea associadas ao ER. Por sua vez, o pré-tratamento com o antagonista de receptores do subtipo AT2, PD123177, reduziu a resposta taquicárdica sem alterar a resposta pressora e a queda da temperatura cutânea evocadas pelo ER. Em adição, o estresse de restrição agudo e os pré-tratamentos realizados não foram capazes de alterar a atividade da enzima NADPH oxidase no PL. Em conclusão, os presentes resultados sugerem a participação do SRA na modulação da resposta cardiovascular ao ER, através da ativação de receptores AT1, e AT2 do PL, afetando respectivamente, o componente vascular e o cardíaco da resposta autonômica causada pelo ER. Além disso, os resultados da atividade da enzima NADPH oxidase no PL sugerem que o ER agudo, os receptores AT1, AT2 e a ECA não modulam o status oxidativo local. / The prelimbic cortex is an important limbic structure involved in several stressrelated functional processes, such as cardiovascular, hormonal and behavior responses. Restraint stress (RS) was standardized in literature as an aversive situation able to promote blood pressure and heart rate increases, reduction in tail temperature and stimulation of the hypothalamic-pituitary-adrenal axis (HPA). Previous studies demonstrated that rats submitted to RS exhibited increased neuronal activity in the PL, suggesting that this structure modulates RS-evoked responses. Temporary, synaptic temporary inhibition in the PL markedly increased the RS-evoked tachycardiac response, without affecting the pressor one. Beyond cardiovascular control, other studies demonstrated that PL also participates in hormonal control during RS. Acute RS is also involved in the production of reactive oxygen species (ROS), which could be involved in long- term changes observed after exposure to an aversive situation. The central renin-angiotensin system (RAS) modulates cardiovascular responses, including those induced by aversive situations. In addition, this system has a well-known role in ROS production. Furthermore, the presence of angiotensinergic peptides in PL has also been demonstrated, suggesting the existence of a functional RAS in this structure. Based on the facts mentioned above, the hypothesis of the present study was that the angiotensinergic neurotransmission in PL is involved in the modulation of autonomic responses (blood pressure and heart rate increase, and reduction in tail temperature) evoked by RS, and this pathway would involve ROS formation. Microinjection of lisinopril (0.5 and 1nmol/100nL), an inhibitor of angiotensinconverting enzyme (ACE), into PL reduced the pressor response, and the dose 1nmol/nL was also able to reduce the tachycardiac response induced by RS; however, none of doses changed the reduction in tail temperature evoked by RS. PL treatment with candesartan, an AT1 receptors antagonist, reduced the RS-evoked pressor response, but did not affect the RS-evoked tachycardiac response and reduction in tail temperature. In addition, pretreatment with PD123177, an AT2 receptors antagonist, reduced the RS-evoked tachycardiac response, without affecting the pressor response or the RS-evoked reduction in tail temperature. In addition, neither acute RS or local treatments affected NADPH oxidase activity in the PL. In conclusion, the present results suggests the involvement of the central RAS in the modulation of the cardiovascular responses caused by RS, through the activation of both AT1 and AT2 receptors in the PL. The PL AT1 receptors modulating the vascular, and the AT2 modulating the cardiac component of RS-evoked autonomic response. Furthermore, our study suggests that neither acute RS or local AT1, AT2 and ACE affect oxidative status in the PL.

