A acidose metabólica causa perda de mineral ósseo e a estimulação mecânica causa remodelamento ósseo adaptativo. A reabsorção óssea que caracteriza essas mudanças ósseas depende da acidificação extracelular pela secreção vetorial de H+ pelos osteoclastos. A H+-ATPase vacuolar em paralelo com o trocador Cl-/H+ (CLC7) são os mecanismos conhecidos envolvidos na reabsorção óssea, entretanto, os osteoclastos também expressam canais para H+ dependentes a voltagem. Este trabalho foi realizado para avaliar a contribuição dos canais para H+ na função celular visando à compreensão de seu relacionamento com a H+-ATPase vacuolar e o CLC7 (1); analisar se o fluxo de fluido extracelular modifica a secreção de H+ (2) e avaliar a diferenciação dos osteoclastos in vitro sob acidose metabólica devido à redução do HCO3- (3). Osteoclastos de ratos Wistar foram obtidos diretamente dos animais ou foram diferenciados in vitro (com M-CSF e RANKL) e semeados sobre vidro, plástico ou substratos mineralizados em <font face=\"Symbol\">&#945;-MEM + 10% SFB, em pH 7,4 ou 6,9, e então mantidos em incubadora com 5% CO2, a 37<font face=\"Symbol\">&#176;C. A diferenciação celular foi avaliada pela contagem de células TRAP-positivas ou de núcleos marcados por DAPI. A secreção de H+ foi avaliada por epifluorescência, utilizando-se BCECF-AM, sensível a pH. Os registros do pH intracelular foram feitos na vigência de soluções tamponadas por HEPES, na ausência de CO2/HCO3- (pH 7,4, 300 mOsm/L H2O, a 37<font face=\"Symbol\">&#176;C), na presença ou ausência de perfusão contínua de fluido extracelular a uma velocidade de 5 ml/min. Na ausência de perfusão, os osteoclastos exibiram variações cíclicas do pHi (acidificação e alcalinização espontâneas), com período de 12 a 45 minutos (n = 35) e amplitude de 0,12 a 1,43 unidades de pHi. As oscilações não foram abolidas por concanamicina (100 mM) (n = 3), por NPPB (100 <font face=\"Symbol\">mM) (n = 3), na ausência de Na+ extracelular (n = 5) ou na ausência de Cl- extracelular (n = 3). O fluxo de fluido aboliu as oscilações e a ausência de Cl- extracelular modificou significativamente seu padrão. Na ausência de perfusão, a secreção de H+ após acidificação intracelular induzida foi abolida por Zn2+ (100 <font face=\"Symbol\">mM) (n = 5). Além disso, na presença de perfusão, a secreção de H+ após acidificação intracelular induzida foi abolida por NPPB (n = 4) e não foi abolida por bafilomicina (200 nm) (n = 3). A acidose metabólica não modifica o número de osteoclastos diferenciados in vitro, entretanto, o tratamento das culturas com Zn2+ causou redução do numero de células mononucleares e aumento relativo do número de osteoclastos multinucleados em relação ao controle tanto em pH 7,4 quanto em pH 6,9. / Metabolic acidosis can cause a loss of bone mineral and the mechanic stimulation can cause adaptative bone remodeling. The bone resorption characteristic of these bone changes aforementioned depends on the extracellular acidification by osteoclastmediated proton secretion. The H+ secretion by vacuolar H+-ATPase together with Clsecretion through a Cl-/H+ exchanger (CLC7) are the known mechanisms involved in the bone resorption; however, osteoclasts also express voltage-gated proton channels. The proposed aims of these work were to evaluate the contribution of proton channels in the osteoclast function for better understanding its relation with vacuolar H+-ATPase and CLC7 (1); to analyze whether the flow of extracellular fluid modifies the H+ secretion or not (2); and to analyse the osteoclast differentiation in vitro under metabolic acidosis due to HCO3- reduction (3). Osteoclasts were freshly isolated or generated from bone marrow precursor cells (using M-CSF and RANK- L) from of Wistar rats. The cells were placed on glass coverslips, plastic coverslips, or on mineralized substrate in <font face=\"Symbol\">&#945;-MEM + 10% FBS, pH 7.4 or 6.9, and then maintained in a 5% CO2 incubator at 37<font face=\"Symbol\">&#176;C. The differentiation was analyzed by counting of TRAP-stained cells or DAPIstained nuclei. The H+ secretion was analysed by