Heart disease is the leading cause of death in women in the United States. Premenopausal women appear to have better cardiac function and lower risk of heart disease compared to male postmenopausal female counterparts. Ovarian hormone loss influences blood pressure homeostasis and causes systemic inflammation, which may result in chronic stress on the heart. Two key physiological changes in cardiac dysfunction are reemergence of the fetal gene pattern and myocardial remodeling. Physical activity has been linked to improved cardiac function. The purpose of this study was to investigate the effects of ovariectomy on early markers of cardiac dysfunction and fibrosis and to determine if voluntary physical activity alters expression patterns in ovariectomized mice. We investigated the effects of ovariectomy and exercise on cardiac expression of fetal genes and markers and mediators of fibrosis in two cohorts of 8-10 week old female mice. Ovariectomized mice had greater expression of cardiac fetal genes and real time-PCR (RT-PCR) results indicated activation of the fibrosis pathway. Exercise was able to influence the expression of some markers of cardiac dysfunction. We concluded that ovarian hormone loss and associated physiological changes such as increased adiposity and systemic inflammation trigger early changes in cardiac gene expression that precede overt cardiac dysfunction.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Menopausal symptoms, primarily hot flashes, are a pressing clinical problem for both naturally menopausal women and breast and ovarian cancer patients, with a high societal and personal cost. Hot flashes are poorly understood, and animal modeling has been scarce, which has substantially hindered the development of non-hormonal treatments. An emerging factor in the hot flash experience is the role of anxiety and stress-related stimuli, which have repeatedly been shown to influence the bother, frequency, and severity of hot flashes. Causal relationships are difficult to determine in a clinical setting, and the use of animal models offers the ability to elucidate causality and mechanisms. The first part of this work details the development and validation of novel animal models of hot flashes using clinically relevant triggers (i.e., compounds or stimuli that cause hot flashes in clinical settings), which also increase anxiety symptoms. These studies revealed that these triggers elicited strong (7-9 °C) and rapid hot flash-associated increases in tail skin temperature in rats. In a surgical ovariectomy rat model of menopause, which typically exhibit anxiety-like behavior, hot flash provocation revealed an ovariectomy-dependent vulnerability, which was attenuated by estrogen replacement in tested models. An examination of the neural circuitry in response to the most robust flushing compound revealed increased cellular activity in key thermoregulatory and emotionally relevant areas. The orexin neuropeptide system was hyperactive and presented as a novel target; pretreatment with selective and dual orexin receptor antagonists significantly diminished or eliminated, respectively, the response to a hot flash provocation in ovariectomized rats. The insertion/deletion polymorphism of the serotonin transporter has been linked to increased anxiety-associated traits in humans, and subsequent studies prolonged hot flashes in SERT+/- rats, which also caused hot flashes in highly symptomatic women. These studies indicate the orexin system may be a novel non-hormonal treatment target, and future studies will determine the therapeutic importance of orexin receptor antagonists for menopausal symptoms.

No description available.

No description available.

Les estrogènes confèrent aux femmes une protection cardiovasculaire jusqu’à la ménopause. En effet, la perte des fonctions ovariennes engendre plusieurs désordres du profil lipidique qui s’accompagnent d’une accumulation de triglycérides au foie appelée stéatose hépatique. Le retrait des estrogènes perturbe de nombreuses voies de contrôle de la cholestérolémie, provoquant simultanément une hypercholestérolémie et une stéatose hépatiques. Toutefois, à ce jour, les mécanismes d’action du retrait des estrogènes sur le métabolisme du cholestérol favorisant le stockage de triglycérides au foie demeurent imprécis. À cet égard, les travaux de cette thèse visaient à clarifier l’ensemble des effets du retrait des estrogènes sur le métabolisme du cholestérol pouvant mener à la pathogenèse de la stéatose hépatique. Lors de la première étude, l’ovariectomie (Ovx) chez la rate, un modèle bien établi de la stéatose, avait permis d’identifier la voie d’assemblage des