研究背景和目的 / 高血壓和糖尿病是人群中常見的疾病，兩者常共同存在，其共存的病理生理機制非常複雜，其中腎素血管景張素系統功能紊亂起重要作用。多個研究表明血管緊張素轉化晦抑制劑和血管緊張素II 1 型受體阻滯劑通過調節不同基因的表達，發揮其保護心血管和腎臟功能的效用。然而，目前仍缺乏遠兩類藥物影響全基因表達譜的全面調查。因此，本研究應用全基因表達譜晶片技術，檢測分析了高血壓和糖尿病並發的病人在服用安慰劑、雷米普利(ramipril)和替米沙坦(telmisartan)後的全基因表達譜的變化，從而全面評估了血管緊張素轉化臨抑制劑和血管繁張素II 1 型受體阻滯劑對相關基因的轉錄調控作用。 / 方法 / 11 名患有高血壓和糖尿病的病人(男性5 名)在服用安慰劑最少2 星期后，以隨機吹序接受為期各6 星期的雷米普利和替米沙坦治療，並分別在安慰劑期和2 個藥物治療期結束后提取心A 進行全基因表達譜分析。 / 結果 / 與服用安慰劑時的全基因表達譜相比，雷米普利治療后有267 個基因的表達降低， 99 個基因的表達增強。表達差異幅度為-2.0 至1.3 (P < 0.05) 。表達下降的基因主要與血管平滑肌收縮、炎症反應和氧化壓力相關。表達增強的基因主要與心血管炎症反應負調節相關。基因共表達網絡分析表明， 2 個共表達基因組與雷米普利的降血壓作用相闕， 3 個共表達基因組與肥胖相關。 / 與服用安慰劑時的全基因表達譜相比， 替米拉)、坦治療后有55 個基因表達降低， 158 個基因的表達增強。表達差異幅度為-1. 9 至1.3 (P < 0.05) 。表達增強的基因主要與脂質代謝、糖代謝和抗炎症因子作用相關。基因共表達網絡分析表明， 2 個共表達基因組與替米沙坦對24 小時舒張壓負荷量的作用相關， 2 個共表達基因組則與總膽固醇， 低密度脂蛋白膽固醇和C 反應蛋白相關。 / 結論 / 本論文描述了高血壓和2 型糖尿病病患全基因組表達的總體模式及經藥物治療後表達譜的相應改變， 為今後進一步研究腎素血管緊張素系統抑制劑和高血壓、糖尿病發展進程的相互作用提供了方向。 / Background and aim: Pathophysiological mechanisms underpinning the coexistence of hypertension and type 2 diabetes are complex systemic responses involving dysregulation of the renin-angiotensin system (RAS). We conducted this study to investigate the genome wide gene expression changes in patients with both hypertension and diabetes at three treatment stages, including placebo, ramipril and telmisartan. This study aimed to obtain a panoramic view of interactions between gene transcription and antihypertensive therapy by RAS inhibition. / Methods: 11 diabetic patients (S men) with hypertension were treated with placebo for at least 2 weeks followed by 6 weeks randomised crossover treatment with ramipril Smg daily and telmisartan 40mg daily, respectively. Total RNA were extracted from leukocytes at the end of placebo and each treatment period, and were hybridized to the whole transcript microarray. The limma package for R was used to identify differentially expressed genes between placebo and the 2 active treatments. The weighted gene coexpression network analysis (WGCNA) was applied to identify groups of genes (modules) highly correlated to a common biological function in pathogenesis and progression of hypertension and diabetes. / Results: There were 267 genes down-regulated and 99 genes up-regulated with ramipril. Fold changes of gene expression were ranged from -2.0 to 1.3 (P < 0.05). The down-regulated genes were involved in vascular signalling pathways responsible for vascular smooth muscle contraction, inflammation and oxidative stress. The up-regulated genes were associated with negative regulation of cardiovascular inflammation. The WGCNA identified 17 coexpression gene modules related to ramipril. The midnight blue (57 genes, r < -0.44, P < 0.05) and magenta (190 genes, r < -0.44, P < 0.05) modules were significantly correlated to blood pressure differences between placebo and ramipril. / There were 55 genes down-regulated and 158 genes up-regulated with telmisartan. Fold changes of gene expression were ranged from -1.9 to 1.3 (P < 0.05). The down-regulated genes were mainly associated with cardiovascular inflammation and oxidative stress. The up-regulated genes were associated with lipid and glucose metabolism and anti-inflammatory actions. The WGCNA identified 8 coexpression gene modules related to telmisartan. The black (56 genes, r = 0.46, P = 0.03) and turquoise (1340 genes, r = -0.48, P = 0.02) modules were correlated with diastolic blood pressure load. The blue (1027 genes) module was enriched with genes correlated with total cholesterol (r = - 0.52, P = 0.01), LDL-C (r = - 0.58, P = 0.004), and hsCRP (r = -0.57, P = 0.006). The green module (272 genes) was significantly correlated with LDL-C (r = - 0.44, P = 0.04) and hsCRP (r = - 0.59, P = 0.004). / Conclusion: Genome wide gene expression profiling in this study describes the general pattern and treatment responses in patients with hypertension and type 2 diabetes, which suggests future directions for further investigations on the interaction between actions of the RAS blockers and disease progression. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Deng, Hanbing. / "December 2011." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 198-256). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Declaration --- p.i / Publications --- p.ii / Abstract --- p.iv / 論文摘要 --- p.vi / Acknowledgements --- p.viii / Table of Contents --- p.x / List of tables --- p.xiv / List of figures --- p.xv / List of appendices --- p.xvii / List of abbreviations --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Epidemiology --- p.6 / Chapter 1.2.1 --- Epidemiology of hypertension --- p.9 / Chapter 1.2.2 --- Epidemiology of type 2 diabetes --- p.10 / Chapter 1.3 --- Aetiology --- p.13 / Chapter 1.3.1 --- Ageing --- p.13 / Chapter 1.3.1.1 --- Age-induced artery stiffness --- p.14 / Chapter 1.3.1.2 --- Age-related endothelial dysfunction --- p.14 / Chapter 1.3.2 --- The renin-angiotensin system (RAS) --- p.16 / Chapter 1.3.2.1 --- The local RAS --- p.20 / Chapter 1.3.2.2 --- The RAS and insulin resistance --- p.22 / Chapter 1.3.2.3 --- The RAS and inflammation --- p.26 / Chapter 1.3.2.4 --- The RAS and oxidative stress --- p.28 / Chapter 1.3.3 --- Obesity --- p.31 / Chapter 1.3.3.1 --- Obesity and renin-angiotensin system (RAS) --- p.33 / Chapter 1.3.3.2 --- Obesity and insulin resistance --- p.36 / Chapter 1.3.3.3 --- Obesity and oxidative stress --- p.38 / Chapter 1.3.3.4 --- Obesity and sympathetic nervous system (SNS) --- p.38 / Chapter 1.4 --- Pharmacogenomics of antihypertensive therapy --- p.39 / Chapter 1.4.1 --- Angiotensin-converting enzyme inhibitors (ACEIs) --- p.41 / Chapter 1.4.2 --- Angiotensin II type 1 receptor blockers (ARBs) --- p.43 / Chapter Chapter 2 --- Aim --- p.59 / Chapter Chapter 3 --- Methods --- p.60 / Chapter 3.1 --- Subjects --- p.60 / Chapter 3.1.1 --- Subject recruitment protocol --- p.60 / Chapter 3.1.2 --- Definition of type 2 diabetes --- p.62 / Chapter 3.1.3 --- Definition of obesity --- p.62 / Chapter 3.1.4 --- Definition of dyslipidaemia --- p.63 / Chapter 3.2 --- Study design and procedure --- p.64 / Chapter 3.2.1 --- Blood pressure assessments --- p.65 / Chapter 3.2.2 --- Anthropometric measurements --- p.68 / Chapter 3.2.3 --- Medical history, life style and side effect evaluation --- p.68 / Chapter 3.2.4 --- RNA isolation --- p.68 / Chapter 3.2.5 --- RNA quality assessment --- p.70 / Chapter 3.2.6 --- Oligonucleotide microarrays --- p.71 / Chapter 3.2.7 --- DNA extraction --- p.75 / Chapter 3.2.8 --- Biomedical measurements --- p.76 / Chapter 3.2.8.1 --- Glycosylated haemoglobin Alc (HbA₁c) --- p.77 / Chapter 3.2.8.2 --- Fasting plasma glucose (FP G) --- p.77 / Chapter 3.2.8.3 --- Fasting insulin --- p.77 / Chapter 3.2.8.4 --- Plasma urate --- p.77 / Chapter 3.2.8.5 --- High sensitive C-reactive protein (hsCRP) --- p.78 / Chapter 3.2.8.6 --- Fasting plasma triglycerides (TG) --- p.78 / Chapter 3.2.8.7 --- Fasting plasma cholesterols --- p.78 / Chapter 3.2.8.8 --- Renal and liver functions --- p.78 / Chapter 3.2.8.9 --- Urinary parameters --- p.79 / Chapter 3.3 --- Statistical Analysis --- p.79 / Chapter 3.3.1 --- Statistical analysis of clinical and biomedical data --- p.79 / Chapter 3.3.2 --- Analysis of microarray data --- p.80 / Chapter 3.3.2.1 --- Raw data assessment --- p.80 / Chapter 3.3.2.2 --- Data normalisation --- p.92 / Chapter 3.3.2.3 --- Data filtering --- p.96 / Chapter 3.3.2.4 --- Linear models for assessment of differential expression --- p.96 / Chapter 3.3.2.5 --- Weighted gene coexpression network analysis --- p.101 / Chapter 3.3.2.6 --- Network visualisation and gene ontology analysis --- p.102 / Chapter 3.3.3 --- Sample size calculation --- p.103 / Chapter Chapter 4 --- Results --- p.104 / Chapter 4.1 --- Demographic