Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-07T13:03:20Z No. of bitstreams: 1 TatianeGomesTeixeiraTese2014.pdf: 4120392 bytes, checksum: 476b0dc4161238fdb83458fa4a8e820d (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-07T13:03:30Z (GMT) No. of bitstreams: 1 TatianeGomesTeixeiraTese2014.pdf: 4120392 bytes, checksum: 476b0dc4161238fdb83458fa4a8e820d (MD5) / Made available in DSpace on 2017-04-07T13:03:30Z (GMT). No. of bitstreams: 1 TatianeGomesTeixeiraTese2014.pdf: 4120392 bytes, checksum: 476b0dc4161238fdb83458fa4a8e820d (MD5) Previous issue date: 2014-12-03 / Reduced nitric oxide (NO) bioavailability is involved in a number of cardiovascular, muscular and inflammatory mechanisms, mainly in the elderly; while physical exercise has been pointed as an important tool in preventing and minimizing the negative effects of aging. The present thesis comprises two studies that aimed 1) To investigate the influence of the endothelial nitric oxide synthase (eNOS) polimorphysm (Glu298Asp) on the acute response of NO to eccentric resistance exercise (ERE), and also on the biochemical markers, body composition and muscular strength of obese elderly women. 2) To identify the presence of subjects with low or high responsivity of NO to ERE, and the influence of distinct levels of responsivity on biochemical and inflammatory markers, body composition and muscular strength. Eighty-seven older women (69.4 ?? 6.1 years, 74.9 ?? 12.7 kg, heigh 151.9 ?? 6.0 cm and BMI 32.5 ?? 5.7 kg/m2) participated in the study. Forty-nine of them participated of the second study. The exercise protocol consisted of seven sets of ten eccentric repetitions at 110% of ten repetitions maximum (10RM) and the serum concentration of nitrite was measured immediately after and 3, 24 and 48 hours after the ERE. Results: The ERE elevated the serum concentration of nitrite, without a significative influence of eNOS polymorphism (study 1). The group of T allele carriers (TT or TG genotype) presented higher triglicerides (p=0.014), VLDL (p=0.025) and urea (p=0.038) concentrations, and lower body weight (p=0.013), BMI (p=0.031), prevalence of obesity (81% versus 56%) and relative muscle strength (p=0.047) as compared with the GG genotype carriers. Inter-individual differences were found in the magnitude of serum response of nitrite to ERE, which allowed the identification of low (LR) and high responsive (HR) groups (study 2). The LR group presented higher percentual body fat (p=0.017), total cholesterol (p=0.043) and LDL (p=0.044), and lower upper limb fat-free mass (p=0.054) as compared with the HR group. These results demonstrate that: a) in obese older women, nitrite concentration is elevated up to 48 h after ERE, and the magnitude is influenced by inter-individual variations, independently of eNOS polymorphism; b) the presence of the eNOS polymorphism Glu298Asp (TT or TG genotype) and the low responsivity of nitrite to ERE are indicative of unhealthier lipid profile and higher fat percentage in older obese women. Furthermore, these parameters can be used in clinical practice to improve the identification of the impairment degree during aging, as well for understanding the different responses to exercise. / A redu????o da biodisponibilidade de ??xido n??trico (NO) est?? envolvida em in??meros mecanismos cardiovasculares, musculares e inflamat??rios, principalmente na popula????o idosa; enquanto o exerc??cio f??sico tem sido apontado como importante estrat??gia para prevenir e minimizar os efeitos delet??rios do envelhecimento. A presente tese ?? composta por dois estudos quantitativos, de delineamento quaseexperimental, que objetivaram 1) Investigar a influ??ncia do polimorfismo (Glu298Asp) da ??xido n??trico sintase endotelial (eNOS) sobre a resposta aguda do NO ao exerc??cio de for??a exc??ntrico (EFE), bem como sobre os marcadores bioqu??micos, a composi????o corporal e a for??a muscular de idosas obesas; 2) Identificar a presen??a de idosas com alta ou baixa responsividade do NO ao EFE, e a influ??ncia dos distintos graus de responsividade sobre os marcadores bioqu??micos, inflamat??rios, composi????o corporal e for??a muscular. Participaram do primeiro estudo 87 idosas (69,4 ?? 6,1 anos, 74,9 ?? 12,7 kg, estatura 151,9 ?? 6,0 cm e IMC 32,5 ?? 5,7 kg/m2), 49 das quais compuseram a amostra do segundo estudo. As volunt??rias completaram sete s??ries de 10 repeti????es exc??ntricas a 110% de 10 repeti????es m??ximas (10RM), sendo a concentra????o s??rica de nitrito medida imediatamente ap??s e 3, 24 e 48 horas ap??s o EFE. Resultados: o EFE provocou eleva????o da concentra????o de nitrito, sem influ??ncia significativa do polimorfismo da eNOS (estudo 1). As carreadoras do alelo T apresentaram maior concentra????o de triglicer??deos (p=0,014), VLDL (p=0,025) e ureia (p=0,038), e menor peso corporal total (p=0,013), IMC (p=0,031), preval??ncia de obesidade (81% versus 56%) e for??a muscular relativa (p=0,047) em compara????o ??s idosas com gen??tipo GG. Foram encontradas diferen??as interindividuais na magnitude de aumento do nitrito p??s-EFE, o que permitiu a identifica????o de grupos pouco (PR) e muito responsivos (MR) (estudo 2). Idosas PR apresentaram maior percentual de gordura (p=0,017), colesterol total (p=0,043) e LDL (p=0,044), e menor massa livre de gordura de membros superiores (p=0,045) em compara????o ??s MR (estudo 2). Estes resultados demonstram que: a) a concentra????o de nitrito em idosas obesas se eleva at?? 48 horas ap??s o EFE, sendo a magnitude influenciada por varia????es inter-individuais, independentemente do polimorfismo da eNOS; b) a presen??a do polimorfismo Glu298Asp eNOS (gen??tipo TT ou TG) e a baixa responsividade do nitrito ao EFE s??o indicativos de piores perfil lip??dico e percentual de gordura corporal em idosas obesas. Sendo assim, estes par??metros podem ser utilizados na pr??tica cl??nica para melhorar a identifica????o do grau de acometimento durante o envelhecimento, bem como para entendimento das diferentes respostas ao exerc??cio.