lipoprotéines à très faible densité (VLDL) comme élément contributif à la stéatose. La voie des VLDL reliant étant également une voie de transport du cholestérol, l’étude suivante a été réalisée afin de comprendre le rôle du cholestérol alimentaire sur les lipides hépatiques. Dans cette deuxième étude, le modèle de la diète riche en lipides et en cholestérol (HFHC), aussi reconnu pour induire une stéatose hépatique, a permis d’établir des liens étroits entre le métabolisme du cholestérol et celui des lipides hépatiques. Étonnamment, de manière similaire à l’Ovx, la diète HFHC perturbait la voie d’assemblage des VLDL. En outre, les données recueillies au cours de ces travaux indiquaient qu’une dysrégulation du métabolisme des acides biliaires avait contribué à la sévérité de la stéatose hépatique induite par cette diète HFHC. Dans la continuité de ces deux premiers projets, nous nous sommes intéressés aux effets concomitants du retrait des estrogènes et d’une diète HFHC sur la stéatose hépatique. De manière intéressante, lorsque combinés, l’Ovx et la diète HFHC potentialisaient non seulement l’accumulation de lipides hépatiques, mais également les perturbations moléculaires des voies sous-jacentes à la stéatose, dont l’assemblage des VLDL et de la sécrétion d’acides biliaires. Dans l’ensemble, les données présentées dans la revue de littérature et dans les trois études reliées à cette thèse indiquent qu’une dysrégulation du métabolisme du cholestérol en réponse au retrait des estrogènes entraîne des complications favorisant l’accumulation de lipides dans le foie. / Estrogens confer to women a cardiovascular protection until menopause. Indeed, the loss of ovarian functions leads to several lipid disorders along with hepatic triglycerides accumulation called hepatic steatosis. Estrogen withdrawal disrupts several cholesterol metabolism pathways that results in both hypercholesterolemia and hepatic steatosis. However, to date, the precise mechanisms by which estrogen withdrawal affect cholesterol metabolism pathways that favour lipid storage in the liver are unclear. In this regard, works in the present thesis aimed at elucidate the effects of estrogen withdrawal on cholesterol metabolism involved in hepatic steatosis pathogenesis. In the first study, estrogen withdrawal by ovariectomy (Ovx), a well established model for hepatic steatosis and hypercholesterolemia, had enabled the identification of very low density lipoprotein (VLDL) pathway as a contributory element for hepatic steatosis. Since the VLDL pathway relates lipids and cholesterol metabolism, we conducted the second study to explore the role of dietary cholesterol on hepatic lipids. In the second study, the high fat/high cholesterol (HFHC) diet, also recognized as a model for hepatic steatosis development, was used to explore links between cholesterol metabolism and hepatic fat accumulation. Surprisingly, HFHC diet also disrupted the VLDL pathway. Additionally, data provided in this study indicated that a dysregulation of bile acids metabolism might have contributed to the severity of hepatic steatosis induced by the HFHC diet. As a continuation of these projects, we were interested in the concomitant effects of estrogen withdrawal and HFHC diet on hepatic lipid accretion. Interestingly, when combined, Ovx and HFHC diet not only potentiated hepatic lipid accumulation but also molecular disruptions involved in underlying pathways for hepatic steatosis including the VLDL pathway and bile acid secretion. Overall, data presented in the review of litterature and provided by the three studies related to the present thesis indicate that cholesterol metabolism dysregulation following estrogen withdrawal result in complications that favour hepatic lipid accumulation.

La stéatose hépatique et la détérioration du profil lipidique plasmatique sont des pathologies métaboliques favorisées par la carence œstrogénique post-ménopausique. Cependant les mécanismes à la base de ces pathologies n’ont été que très peu étudiés. Le but de cette thèse a été d’investiguer les mécanismes moléculaires possibles à l’origine de l’hypercholestérolémie et de l’accumulation des lipides (triglycérides : TG et cholestérol) dans le foie en utilisant un modèle animal de la ménopause, la rate Sprague Dawley ovariectomisée (Ovx). Nous avons également examiné si le changement des habitudes de vie comme la pratique de l’exercice physique pouvait prévenir ou corriger les modifications induites par l’Ovx. Enfin, rosuvastatine (statine) a été utilisée comme thérapie pharmacologique de l’hypercholestérolémie dans le but de comprendre son effet au niveau moléculaire chez la rate Ovx. L’objectif