epifluorescence, using the pHsensitive dye BCECF-AM. The intracellular pH record was done using a standard HEPES-buffered solution free of CO2/HCO3- (pH 7.4, 300 mOsm/L H2O, at 37<font face=\"Symbol\">&#176;C), with or without continuous perfusion of extracellular fluid at a rate of 5 ml/min. In the absence of perfusion, the osteoclasts exhibit cyclic pHi variations (spontaneous acidification and alkalinization), with a period of 12 to 45 minutes (n = 35) and amplitude difference between maximal and minimal pHi of 0.12 to 1.43 units pHi. These oscillations were not abolished in the presence of oncanamycin (100 mM) (n = 3), NPPB (100 <font face=\"Symbol\">mM) (n = 3), in the absence of Na+ (n = 5) or in the absence of Cl- (n = 3) in the extracellular solution. The fluid flow itself abolished the pH oscillations and the absence of extracellular Cl- modifies significantly these patterns. In the absence of perfusion, the H+ secretion after induced intracellular acidification was abolished by Zn2+ (100 <font face=\"Symbol\">mM) (n = 5). In addition, in the presence of perfusion, the H+ secretion after induced intracellular acidification was abolished by NPPB (n = 4) and was not abolished by bafilomycin (200 nm) (n = 3). Metabolic acidosis does not modify the number of osteoclasts differentiated in vitro, however, when the cell culture was treated with Zn2+, there was a significant reduction in the number of mononuclear cells and a relative increase in the number of multinucleated osteoclasts compared to control, both in pH 7.4 and pH 6.9 medium.

INTRODUÇÃO: Os níveis séricos de fósforo (P) têm sido associados a doenças cardiovasculares e mortalidade em pacientes com doença renal crônica e na população geral. Estudos in vitro demonstram que altas concentrações de fósforo extracellular são capazes de induzir calcificação vascular e disfunção endotelial. O Fibroblast Growth Factor 23 (FGF-23) é um hormônio fosfatúrico e foi relacionado à presença de aterosclerose em pacientes idosos. OBJETIVO: O objetivo deste estudo foi investigar as relações entre P, FGF-23 e outros atores do metabolismo mineral e a ocorrência de doença arterial coronariana em pacientes com função renal preservada. MÉTODOS: Duzentos e noventa pacientes clinicamente estáveis com indicação de cineangiocoronariografia eletiva e clearance de creatinina superior a 60 ml/min/1.73 m2 foram submetidos à Tomografia Computadorizada Multislice para avaliação da calcificação coronariana e coleta de sangue para dosagens bioquímicas. A calcificação coronariana foi quantificada através do Escore de Agatston (EA) e os Escores de Friesinger e Gensini foram calculados para quantificar a obstrução coronariana. RESULTADOS: A média de idade dos pacientes foi 58,1± 9,3 anos, 81% eram hipertensos e 35,5% diabéticos. Os pacientes foram divididos em grupos de acordo com o EA utilizando-se como ponto de corte o valor de 10 Unidades Hounsfield (HU). O P sérico foi maior no grupo de pacientes com EA > 10 HU (3,63 0,55 vs 3,49 0,52mg/dL; p=0,019). Cada 1 mg/dL de elevação no P sérico associou-se a um aumento de 92% no risco de apresentar o EA > 10HU [Odds Ratio (OR) =1,92, CI 1,56-3,19; p=0,01]. Quando os pacientes foram divididos de acordo com a mediana do Escore de Friesinger (4 pontos), o grupo com valores superiores à mediana apresentou P sérico maior (3,6 0,5 vs. 3,5 0,6 mg/dl; p=0,04) e FGF-23 menor (mediana 40,3 pg/mL intervalo interquartil 24,1-62,2 vs. 45,7 pg/mL intervalo interquartil 31,7-76,1; p=0,01) quando comparado àquele com valores menores ou iguais a 4. Pacientes no tercil mais alto do escore de Gensini também apresentaram P sérico mais elevado que os demais (p<0,05). Nas análises de regressão logística uni e multivariadas, cada 1 mg/dL de elevação no P sérico implicou em um aumento de 74% no risco de apresentar o Escore de Friesinger superior à mediana (OR 1,74, CI 1,06- 2,88; p=0,03) e o FGF-23 sérico foi preditor negativo do Escore de Friesinger (OR 0,26, CI 0,11-0,63; p=0,002) Os níveis séricos de cálcio e paratormônio não mostraram associação com a presença de doença coronariana. CONCLUSÃO: Em pacientes com suspeita de doença arterial coronariana e função renal preservada, o fósforo sérico foi preditor da presença de calcificação e obstrução coronariana e houve uma associação negativa entre o FGF-23 sérico e a presença de obstrução coronariana. / INTRODUCTION: Serum phosphorus (P) has been associated with cardiovascular diseases and mortality in chronic kidney disease patients and in the general population. In vitro studies suggest that excessive phosphorus induces vascular calcification and endothelial dysfunction. Fibroblast growth factor 23 (FGF-23) is a phosphaturic hormone and has been correlated to atherosclerosis in the community. AIM: This study intended to investigate the associations between P, FGF-23 and other mineral metabolism players and coronary artery disease in patients with preserved renal function. METHODS: Two-hundred ninety patients with a creatinine clearance higher than 60ml/min/1,73m2 undergoing elective coronary angiography were submitted to Multislice Computed Tomography in order to evaluate coronary calcification and blood was collected for biochemical analyses. Coronary artery calcification was quantified using the Agatston Score (AS). Friesinger (FS) and Gensini Scores (GS) were calcutalet to quantify coronary obstruction. RESULTS: Considering the whole population, mean age was 58.1±9.3 anos, 81% were hypertensive and 35.5% were diabetics. Patients were divided according to AS using the value of 10 Hounsfield Units (HU) as the cutoff.point. Serum phosphorus was higher in patients with an AS > 10HU when compared to the group with an AS 10 HU (3.63 0.55 vs 3.49 0.52mg/dL, p=0.019). Each 1 mg/dL of elevation in the serum phosphorus implied a 92% additional risk of presenting an AS > 10 HU [Odds Ratio (OR) =1.92, CI 1.56-3.19; p=0.01]. Patients were also divided using the median Friesinger score (4 points) as the cutoff value. Serum phosphorus was higher (3.6 0.5 vs. 3.5 0.6 mg/dl, p=0.04) and intact FGF-23 was lower (median 40.3 interquartile range 24.1-62.2 pg/mL vs. 45.7 interquartile range 31.7- 76.1 pg/mL, p=0.01) in the FS > 4 group. Patientis in the higher Gensini Score tertile presented elevated serum phosphorus when compared to the other groups (p<0,05). In the uni and multivariate logistic regression analyses, a rise of 1 mg/dL of serum phosphorus carried a 74% increase in the risk of having a FS higher than 4 (OR 1.74, CI 1.06-2.88; p=0.03) and FGF-23 was a negative predictor of FS (OR 0.26, CI 0.11-0.63; p=0.002). Serum calcium and parathormone were not associated with the presence of coronary artery disease. CONCLUSIONS: In patients with suspected coronary artery disease and preserved renal function, phosphorus was predictive of both coronary artery calcification and obstruction. There was a negative association between FGF-23 and coronary obstruction

INTRODUÇÃO: Os distúrbios minerais e ósseos (DMO) da doença renal crônica (DRC) estão associados ao aumento do risco de fratura, estudos relatam cerca de 3% de fraturas neste grupo de pacientes, e as mesmas ocorrem mais precocemente quando comparadas à população geral, ou seja, 16 e 13 anos antes para homens e mulheres, respectivamente. A melhora no tratamento do DMO ainda não impactou na diminuição das fraturas, assim a melhor compreensão da fisiopatologia das mesmas provavelmente contribuiria para novas abordagens terapêuticas. OBJETIVOS: avaliar informes de fraturas, de ossos longos, de um banco de biopsias ósseas de pacientes com DRC em hemodiálise, e comparar, as características clínicas, bioquímicas e os resultados da análise histomorfométrica do osso trabecular e cortical desses pacientes com o de outros sem fraturas, pareados para idade, sexo e tempo de hemodiálise. Avaliamos também, por imunohistoquimica, a expressão de proteínas envolvidas na formação (SOST) e na mineralização óssea (DMP1, MEPE) de ambos os grupos. MÉTODOS: dezessete pacientes com fratura e igual número de controles foram estudados. RESULTADOS: A prevalência de fraturas foi de 5,5 fraturas/1000 pacientes ano a maioria deles tinha menos de 60 anos e tempo em