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1.
J Physiol ; 588(Pt 13): 2431-42, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20442263

RESUMO

Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex). Echocardiography, haemodynamic measurements and isolated papillary muscle were used for functional evaluations. Real-time RT-PCR and Western blot were used to quantify tumour necrosis factor alpha, interleukin-6, interleukin-10 and transforming growth factor beta(1) (TGF-beta(1)) in the tissue. NF-B expression in the nucleus was evaluated by immunohistochemical staining. The Iso rats showed a concentric hypertrophy of the left ventricle (LV). These animals exhibited marked increases in LV end-diastolic pressure and impaired myocardial performance in vitro, with a reduction in the developed tension and maximal rate of tension increase and decrease, as well as worsened recruitment of the Frank-Starling mechanism. Both gene and protein levels of tumour necrosis factor alpha and interleukin-6, as well as TGF-beta(1) mRNA, were increased. In addition, the NF-B expression in the Iso group was significantly raised. In the Iso+Ex group, the exercise training had the following effects: (1) it prevented LV hypertrophy; (ii) it improved myocardial contractility; (3) it avoided the increase of proinflammatory cytokines and improved interleukin-10 levels; and (4) it attenuated the increase of TGF-beta(1) mRNA. Thus, exercise training in a model of beta-adrenergic hyperactivity can avoid the adverse remodelling of the LV and inhibit inflammatory cytokines. Moreover, the cardioprotection is related to beneficial effects on myocardial performance.


Assuntos
Cardiomiopatias/prevenção & controle , Cardiomiopatias/fisiopatologia , Citocinas/metabolismo , Condicionamento Físico Animal/fisiologia , Receptores Adrenérgicos beta/fisiologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Western Blotting , Cardiomegalia/induzido quimicamente , Cardiomegalia/fisiopatologia , Cardiomiopatias/induzido quimicamente , Cardiotônicos/farmacologia , Circulação Coronária/fisiologia , Ecocardiografia , Imuno-Histoquímica , Inflamação/metabolismo , Isoproterenol/farmacologia , Masculino , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , NF-kappa B/biossíntese , Ratos , Ratos Wistar , Receptores Adrenérgicos beta/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/metabolismo , Função Ventricular Esquerda/fisiologia
2.
Geriatr Gerontol Int ; 8(4): 265-71, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19149838

RESUMO

AIM: The effectiveness of a water-based exercise (WE) program and a walking on land (WL) program was evaluated in older women (aged 62-65 years). METHODS: Fifty healthy sedentary women were randomly assigned to sedentary (S), WE and WL groups. The two groups were exercised for 12 weeks at 70% of the age-predicted maximum heart rate (HR). The subjects were evaluated before and after the training period, and measurements of bodyweight, HR at rest, maximum aerobic power (VO(2max) mL/kg per min) and neuromuscular performance (upper and lower body strength; agility; upper and lower body flexibility) were included. RESULTS: After training, bodyweight was unchanged in both programs. The WE decreased the HR at rest by 10%. Both WE and WL enhanced VO(2max) by 42% and 32%, respectively. However, for the WE group the VO(2max) values were significantly higher compared with the WL group (P < 0.05). All neuromuscular parameters improved after exercise, but only the WE group showed a significant improvement on the upper body strength and lower body flexibility. Besides, the upper and lower body strength and upper and lower body flexibility were significantly higher in the WE group compared with the WL group (P < 0.05), respectively. CONCLUSIONS: Current results indicate that the WE and WL programs improved the cardiorespiratory and neuromuscular fitness of older women. Furthermore, when the effectiveness of the training programs were compared, it was verified that the WE program was more powerful in inducing changes in physical fitness versus the WL program.


Assuntos
Aptidão Física , Treinamento de Resistência , Caminhada , Idoso , Feminino , Frequência Cardíaca , Humanos , Pessoa de Meia-Idade , Força Muscular , Consumo de Oxigênio , Maleabilidade
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