de la première étude était de déterminer comment l’Ovx peut affecter les niveaux de TG et de cholestérol dans le foie des rates nourries avec une diète riche en lipides (HF : 42% gras). Les rates ont été soumises à la diète HF ou normale pendant 6 semaines avant d’être Ovx ou Sham (ovariectomie simulée), puis maintenues aux mêmes conditions diététiques pour 6 autres semaines. L’Ovx a provoqué une accumulation de TG dans le foie, mais pas la diète HF seule. Cependant, lorsque l’Ovx était combinée à la diète HF, l’accumulation des TG était beaucoup plus importante comparé à ce qui était observé chez les rates Ovx soumises à la diète normale. L’expression génique (ARNm) de CPT1 (Carnitine palmitoyltransferase 1), PGC1α (Peroxisome proliferator-activated receptor gamma, coactivator 1) et PPARα (Peroxysome proliferetor activated receptor alpha) intervenant dans l’oxydation des acides gras dans le foie était augmentée par la diète HF (p ˂ 0.001; p ˂ 0.01; p ˂ 0.05 respectivement) ; mais atténuée (p ˂ 0.05; p ˂ 0.05; p ˂ 0.07 respectivement) lorsque les rates ont été Ovx, favorisant ainsi l’accumulation des TG dans le foie. La combinaison de la diète HF à l’Ovx a également provoqué une hypercholestérolémie et une accumulation de cholestérol dans le foie malgré la diminution de l’expression de la HMGCoA-r (3-hydroxy-3-methylglutaryl-CoA reductase), enzyme clé de la synthèse du cholestérol. Ceci était associé à l’inhibition de l’expression génique de CYP7a1 (Cytochrome P450, family 7, subfamily a, polypeptide 1), suggérant une diminution de la synthèse des acides biliaires. Ayant constaté dans la première étude que l’Ovx élevait les niveaux de cholestérol hépatique et plasmatique, nous nous sommes fixés comme objectif dans la deuxième étude d’évaluer les effets de l’Ovx sur l’expression génique des transporteurs et enzymes responsables du métabolisme du cholestérol et des acides biliaires dans le foie et l’intestin, et de vérifier si l’exercice sur tapis roulant pouvait prévenir ou corriger les changements causés par l’Ovx. L’hypercholestérolémie constatée chez les rates Ovx comparativement aux Sham était accompagnée de la diminution de l’expression génique des récepteurs des LDL (R-LDL), des résidus de lipoprotéines (LRP1), de SREBP-2 (Sterol regulatory element binding protein 2) et de PCSK9 (Proprotein convertase subtilisin/kexin type 9) dans le foie, suggérant une défaillance dans la clairance des lipoprotéines plasmatiques. L’Ovx a aussi inhibé l’expression génique de la MTP (Microsomal triglyceride transfer protein) et stimulé celle de SR-B1 (Scavenger receptor class B, member 1); mais aucun changement n’a été observé avec CYP7a1. Ces changements moléculaires pourraient par conséquent favoriser l’accumulation de cholestérol dans le foie. L’exercice physique n’a pas corrigé les modifications causées par l’Ovx sur l’expression génique de ces molécules au niveau hépatique à l’exception de SREBP-2. Par contre, au niveau intestinal (iléum), l’exercice sur tapis roulant a inhibé l’expression génique des marqueurs moléculaires intervenant dans l’absorption des acides biliaires (OSTα/β, FXR, RXRα, Fgf15) et du cholestérol (LXRα, NCP1L1) au niveau de l’iléum chez les rates Sham entraînées. Ces adaptations pourraient prévenir le développement de l’hypercholestérolémie protégeant en partie contre la survenue de l’athérosclérose. Au vue des effets délétères (hypercholestérolémie et diminution de l’expression du R-LDL, PCSK9, LRP1, SREBP-2 et HMGCOA-r dans le foie) causés par l’Ovx sur le métabolisme du cholestérol constatés dans l’étude 2, la 3ième étude a été conçue pour évaluer l’efficacité de rosuvastatine (Ros) sur l’expression génique de ces marqueurs moléculaires chez les rates Ovx sédentaires ou soumises à l’entraînement volontaire. Ros a été administrée aux rates Ovx pendant 21 jours par voie sous-cutanée à la dose de 5mg/kg/j à partir de la 9ième semaine après l’Ovx. Ros n’a pas diminué la concentration plasmatique de LDL-C et de TC chez les rates Ovx. Par contre, Ros a stimulé (P ˂ 0.05) l’expression génique de PCSK9, SREBP-2, LRP1, HMGCoA-r et ACAT2 (Acyl-CoA cholesterol acyltransferase) mais pas significativement (P = 0.3) celle du R-LDL dans le foie des rates Ovx sédentaires et entraînées. Ros n’a pas réduit la concentration plasmatique de LDL-C probablement à cause de l’induction plus importante de PCSK9 par rapport au R-LDL. Cependant, la stimulation de LRP1 par Ros protège partiellement contre la survenue des maladies cardiovasculaires. En conclusion, les études de cette thèse indiquent que la baisse du niveau des œstrogènes entraîne des changements radicaux du métabolisme hépatique des TG et du cholestérol