hemodiálise inferior a 10 anos. Quanto a analise dos dados bioquímicos somente os níveis de fósforo sérico foram significativamente mais baixos nos pacientes com fratura comparada aos controles. Os resultados da análise histomorfométrica revelaram que a totalidade dos pacientes com e sem fratura apresentava doença de alta remodelação e nos fraturados detectamos menor volume e espessura trabecular, maior superfície osteóide, menor superfície de reabsorção além de menor superfície mineralizante, taxa de formação e maior tempo de intervalo para mineralização óssea quando comparados aos controles. Não encontramos diferenças na análise da espessura e porosidade cortical entre os dois grupos e a expressão da DMP1 no osso cortical foi menor e da SOST no osso trabecular foi maior nos pacientes fraturados comparados aos controles além de se associarem com parâmetros estruturais, de formação, de reabsorção e de mineralização. CONCLUSÕES: No banco de informes de biópsias ósseas analisado, encontramos alta prevalência de pacientes com fratura. Os pacientes com e sem fratura apresentavam doença de alta remodelação, porém os fraturados apresentavam maior comprometimento da microarquitetura óssea assim como menor formação e maior defeito de mineralização quando comparados aos pacientes sem fratura. A expressão de proteínas ósseas envolvidas na formação e mineralização óssea se correlacionaram com parâmetros envolvidos na remodelação óssea / INTRODUCTION: Mineral and bone disorders (BMD) of chronic kidney disease (CKD) are associated with increased risk of fracture. Studies report about 3% of fractures in this group of patients, and these occur earlier than in the general population, namely 16 and 13 years earlier for men and women, respectively. Improvement in BMD treatment has not yet impacted reduction of fractures, therefore a better understanding of the pathophysiology of fractures would probably contribute to new therapeutic approaches. OBJECTIVES: evaluate report of long bone fractures from a bank of bone biopsies from patients with CKD on hemodialysis, and compare clinical and biochemical characteristics as well as the results of the histomorphometric analysis of trabecular and cortical bone of these patients with that of others without fractures, paired for age, gender, and time on hemodialysis. We also evaluated the expression of proteins involved in formation (SOST) and bone mineralization (DMP1, MEPE) of both groups by immunohistochemistry. METHODS: seventeen patients with fracture and an equal number of controls were studied. RESULTS: The prevalence of fractures was 6%, the majority of the patients were less than 60 years old, and the time on hemodialysis was less than 10 years. Regarding the analysis of the biochemical data, only serum phosphorus levels were significantly lower in patients with fracture compared to controls. Results of the histomorphometric analysis revealed that all the patients with and without fracture had high turnover disease, and in the fractured ones we detected a smaller trabecular volume and thickness, greater osteoid surface, and smaller surface of resorption in addition to smaller mineralizing surface, formation rate and longer time interval for bone mineralization when compared to controls. We did not find differences in the analysis of thickness and cortical porosity between the two groups; the DMP1 expression in the cortical bone was smaller and the SOST in the trabecular bone was higher in the fractured patients compared to that of controls, besides being associated with structural parameters, formation, reabsorption and mineralization. CONCLUSIONS: In the database of analyzed bone biopsies, we found low prevalence of patients with fracture. Patients with and without fracture had high turnover disease, but the fractured ones presented more impaired bone microarchitecture as well as lower formation and greater mineralization defect when compared to the patients without fracture. The expression of bone proteins involved in bone formation and mineralization correlated with parameters involved in bone remodeling

