Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-07-17T11:42:56Z No. of bitstreams: 2 Dissertação - Paula Rodrigues Vitorino - 2016.pdf: 2307568 bytes, checksum: 8b0ba8c9e0ad9c9d3c15c47fd68109c9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-19T11:25:44Z (GMT) No. of bitstreams: 2 Dissertação - Paula Rodrigues Vitorino - 2016.pdf: 2307568 bytes, checksum: 8b0ba8c9e0ad9c9d3c15c47fd68109c9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-19T11:25:44Z (GMT). No. of bitstreams: 2 Dissertação - Paula Rodrigues Vitorino - 2016.pdf: 2307568 bytes, checksum: 8b0ba8c9e0ad9c9d3c15c47fd68109c9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-09-19 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Epilepsy is the most common chronic neurological disease in the world, characterized by paroxysmal, excessive and synchronous discharges of a neuronal population that leads to spontaneous and recurrent seizures. Sudden unexpected death in epilepsy (SUDEP) is responsible for 7.5% to 17% of deaths in epilepsy. Although the pathophysiological mechanisms are unknown, one possible explanation is that they are of cardiogenic origin. Some studies relate cardiac abnormalities with seizures, and these may be responsible for Suped, and as yet has no works that have investigated the control of coronary flow of patients or in experimental models of epilepsy, and as coronary heart disease listed as one of the main causes of sudden death in the world population, assess coronary flow in experimental epilepsy model becomes important for the understanding of SUDEP. So this study aims to evaluate the coronary reactivity, ventricular function and cardiac tissue of rats submitted to the pilocarpine model of epilepsy. The animals were separated into two groups: control (n = 8) and epilepsy (n = 8). It was administered 350 mg/kg of pilocarpine (i.p) preceded by 1mg/kg methylscopolamine (s.c) in both groups, animals that entered in status epilepticus received diazepam 10 mg/kg (i.p) after 3 hours to block it. After that, the animals were placed in a room for video monitoring (24 h/day) until complete two months of epilepsy (epilepsy group). Rats that received pilocarpine and did not develop status epilepticus comprised the control group, being housed in the same animal environment that epilepsy group. At two months of chronic epilepsy rats were sacrificed and the heart dissected to the Langendorff preparation (constant flow), after a 35 minutes of stabilization in a Krebs - Ringer solution bradykinin (BK) was administered (10ˉ⁸, 10ˉ⁷, 10ˉ⁶ and 10ˉ⁵M) in bolus and after of washout was treated with sodium nitroprusside in different concentrations (10ˉ⁶, 10ˉ⁵, 10ˉ⁴ and 10ˉ³M) also bolus. They were found in animals with epilepsy a significant reduction in coronary relaxation by BK infusion at a concentration 10ˉ⁵M. It was observed that rats with epilepsy have increased perivascular collagen, larger cardiomyocytes, and more coronary arteries, with no change of nitric oxide synthase endoletial (eNOS), superoxide dismutase (SOD) and catalase expression. Thus, our results show reduction of coronary relaxation induced by bradykinin which leads us to believe in loss of endothelial function of these animals, since, we did not observe differences in relaxation induced by sodium nitroprusside, despite the perivascular fibrosis of epileptic rats. / A epilepsia uma das doenças neurológicas crônicas graves mais comuns, caracterizada por descargas paroxísticas, excessivas e sincrônicas de uma população neuronal que leva a crises espontâneas e recorrentes. A morte súbita e inesperada nas epilepsias (SUDEP) é responsável por 7,5% a 17% das mortes em epilepsia. Embora os mecanismos fisiopatológicos sejam desconhecidos, uma possível explicação é que sejam de origem cardiogênica. Alguns trabalhos relacionam alterações cardíacas com as crises, podendo estas serem responsáveis pela SUPED, e como ainda não tem trabalhos que tenham investigado o controle do fluxo coronariano de pacientes ou em modelos experimentais de epilepsia, e como as doenças coronarianas figuram como uma das principais causas de morte súbita na população mundial, avaliar o fluxo coronariano em modelo experimental de epilepsia torna-se importante para o entendimento da SUDEP. Assim este trabalho teve como objetivo avaliar a reatividade coronariana, função