provoqués par des altérations de l’expression des gènes clés des voies métaboliques associées. / Hepatic steatosis and plasma lipid profile deterioration are metabolic diseases favored by post-menopausal estrogen deficiency. However, mechanisms underlying these diseases have not been systematically adressed. The aim of this thesis was to investigate molecular mechanisms causing hypercholesterolemia and lipids (triglycerides: TG and cholesterol) accumulation in the liver using animal model of menopause, the ovariectomized (Ovx) Sprague Dawley rat. We also examined whether lifestyle modifications such as physical activity can prevent or correct changes induced by Ovx. Finally, rosuvastatin (statine) was used as a pharmacological therapy of hypercholesterolemia in order to understand its effect at the molecular level in Ovx rats. The first study was designed to determine how the Ovx may affect levels of TG and cholesterol in the liver of rats fed a high-fat diet (HF: 42% fat). Rats were submitted to a HF or a normal diet for 6 weeks prior to Ovx or being sham operated, and then kept on the same diets for another 6 weeks. The Ovx increased liver TG content, but not the HF diet alone. However, the combination of Ovx and HF diet resulted in a greater liver TG accumulation than that observed in Ovx submitted to normal diet. The mRNA levels of CPT-1, PGC1 and PPARα involved in liver lipid oxidation significantly increased in rats fed the HF diet (p ˂ 0.001; p ˂ 0.01; p ˂ 0.05 respectively); but this increase was substantially less if HF fed rats were Ovx (p ˂ 0.05; p ˂ 0.05; p ˂ 0.07 respectively), thus favouring TG accumulation in the liver. The combination of HF diet and Ovx also induced hypercholesterolemia and an increase in liver total cholesterol content, in spite of the reduction of liver HMGCoA-r gene expression, the key enzyme for cholesterol synthesis. This was also associated with a decrease of liver CYP7a1 gene expression, suggesting a reduction in bile acids synthesis. Having found in the first study that the Ovx increases liver and plasma cholesterol levels, we aimed in the second study at determining the effects of Ovx on gene expression of hepatic and intestinal transporters and enzymes involved in cholesterol and bile acids metabolism; and to verify whether treadmill exercise could prevent or correct changes induced by Ovx. The Ovx resulted in hypercholesterolemia associated with a reduction in gene expression of hepatic low-density lipoprotein receptor (LDL-R), lipoprotein remnants receptor (LRP1), SREBP-2 and PCSK9, suggesting a failure in the clearance of plasma lipoproteins particles. The Ovx also inhibited the expression of MTP and stimulated that of SR-B1 in the liver, but no change was observed with CYP7a1. These molecular changes might, therefore, favor cholesterol accumulation in the liver. Exercise training did not correct the deleterious effects caused by Ovx on gene expression of these molecular markers in the liver with the exception of SREBP-2. However, in the intestine (ileum) treadmill exercise reduced gene expression of molecular markers involved in the absorption of bile acids (OSTα/β, FXR, RXRα, Fgf15) and cholesterol (LXRα, NCP1L1) in Sham trained rats compared to sedentary rats. This could prevent the development of cholestasis and hypercholesterolemia protecting partially against the onset of atherosclerosis. In view of the deleterious effects (hypercholesterolemia and decreased in gene expression of LDL-R, PCSK9, LRP1, SREBP-2 and HMGCoA-r in the liver) caused by Ovx on cholesterol metabolism observed in the second study, the 3rd study was designed to test the effect of rosuvastatin (Ros) on gene expression of these molecular markers in Ovx sedentary rats or in Ovx rats submitted to voluntary training. Ros was injected to Ovx rats subcutaneously at dose of 5mg/kg/day during 21 days from the ninth week after ovariectomy. Ros failed to decrease plasma LDL-C and TC in Ovx rats. In contrast, Ros increased (P ˂ 0.05) PCSK9, SREBP-2, LRP1, HMGCoA-r and ACAT2 but not significantly (P ˂ 0.3) LDL-R mRNA in the Ovx sedentary and trained rat liver. Ros failed to decrease plasma LDL-C in Ovx rats probably because of a stronger induction of PCSK9 than LDL-R gene expression. However by increasing LRP1 expression, Ros could decrease circulating lipoprotein remnants and, therefore, protects partially against the onset of cardiovascular diseases. In conclusion, the studies of this thesis indicate that the decrease of ovarian estrogen levels causes radical changes in hepatic TG and cholesterol metabolism caused by alterations in the expression of key genes associated with metabolic pathways.