Diabetic vasculopathy (DV) is the most important consequence of chronic hyperglycemia in patients with diabetes mellitus (DM). This thesis explores the interaction of blood, bone and kidney in the pathogenesis of DV by i) reviewing the current understanding of pathogenesis of macrovascular and microvascular diseases in DM to identify gaps in literature and generate hypotheses relating to various facets of DV ii) undertaking a series of prospective studies to examine these hypotheses iii) analysing the findings and integrating any new information obtained from the clinical studies into the current knowledge base and iv) generating hypotheses upon which future work might be based. The literature search was carried out with the aim of understanding current concepts of pathogenesis of DV and its potential modulators. The original reviews resulting from this process are presented in chapters 2 to 4. A series of pilot studies reported in chapters 7 to 11, were then carried out to interrogate hypotheses originating from this process. The first study was carried out in healthy individuals to define the biological variation of potential modulators of DV, namely erythropoietin (EPO), parathyroid hormone, 25 hydroxyvitamin D and 1, 25-dihydroxyvitamin D to facilitate the design and interpretation of subsequent studies. It revealed a wide biological variation of these modulators in the healthy population thus,emphasizing the need to have a control group in the subsequent study population. To examine whether tubulointerstitial dysfunction occurs before the onset of microalbuminuria, a measurement of the above mentioned parameters was carried out along with markers of tubulointerstitial injury in patients with type 1 and type 2 DM without microalbuminuria and in non-diabetic controls. It was found that tubulointerstitial dysfunction with low levels of EPO and 1, 25-dihydroxyvitamin D and higher excretion of tubular injury markers, occurs before the onset of microalbuminuria. Subsequently, diabetic and nondiabetic chronic kidney disease (CKD) patients with EPO deficiency anaemia were examined to study the effects of EPO therapy on the excretion of tubular injury markers. However, in these patient groups, we were unable to demonstrate an effect of EPO therapy on the markers of tubular injury in spite of a beneficial haematological response. To examine whether vascular calcification (VC) and bone mineral density (BMD) were linked in patients with diabetes mellitus and to explore their relationship to modulators of DV, an assessment of VC and BMD was undertaken in patients with type 2 DM with different degrees of proteinuria and normoalbuminuria. VC was assessed by CT scan and BMD by a DEXA scan. Modulators of DV were measured including serum Osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-b-ligand (RANKL). The findings were i) a high prevalence of VC and osteopenia in normoalbuminuric type 2 DM patients with normal serum creatinine ii) a weak inverse relationship between VC and osteopenia iii) proteinuric patients had worse VC but not osteopenia iv) weak relationships between OPG levels and both VC and osteopenia, masked by age in multivariate analysis. The final study examined the relationship between modulators of DV, including OPG and RANKL, and the degree of CKD. It was found that abnormalities of OPG and RANKL occur before the onset of microalbuminuria and progress with deterioration of renal function. Compared to nondiabetics, DM patients have higher OPG levels in the predialysis phase and lower levels in haemodialysis phase, a phenomenon that might indicate endothelial exhaustion in dialysis patients with DM. The derangements associated with DV seem to occur earlier than previously thought. Further work is required to untangle these complexities and to define the contribution of factors such as the adverse blood milieu, the vasculature, abnormal bone and mineral metabolism, and early tubulointerstitial damage. The findings from the studies reported here may help in the formulation of new hypotheses, which might contribute to future work in this area.

