Thyroid hormones are involved in 5 '-nucleotidase modulation in soluble fraction of cardiac tissue

Aims: To investigate the role of TH (thyroid hormones) in 5'-nucleotidase activity and expression in cardiac soluble fraction (SF). Main methods: Male Wistar rats received daily injections of 14 (10, 25 or 50 mu g T4/100 g body weight) for 14 days to develop a hyperthyroidism condition. Thyroidectomy was performed in other animals to mimic hypothyroidism, and 14 days after surgery they were submitted to TH replacement therapy. Key findings: T4 reduced the 5'-nucleotidase activity (T4-25. P<0.05 and 14-50, P<0.01) in the SF. Conversely, hypothyroidism significantly increased the 5'-nucleotidase activity in this fraction (P<0.001) and TH replacement therapy reversed the latter result (P<0.001 compared to hypothyroid group). The analysis of protein expression in the SF showed that 5'-nucleotidase was more expressed in hypothyroid than in the control group and that the phosphorylated state of PKC observed in this condition may contribute to a possible mechanism of 5'-nucleotidase modulation by thyroid status. Significance: Taken together, these data reveal that TH can influence adenosine production by modulating 5'-nucleotidase activity and expression, which may contribute to the cardioprotective effect and the maintenance of cardiac function under TH privation. (C) 2012 Elsevier Inc. All rights reserved.

The effects of long-term endurance training on the immune and endocrine systems of elderly men: the role of cytokines and anabolic hormones

Abstract Background a decline in immune and endocrine function occurs with aging. The main purpose of this study was to investigate the impact of long-term endurance training on the immune and endocrine system of elderly men. The possible interaction between these systems was also analysed. Results elderly runners showed a significantly higher T cell proliferative response and IL-2 production than sedentary elderly controls. IL-2 production was similar to that in young adults. Their serum IL-6 levels were significantly lower than their sedentary peers. They also showed significantly lower IL-3 production in comparison to sedentary elderly subjects but similar to the youngs. Anabolic hormone levels did not differ between elderly groups and no clear correlation was found between hormones and cytokine levels. Conclusion highly conditioned elderly men seem to have relatively better preserved immune system than the sedentary elderly men. Long-term endurance training has the potential to decelerate the age-related decline in immune function but not the deterioration in endocrine function.

Elaboração de tabelas de percentis através de parâmetros antropométricos, de desempenho, bioquímicos, hematológicos, hormonais e psicológicos em futebolistas profissionais

INTRODUÇÃO: A carência de valores de referência de parâmetros antropométricos, de desempenho, bioquímicos, hematológicos, hormonais e psicológicos é uma limitação importante nas investigações envolvendo futebolistas profissionais. OBJETIVO: Elaborar tabelas de percentis para servirem como referencial de comparação para estudos posteriores. MÉTODOS: Foram utilizados 82 jogadores profissionais de futebol que foram avaliados aproximadamente 30 dias após o início da principal competição disputada pelas equipes. No primeiro dia de avaliação foram coletadas amostras de sangue (25mL) em jejum para determinação dos parâmetros hematológicos (eritrócitos, hemoglobina, hematócrito, volume corpuscular médio - VCM, hemoglobina corpuscular média - HCM, concentração de hemoglobina corpuscular média - CHCM, leucócitos, neutrófilos, eosinófilos, linfócitos, monócitos e plaquetas) e das concentrações de adrenalina, cortisol, creatina quinase, creatinina, noradrenalina, testosterona e ureia. Posteriormente, os atletas foram submetidos à avaliação antropométrica e psicológica. Em seguida, a avaliação da eficiência do sistema anaeróbio lático foi realizada em pista oficial de atletismo. No segundo dia foram realizadas as avaliações para determinação da eficiência do sistema anaeróbio alático e aeróbio. RESULTADOS: A distribuição de percentis (P0, P15, P30, P50, P70, P85 e P100) foi utilizada para apresentação dos resultados. CONCLUSÃO: A elaboração de tabelas de percentis pode ser utilizada como referencial de comparação para investigações posteriores.