INTRODUÇÃO: O hipoestrogenismo pode determinar perda da massa mineral óssea, diminuindo a qualidade do osso. Assim, vários fármacos são ministrados para evitar esta perda, porém, podem determinar efeitos colaterais importantes. Portanto, questiona-se se o emprego do estrogênio associado a estas substâncias poderia minimizar os efeitos adversos e manteria a massa mineral óssea. Contudo, há poucas informações sobre os efeitos destas combinações. Esta pesquisa tem como objetivo avaliar a ação do estrogênio, raloxifeno e do extrato de soja rico em gensteína, isolado ou combinado no osso de ratas ovariectomizadas. MATERIAIS E MÉTODOS: No nono dia de nascimento, todas as ratas receberam propionato de testosterona (0,1 g/g). No sexto mês de idade, os animais do controle fisiológico foram identificados como GI e receberam apenas o veículo (propilenoglicol em 0,5 ml/dia) durante o experimento e os outros que receberam testosterona foram ovariectomizados e divididos aleatoriamente em seis grupos: GII veículo (controle castrado, n=6); GIII - estrogênio conjugados eqüinos (ECE, (50 g/Kg/dia, n=8); GIV raloxifeno (RAL, 0,75 mg/kg/dia, n=8); GV extrato de soja enriquecido com genisteína (ESG, 300 mg/kg/dia, n=7); GVI ECE + ESG (50 g/Kg/dia + 300 mg/kg/dia, n=7); GVII - ECE+RAL (50 g/Kg/dia + 0,75mg/kg/dia, n=6). Após três meses da cirurgia, os fármacos foram ministrados por 120 dias consecutivos. Posteriormente, os animais foram sacrificados sob anestesia, sendo retirada a tíbia esquerda para rotina histológica. Os cortes histológicos foram corados pela hematoxilina-eosina para avaliar a microarquitetura óssea. Foram feitos procedimentos imunoistoquímicos, de imunofluorescência e PCR para quantificar as principais proteínas ósseas estruturais (colágeno tipo I, osteocalcina, osteopontina e osteoprotegerina), bem como de seus respectivos RNA mensageiros. Os dados foram analisados pelos testes de ANOVA e Tukey. RESULTADOS: Todos os tratamentos determinaram aumento da quantidade de osso trabecular (p<0,05). As fibras totais de colágeno apresentaram-se aumentadas em todos os grupos tratados, exceto com o raloxifeno. Já as fibras finas de colágeno diminuíram apenas no grupo tratado com estrogênio. As frações de colágeno tipo I, mostraram-se aumentadas nos grupos tratados com estrogênio e sua asssociação com o raloxifeno. O colágeno tipo III esteve aumentado no grupo tratado com estrogênio em associação com extrato de soja rico em genisteína. Em relação às proteínas não colagenosas, a osteoprotegerina apresentou-se aumentada nos grupos tratados com estrogênio, suas associações e com o extrato de soja rico em genisteína. A osteopontina esteve diminuída em todos os grupos tratados e a osteocalcina mostrou-se aumentada apenas no grupo tratado com ralolxifeno, em comparação ao grupo castrado (p<0,05). Não houve diferença estatística significante do PCR em tempo real na análise dos transcritos entre os grupos estudados. CONCLUSÃO: A combinação de estrogênio com raloxifeno ou extrato de soja rico em genisteína não trouxe benefícios adicionais na qualidade do tecido ósseo, como ocorreu com esses fármacos isoladamente / INTRODUCTION: Hypoestrogenism can determine bone mineral loss, resulting in decreased bone quality. To prevent that process, several drugs are administered, which can lead, however, to important side effects. Therefore, it is questionable whether the use of estrogen associated with those substances could minimize the adverse effects and maintain bone mineral mass. There is little information on the effects of those compounds. This research aims to evaluate the action of unopposed estrogen or combined with raloxifene and genistein-rich soy extract on ovariectomized adult female rats. MATERIALS AND METHODS: On the ninth day of birth, rats received, testosterone propionate (0.1 mg / g). On the sixth month, animals in the physiological control were identified as GI and received only the vehicle (propylene glycol at 0.5 ml / day) during the experiment and the other which was administered testosterone underwent ovariectomy and divided randomly into six groups: GII - vehicle (control castrated, n = 6); GIII - conjugated equine estrogen (CEE, 50 mg / kg / day, n = 8); GIV - raloxifene (RAL, 0.75 mg / kg / day, n = 8) ; GV - soy extract enriched with genistein (ESG, 300 mg / kg / day, n = 7), GVI - ECE + ESG (50 mg / kg / day + 300 mg / kg / day, n = 7); GVII - ECE + RAL (50 mg / kg / day + 0.75mg/kg/day, n = 