O objetivo deste estudo foi estabelecer uma correlação entre o efeito da suplementação por meio da ingestão de castanhas-do-brasil (CS) com o estado nutricional de praticantes de capoeira em relação ao selênio (Se). A importância deste micronutriente foi evidenciada pela sua participação no sistema de proteção antioxidante, justificada pela incorporação de Se na glutationa peroxidase (E. C. 1.11.1.9). Esta enzima catalisa a redução de hidroperóxidos e facilita a conversão de H2O2, protegendo o organismo contra o dano oxidativo, e outros efeitos prejudiciais das espécies reativas de oxigênio (ROS). A atividade física proporciona um aumento no consumo de O2 e consequentemente maior produção de ROS, provocando estresse oxidativo. A pesquisa foi composta por 29 capoeiristas, residentes em São Paulo, com idade média de 21 anos para mulheres, e 24 para homens. O período médio de treinamento foi de 3,51 por semana e a duração de cada treinamento em média, foi de 109 minutes. O consumo médio de oxigênio (VO2 Máx.) foi de 41 ml/kg/min para as mulheres, e 48mllkg/min para os homens. A classificação do estado nutricional dos capoeiristas, de acordo com seu IMC foi normal (Organização Mundial de Saúde, 1995). Antes da suplementação, a ingestão usual de Se dos capoeiristas foi insatisfatória de acordo com a EAR e RDA. A concentração de Se no plasma e eritrócito aumentou depois da suplementação com CS (p<0,05), mas não houve correlação com o sexo dos participantes. A atividade enzimática da GPx também aumentou após a suplementação (p<0,05), demonstrando que a enzima é um sensível indicador do estado nutricional de Se, e não houve correlação em relação ao sexo dos participantes. Os resultados sugerem uma correlação positiva entre o efeito da suplementacão com CS e a concentração de Se e da atividade da enzima GPx (p< 0,05; R=0,72 para o plasma and R=85 para o eritrócito). / The purpose of this study was to establish a correlation between the effect of supplementation with Brazilian nuts (BN) with the nutritional status of Se and it\'s activity in young adult capoeira players. The biological importance of this oligoelement was evident by the participation in the \"antioxidant protection system\". It\'s antioxidant role is justified by its incorporation, as selenium, in the peroxidase glutathione (E.C. 1.11.1.9). This enzyme catalyzes the reduction of organic hidroperoxides and facilitates the conversion of H2O2 protecting the organism against the oxidative damage, and other harmful effects of \"reactive oxygen species\" (ROS). The physical activity causes an increase in consumption of O2 and consequently high production of ROS, causing oxidative stress. The population has composed of 29 capoeira players resident in São Paulo, with a mean age of 21 women and 24 for men. The average training period was 3,51 per week and the duration of each training period was 109,46 minutes. The average oxygen consumption (VO2 Máx., ml/kg/min) was 41 for women and 48 for men. Nutritional status classification of the capoeira players (cap) according with World Health Organization (WHO): IMC (1995) was normal. Before supplementation the usual diet was unsatisfactory for selenium according to EAR and RDA (2000). The Se concentration of the plasma and erythrocyte increased after supplementation with Brazilian nuts (p< 0,05), but didn\'t correlated with the sex of the participants. GSH-Px enzymatic activity also increased after this supplementation (p< 0,05), showing that this enzyme is a sensitive marker of nutritional status of Se. Also we didn\'t found correlation with the sex of the participants. The results suggest a positive correlation between the effect of supplementation with BN and Se concentrations and the activity of the GSH-Px enzyme (p< 0,05; R=0,72 for the plasma and R=85 for the erythrocyte).