ventricular e o tecido cardíaco de ratos submetidos ao método de indução de epilepsia pelo modelo da pilocarpina. Os animais foram separados em dois grupos: Controle (n= 8) e Epilepsia (n= 8). Foi administrado 350 mg/Kg de pilocarpina (i.p.) precedidos por 1mg/Kg de metilescopolamina (s.c.) em ambos os grupos, os animais que entraram em estado de mal epiléptico receberam diazepam 10 mg/Kg (i.p.), após 3 horas em estado de mal epiléptico, para bloqueá-lo. Depois os animais foram acondicionados em uma sala para monitoramento por vídeo (24 h/dia) até completarem 2 meses de epilepsia, formando o grupo epilepsia. Os animais que não entraram estado de mal epiléptico após a indução do modelo compuseram o grupo controle, ficando alojados no mesmo ambiente dos animais do grupo epilepsia durante todo o período. Após a cronificação da epilepsia (2 meses após primeira crise) realizou-se a metodologia de coração isolado pelo sistema de Langendorff fluxo constante, e após um período de estabilização de cerca de 35 minutos perfundiu-se o coração com bradicinina (BK) (10ˉ⁸, 10ˉ⁷, 10ˉ⁶ e 10ˉ⁵M) em bolus e após lavagem perfundiu-se com nitroprussiato de sódio (NPS) (10ˉ⁶, 10ˉ⁵, 10ˉ⁴, e 10ˉ³M) também em bolus. O coração dos ratos com epilepsia apresentou uma redução significativa no relaxamento coronariano mediante infusão de BK na concentração 10ˉ⁵M. Além disso, observamos que os animais com epilepsia possuem colágeno perivascular aumentado, cardiomiócitos maiores, e maior número de coronárias, sem alteração da expressão de óxido nítrico sintase endoletial (eNOS), superóxido dismutase (SOD) e catalase. Assim, nossos resultados mostram que há uma redução do relaxamento coronariano induzido por bradicinina o que nos leva crer em prejuízo da função endotelial desses animais, uma vez que, embora com fibrose perivascular não houve alteração quando o relaxamento foi induzido pelo nitroprussiato de sódio.

Le surpoids et l'obésité, en constante augmentation à l'échelle mondiale à un rythme exponentiel, conduit au développement du syndrome métabolique et du diabète de type 2. Plusieurs études ont mis en évidence l'association entre l'excès de masse grasse, en particulier dans la région abdominale, et le développement des maladies cardiovasculaires. Une telle augmentation de masse grasse corporelle caractérise le vieillissement normal, qui est considéré per se comme un facteur de risque majeur pour les maladies cardiovasculaires. De plus, dans le monde industrialisé, l'incidence des maladies cardiovasculaires est encore plus élevée et fortement liée aux habitudes occidentales (régimes obésogènes, sédentarité) qui contribuent à l'accumulation de la graisse abdominale. L'objectif général de ce travail consiste à suivre les changements corporels qui surviennent entre la jeunesse et l'âge moyen où commence à survenir les complications cardio-vasculaires et à savoir comment l'obésité induite par l'alimentation peut modifier ces aspects. Dans un premier temps, nous avons montré que les coeurs des rats Wistar d'âge moyen sont caractérisés par une moindre restauration de l'activité mécanique cardiaque au cours de la réperfusion post-ischémique en raison de perturbations de la perfusion coronaire et d'une insuffisance de l'apport en oxygène. La présence d'un stress oxydant systémique suite à l'augmentation de la masse grasse survenant entre la jeunesse et l'âge adulte est également en cause. Une diminution progressive de la dilatation endothélium-dépendante des microvaisseaux coronaires est également observé avec le vieillissement, ce qui résulte d'une évolution différentielle du comportement fonctionnel des cellules endothéliales et musculaires lisses apparemment liée au métabolisme énergétique et au stress oxydant. L'obésité induite par un régime riche en graisse provoque un certain nombre de modifications corporelles, métaboliques et cardiovasculaires au cours de cette période du vieillissement. L'excès de masse grasse abdominale induit une augmentation du stress oxydant aux niveaux systémique, cytosolique et mitochondrial accompagné par des altérations biochimiques concernant le métabolisme du glucose et les niveaux plasmatiques de cholestérol et de triglycérides. L'obésité induite par une hyperphagie et la présence d'un diabète de type 2 chez les rats Zucker obèses diabétiques provoque également une