6).Three months after the surgery, drugs were consecutively administered for 120 days. Subsequently, the animals were sacrificed on anesthesia and their left tibiae were removed for routine histology. The histological sections were stained by hematoxylin-eosin to evaluate bone microarchitecture. Immunohistochemical, immunofluorescence and PCR procedures were performed to quantify the main structural bone proteins (type I collagen, osteocalcin, osteopontin, and osteoprotegerin) as well as their mRNA. The data were analyzed by ANOVA and Tukey test. RESULTS: All treatments led to increased amounts of trabecular bone (p <0.05). The total collagen fibers had to be enlarged in all treated groups, except with raloxifene. Already thin collagen fibers decreased only in the group treated with estrogen. The fractions of type I collagen, were increased in groups treated with estrogen and its asssociação with raloxifene. Type III collagen was increased in the group treated with estrogen in combination with soybean extract rich in genistein. Regarding the non-collagenous proteins, the increased osteoprotegerin presented in groups treated with estrogen, and their associations with soy extract rich in genistein. The osteopontin was decreased in all treated groups and osteocalcin was increased only in the treated group ralolxifeno, compared to the castrated group (p <0.05). There was no statistically significant difference from the real-time PCR analysis of transcribed between the groups. CONCLUSION: The combination of estrogen with raloxifene or genistein-rich soy extract was uncapable of bringing additional benefits to the quality of bone tissue as observed with those drugs alone

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No. of bitstreams: 1 NAT?LIA_PREDELLA_CIGNACHI_TES.pdf: 11102267 bytes, checksum: 121fbf4d2b9ae1c4a36e21d23ab3140d (MD5) Previous issue date: 2018-01-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This thesis encompasses two parts: firstly, we compared the bone healing in female and male mice, after induction of type 1 diabetes (T1D); secondly, the bone regeneration was evaluated in a menopause model induced by bilateral ovariectomy (OVX), with or without T1D induction. For the part I, the animals (female and male) were initially assigned into two groups, namely control or T1D (elicited by streptozotocin; STZ). In the part II, the females were divided into four experimental groups: sham-operated or OVX, with or without STZ T1D induction. After T1D induction, a monocortical femoral defect was created. In either parts of the present study, we evaluated the effects of supplementation with vitamin D3 and/or insulin. In the second part, the effects of estrogen replacement were also analyzed. Following 21 days of bone defect creation, the animals were euthanized; the femurs and blood were collected for posterior analysis. Both T1D females and males presented a reduction in body weight gain, associated with hyperglycemia. There were no changes in the serum levels of the pro-inflammatory cytokines [interleukin-1? (IL-1?), tumor necrosis factor (TNF) and interferon-? (IFN-?)] in all the evaluated groups. T1D mice of both sexes presented a delayed bone regeneration, according to the histological and micro-CT assessment. The supplementation with vitamin D3 restored the bone healing in female and male T1D mice, reaching values close to controls. The insulin therapy improved the bone remodeling in T1D mice of both sexes, but the effects of this hormone were superior in males. The evaluation of osteoclast activity did not reveal significant differences among the experimental groups. Real time PCR revealed slight differences in the mRNA expression of two transcription factors related to osteoblast differentiation, namely runx2 and osterix, as measured in the area into the bone defect. A higher upregulation of both factors was seen in T1D males treated with vitamin D3. Conversely, vitamin D3-treated T1D females displayed an upregulation of insulin-like growth factor 1 (IGF-1), further indication sex-related differences for the treatments. Besides the experimental protocols described for the 12 part I of this thesis, in the part II, we also evaluated some behavioral locomotor parameters and serum levels of calcium and alkaline phosphatase. OVX animals presented increased body weight gain, accompanied by uterus atrophy. Otherwise, T1D induction elicited a reduction of body weight gain, which