O objetivo deste estudo foi estabelecer uma correlação entre o efeito da suplementação por meio da ingestão de castanhas-do-brasil (CS) com o estado nutricional de praticantes de capoeira em relação ao selênio (Se). A importância deste micronutriente foi evidenciada pela sua participação no sistema de proteção antioxidante, justificada pela incorporação de Se na glutationa peroxidase (E. C. 1.11.1.9). Esta enzima catalisa a redução de hidroperóxidos e facilita a conversão de H2O2, protegendo o organismo contra o dano oxidativo, e outros efeitos prejudiciais das espécies reativas de oxigênio (ROS). A atividade física proporciona um aumento no consumo de O2 e consequentemente maior produção de ROS, provocando estresse oxidativo. A pesquisa foi composta por 29 capoeiristas, residentes em São Paulo, com idade média de 21 anos para mulheres, e 24 para homens. O período médio de treinamento foi de 3,51 por semana e a duração de cada treinamento em média, foi de 109 minutes. O consumo médio de oxigênio (VO2 Máx.) foi de 41 ml/kg/min para as mulheres, e 48mllkg/min para os homens. A classificação do estado nutricional dos capoeiristas, de acordo com seu IMC foi normal (Organização Mundial de Saúde, 1995). Antes da suplementação, a ingestão usual de Se dos capoeiristas foi insatisfatória de acordo com a EAR e RDA. A concentração de Se no plasma e eritrócito aumentou depois da suplementação com CS (p<0,05), mas não houve correlação com o sexo dos participantes. A atividade enzimática da GPx também aumentou após a suplementação (p<0,05), demonstrando que a enzima é um sensível indicador do estado nutricional de Se, e não houve correlação em relação ao sexo dos participantes. Os resultados sugerem uma correlação positiva entre o efeito da suplementacão com CS e a concentração de Se e da atividade da enzima GPx (p< 0,05; R=0,72 para o plasma and R=85 para o eritrócito). / The purpose of this study was to establish a correlation between the effect of supplementation with Brazilian nuts (BN) with the nutritional status of Se and it\'s activity in young adult capoeira players. The biological importance of this oligoelement was evident by the participation in the \"antioxidant protection system\". It\'s antioxidant role is justified by its incorporation, as selenium, in the peroxidase glutathione (E.C. 1.11.1.9). This enzyme catalyzes the reduction of organic hidroperoxides and facilitates the conversion of H2O2 protecting the organism against the oxidative damage, and other harmful effects of \"reactive oxygen species\" (ROS). The physical activity causes an increase in consumption of O2 and consequently high production of ROS, causing oxidative stress. The population has composed of 29 capoeira players resident in São Paulo, with a mean age of 21 women and 24 for men. The average training period was 3,51 per week and the duration of each training period was 109,46 minutes. The average oxygen consumption (VO2 Máx., ml/kg/min) was 41 for women and 48 for men. Nutritional status classification of the capoeira players (cap) according with World Health Organization (WHO): IMC (1995) was normal. Before supplementation the usual diet was unsatisfactory for selenium according to EAR and RDA (2000). The Se concentration of the plasma and erythrocyte increased after supplementation with Brazilian nuts (p< 0,05), but didn\'t correlated with the sex of the participants. GSH-Px enzymatic activity also increased after this supplementation (p< 0,05), showing that this enzyme is a sensitive marker of nutritional status of Se. Also we didn\'t found correlation with the sex of the participants. The results suggest a positive correlation between the effect of supplementation with BN and Se concentrations and the activity of the GSH-Px enzyme (p< 0,05; R=0,72 for the plasma and R=85 for the erythrocyte).

Indiana University-Purdue University Indianapolis (IUPUI) / Signal Transducer and Activator of Transcription 3 (STAT3) is known to be related to bone metabolism. Mutation of STAT3 causes a rare disorder in which serum levels of IgE are elevated. This causes various skeletal problems similar to osteoporosis. To examine the effect of STAT3 in the osteoclast, we obtained two osteoclast specific STAT3 knockout mouse models: one using the CTSK promoter to drive Cre recombinase and another using a TRAP promoter. Examination of these mice at 8 weeks of age revealed a decreased trabecular bone volume in CTSK specific STAT3 knockout mice along with a slight decrease in osteoclast number in both CTSK and TRAP specific STAT3 knockout females. We also noticed changes in bone mineral density and bone mechanical strength in females. These data suggest that STAT3 plays a part in the function of the osteoclast.