and biomedical characteristics at baseline --- p.104 / Chapter 4.1.1 --- Hypertension and diabetes status at baseline --- p.108 / Chapter 4.1.2 --- Prevalence of dyslipidaemia --- p.108 / Chapter 4.1.3 --- Prevalence of obesity --- p.109 / Chapter 4.1.4 --- Prevalence of metabolic syndrome --- p.109 / Chapter 4.1.5 --- Inflammation markers --- p.110 / Chapter 4.2 --- Blood pressure response to the RAS blockers --- p.110 / Chapter 4.2.1 --- Clinic blood pressure --- p.110 / Chapter 4.2.2 --- 24-hour ambulatory blood pressure --- p.112 / Chapter 4.3 --- Biomedical characteristics --- p.118 / Chapter 4.4 --- Compliance, side effects and adverse events --- p.120 / Chapter 4.5 --- Gene expression differences between treatments --- p.121 / Chapter 4.5.1 --- Gene expression differences between placebo and ramipril --- p.121 / Chapter 4.5.1.1 --- Expression changes in genes related to regulation of transcription with ramipril --- p.122 / Chapter 4.5.1.2 --- Expression changes with ramipril in genes related to molecular mechanism of cardiovascular changes in hypertension --- p.125 / Chapter 4.5.1.3 --- Expression changes in genes related to blood pressure with ramipril --- p.128 / Chapter 4.5.1.4 --- Expression changes in genes related to fatty acid metabolism with ramipril --- p.130 / Chapter 4.5.1.5 --- Expression changes in genes related to inflammation with ramipril --- p.130 / Chapter 4.5.1.6 --- Expression changes in genes related to oxidative stress with ramipril --- p.133 / Chapter 4.5.1.7 --- Power estimation --- p.133 / Chapter 4.5.2 --- Gene expression differences between placebo and telmisartan --- p.135 / Chapter 4.5.2.1 --- Changes in regulation oftranscription with telmisartan --- p.137 / Chapter 4.5.2.2 --- Expression changes in genes related to glucose metabolism with telmisartan --- p.141 / Chapter 4.5.2.3 --- Expression changes in genes related to lipid metabolism with telmisartan --- p.143 / Chapter 4.5.2.4 --- Expression changes in genes related to inflammation with telmisartan --- p.143 / Chapter 4.5.2.5 --- Power estimation --- p.145 / Chapter 4.5.3 --- WGCNA for comparison between placebo and ramipriI --- p.147 / Chapter 4.5.3.1 --- Midnight blue module and clinical responses to ramipril --- p.152 / Chapter 4.5.3.2 --- Magenta module and blood pressure responses to ramipril --- p.154 / Chapter 4.5.3.3 --- Yellow module and clinical responses to ramipril --- p.158 / Chapter 4.5.3.4 --- Red module and clinical responses to ramipril --- p.161 / Chapter 4.5.3.5 --- Salmon module and clinical responses to ramipril --- p.163 / Chapter 4.5.4 --- WGCNA for comparison between placebo and telmisaItan --- p.168 / Chapter 4.5.4.1 --- Diastolic blood pressure load and gene coexpression modules --- p.168 / Chapter 4.5.4.2 --- Lipids, hsCRP and gene coexpression modules --- p.172 / Chapter Chapter 5 --- Discussion --- p.176 / Chapter 5.1 --- Gene expression changes related to ramipril --- p.177 / Chapter 5.1.1 --- Gene expression changes and blood pressure reduction by ramipri1 --- p.177 / Chapter 5.1.2 --- Gene expression changes and vascular protection by ramipri1 --- p.181 / Chapter 5.1.3 --- Obesity and gene expression changes by ramipril --- p.183 / Chapter 5.2 --- Gene expression changes related to telmisartan --- p.185 / Chapter 5.2.1 --- Blood pressure and coexpressed gene modules with telmisartan --- p.185 / Chapter 5.2.2 --- Lipid metabolism and gene expression changes by telmisartan --- p.187 / Chapter 5.2.3 --- Glucose metabolism and gene expression changes by telmisartan --- p.189 / Chapter 5.2.4 --- hsCRP and gene expression changes by telmisartan --- p.190 / Chapter 5.3 --- Limitations of this study and future directions of research --- p.191 / Chapter Chapter 6 --- Conclusion --- p.194 / References --- p.198 / Appendices --- p.257