was more pronounced in OVX-T1D animals. Serum levels of alkaline phosphatase were divergent in the non-diabetic and T1D OVX animals. Calcium or cytokine levels were similar in all the experimental groups. The sham-operated T1D, the non-diabetic OVX and the OVX-T1D groups presented a delayed bone regeneration, as indicated by histological and micro-CT analysis. Estrogen replacement improved the bone healing in all OVX groups. There was a trend toward an upregulation of IGF-1 mRNA in non-diabetic OVX animals, which was not mirrored in OVX-T1D mice. Locomotor parameters remained unaltered, except by a general reduction of rearing numbers in T1D animals. / A presente tese est? dividida em duas partes: na parte I, comparou-se a regenera??o ?ssea em camundongos f?meas e machos, com diabetes do tipo 1 (T1D). Na parte II, foi avaliada a regenera??o ?ssea no modelo de menopausa experimental induzido por ovariectomia (OVX), com ou sem T1D. Na parte I, os animais (machos e f?meas) foram divididos em dois grandes grupos: controle e T1D (induzido por estreptozotocina; STZ). Na parte II, os animais foram divididos em quatro grandes grupos: f?meas falso-operadas e OVX, com ou sem T1D. Ap?s a indu??o do T1D, foi criado um defeito ?sseo monocortical no f?mur. Nas duas partes do trabalho, foram avaliados os efeitos da suplementa??o com vitamina D3 e/ou insulina. Na segunda parte, tamb?m se avaliou o efeito da reposi??o hormonal com estradiol. Decorridos 21 dias do procedimento da cria??o do defeito, os animais foram eutanasiados; o f?mur e o sangue foram coletados para an?lises posteriores. Tanto as f?meas, quanto os machos T1D, apresentaram uma redu??o do ganho de peso corporal, associado ? hiperglicemia. N?o houve altera??es nos n?veis s?ricos das citocinas pr?-inflamat?rias interleucina-1? (IL-1?), fator de necrose tumoral (TNF) ou interferon-? (IFN?). Os animais T1D, de ambos os sexos, apresentaram um comprometimento na regenera??o ?ssea, como demonstrado pelas an?lises histol?gicas e de micro-CT. A suplementa??o com vitamina D3 reestabeleceu a regenera??o ?ssea em f?meas e machos T1D, apresentando valores pr?ximos aos encontrados nos animais do grupo controle. A terapia com insulina melhorou a remodela??o ?ssea nas f?meas e machos T1D; por?m, os efeitos foram mais pronunciados nos machos. A avalia??o da atividade osteocl?stica n?o revelou diferen?as significativas entre os grupos experimentais, ap?s a indu??o de T1D, em machos ou f?meas. Os resultados do PCR em tempo real para runx2 e osterix (dois fatores de transcri??o relacionados aos osteoblastos), no tecido ?sseo, n?o demonstraram nenhuma diferen?a significativa, exceto por um aumento nos n?veis de RNAm dos dois fatores nos camundongos machos T1D, que receberam suplementa??o com vitamina 10 D3. Por outro lado, f?meas T1D que receberam vitamina D3 apresentaram um aumento na express?o dos n?veis de RNAm para o fator de crescimento semelhante ? insulina do tipo 1 (IGF-1), quando comparado com os machos que tiveram o mesmo tratamento, sugerindo assim, diferen?as relacionadas ao sexo. Al?m das an?lises j? mencionadas anteriormente, na parte II da tese, par?metros comportamentais e n?veis s?ricos de c?lcio e fosfatase alcalina tamb?m foram analisados. Os resultados da segunda parte do trabalho demonstraram que os animais submetidos a OVX tiveram um aumento do peso corporal, com atrofia uterina. Em contrapartida, quando foi induzido T1D, houve uma diminui??o do peso corporal mais acentuada no grupo OVX que no grupo falso-operado. Os animais falso-operados e OVX T1D apresentaram hiperglicemia, confirmando o desenvolvimento do diabetes. Os n?veis s?ricos de fosfatase alcalina foram divergentes entre os grupos n?o-diab?ticos OVX e OVX T1D. N?o houve varia??es dos n?veis de c?lcio. Os animais falso-operados T1D, n?o diab?ticos OVX e OVX T1D apresentaram preju?zos similares na regenera??o ?ssea, como observado pelas an?lises histol?gicas e imagens de micro-CT. A reposi??o com estradiol melhorou a cicatriza??o ?ssea nos animais n?o-diab?ticos OVX e OVX T1D. Houve uma tend?ncia ao aumento nos n?veis de RNAm de IGF-1 no grupo OVX, o que n?o foi observado quando da associa??o de T1D e menopausa. N?o foram observadas diferen?as na atividade locomotora dos animais com T1D e/ou OVX, a n?o ser por uma diminui??o no n?mero de rearings no grupo falso-operado T1D, independente do tratamento com vitamina D3, insulina e estradiol, de forma isolada ou em associa??o.