insulino-résistance sévère. Ces deux modèles d'obésité sont caractérisés par une diminution de la fonction cardiaque ex vivo liée au métabolisme énergétique mitochondrial et au stress oxydant. En outre, ils sont tous les deux caractérisés par une adaptation des microvaisseaux coronaires dont la réactivité est augmentée dans le cas de régime riche en graisse et maintenue dans le cas du diabète. Ces adaptations sont dues à des mécanismes différents dans les deux modèles d'obésité. Elles permettent de mieux répondre aux exigences métaboliques élevées liées à l'obésité. En conclusion, notre travail montre que les caractéristiques corporelles et métaboliques, le métabolisme énergétique mitochondrial, la fonction cardiaque et la réactivité coronaire sont modifiés lors du vieillissement dans les conditions normales ou obésogènes. Ces résultats encouragent la recherche ultérieure des mécanismes mis en jeu. Les interventions visant à réduire la masse grasse, qu'elle soit spontanément accrue par l'âge ou qu'elle résulte du régime alimentaire, seraient d'un grand intérêt pour retarder les complications cardiovasculaires. / The prevalence of overweight and obesity is increasing worldwide at an alarming rate leading to the development of metabolic syndrome and diabetes mellitus. Previous studies have highlightened the association between fat accumulation, especially in the abdominal area, and the development of cardiovascular diseases. An increase in body and fat mass characterizes normal aging, which is considered per se the major risk factor for cardiovascular diseases. In the industrialized societies, the incidence of cardiovascular diseases occurring with age is even more increased due to the Western-world lifestyle habits (e.g. obesogenic diets, sedentariness) that contribute to excess fat accumulation. Accordingly, the overall goal of this work was to understand how body changes occurring from youth to middle age were related to middle age cardiovascular complications and how diet-induced obesity altered these aspects. Initially, we demonstrated that in normal aging middle-aged hearts of Wistar rats were characterized by lower restoration of the cardiac mechanical activity during reperfusion ex vivo due to impaired recovery of the coronary flow and insufficient oxygen supply. This was also related to the presence of increased systemic oxidative stress following the increase in fat mass that occurred from youth to young adulthood. A progressive decline in the endothelium-dependent dilatation of the coronary microvasculature also occurred with aging, which was due to different functional behaviours of the endothelial and smooth muscular cells, which appeared to be related to the energy metabolism and oxidative stress. High-fat diet-induced obesity triggered a number of alterations in the body, metabolic and cardiovascular characteristics of the animals during this aging period. The excess abdominal fat accumulation provoked the increase of oxidative stress at the systemic, cytosolic and mitochondrial levels accompanied by biochemical alterations in the glucose and lipid metabolisms such as hypercholesterolemia and hypertriglyceridemia. The hyperphagia-induced obesity and the related type 2 diabetes in the Zucker diabetic fatty rats provoked also severe insulin resistance. Both models of diet-induced obesity were characterized by decreased ex vivo cardiac function related to mitochondrial energy metabolism and oxidative stress. Furthermore, they were both characterized by an adaptation of the coronary microvasculature whose reactivity was enhanced in the first case and maintained in the second, in order to meet the elevated metabolic demands of the hearts due to obesity. These adaptations were due to different mechanisms in these two models of obesity. In conclusion, our work revealed a temporal pattern of changes concerning the body and metabolic characteristics, mitochondrial energy metabolism, cardiac function and coronary microvascular reactivity that occur from youth to middle age either under normal or obesogenic-related conditions. These results encourage further research in order to explain the mechanisms related to these alterations. Interventions aiming at reducing the fat mass that increases with age or diet would be of great interest in an effort to delay the cardiovascular