Os fatores idade e sexo modificam a experiência dolorosa em animais e seres humanos. Os efeitos dos hormônios gonadais têm sido estudados em diversos modelos experimentais de dor, no entanto, o efeito do envelhecimento na percepção à dor carece de mais investigação. O efeito do envelhecimento na dor neuropática ainda não está bem estabelecido. Neste estudo se procurou avaliar possíveis variações na percepção da dor da hiperalgesia mecânica, em função da idade, presença e ausência de hormônios gonadais e sexo em ratos Wistar machos e fêmeas, jovens e idosos no modelo de dor neuropática, ligadura da quinta raiz lombar. Os animais foram divididos nos seguintes grupos: ratos jovens orquiectomizados e não-orquiectomizados, ratos idosos orquiectomizados e não-orquiectomizados, ratas jovens ooforectomizadas com ou sem reposição de 17beta-estradiol e ratas idosas. Foi testado o limiar de retirada da pata após estímulo mecânico antes da ligadura e no 7º, 14º, 21º e 28o dias após a ligadura. Os resultados mostraram que todos os animais apresentaram comportamento hiperalgésico após ligadura da quinta raiz lombar durante os 28 dias de observação. A hiperalgesia ocorreu independentemente do sexo do animal, da presença ou ausência de hormônios gonadais ou idade. Não houve diferença entre ratos jovens e idosos não-orquiectomizados (p = 0,420), entre ratos jovens e idosos orquiectomizados (p = 0,560). Entre os ratos idosos com e sem orquiectomia houve diferença no 14º (p = 0,038) e 28º (p = 0,002) dias. Ratas jovens ooforectomizadas sem reposição de 17beta-estradiol apresentaram menor hiperalgesia que ratas ooforectomizadas com reposição durante todo o período (p = 0,001). Não houve diferença entre ratos idosos orquiectomizados e ratas idosas (p = 0,09). Ratos jovens não-orquiectomizados apresentaram menor hiperalgesia mecânica que ratas jovens ooforectomizadas com reposição de 17beta-estradiol (p = 0,001), o mesmo não ocorreu entre machos e fêmeas jovens gonadectomizados sem reposição hormonal (p = 0,511). Ratas jovens ooforectomizadas sem reposição de 17beta-estradiol e ratas idosas mostraram diferença apenas no 7º dia (p = 0,002). Os resultados permitiram concluir que a reposição de 17beta-estradiol aumentou a hiperalgesia mecânica aos estímulos mecânicos após ligadura da quinta raiz lombar em ratas jovens ooforectomizadas, a hiperalgesia mecânica não diferiu entre os sexos em ratos jovens machos e fêmeas, a presença da gônada masculina diminuiu a hiperalgesia mecânica em ratos idosos e que houve diminuição da hiperalgesia mecânica em ratas idosas / Age and sex modify the pain experience in animals and humans. The effects of gonadal hormones have been studied in various experimental pain models, however, the effect of aging on pain perception needs further investigation. The effect of aging on neuropathic pain is not well established. In this study, we sought to determine how aging and gonadal hormones affect mechanical hyperalgesia using spinal nerve ligation as a neuropathic pain model in aged and young male and female Wistar rats. Animals were divided into seven groups: aged female, ovariectomized young females with 17beta-estradiol replacement, ovariectomized young females without 17beta-estradiol replacement, orchiectomized and non-orchiectomized aged and young males. Rats were tested for mechanical hyperalgesia in the plantar surface of the left hindpaw before nerve ligation and on days 7, 14, 21 and 28 after nerve ligation. All animals of all groups showed mechanical hyperalgesic behavior after spinal nerve ligation during entire period of 28 days. Hyperalgesia was independent of the sex of the animal, the presence or absence of gonadal hormones or age. There was no difference between non-orchiectomized aged and young males (p = 0.420), and between orchiectomized aged and young males (p = 0.560). There was difference between aged male rats with and without orchiectomy in days 14 (p = 0.038) and 28 (p = 0.002). Young ovariectomized female rats without 17beta-estradiol replacement had less hyperalgesia than young ovariectomized female rats with replacement (p = 0.001). There was no difference between aged orchiectomized male rats and old female rats (p = 0.09). Young non-orchiectomized male rats showed less mechanical hyperalgesia than young ovariectomized female rats with 17beta-estradiol replacement (p = 0.001), that did not occur between young orchiectomized males rats and young ovariectomized females rats without 17beta-estradiol replacement (p = 0.51). Young ovariectomized female rats without 17beta-estradiol replacement and old female rats showed differences only on day 7 (p = 0.002). These data suggest that estradiol presented a pronociceptive effect in young female rats in mechanical hyperalgesia in the neuropathic pain model, spinal nerve ligation, withdrawal threshold did not differ between sex, the presence of male gonadal hormones reduces mechanical hyperalgesia in old male rats and there is reduced mechanical hyperalgesia in aged female rats