Percorrer por autor "Monteiro, Pedro Ribeiro Rocha"
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- Can lycopene be considered an effective protection against cardiovascular disease?Publication . Rodrigues, João Costa; Pinho, O.; Monteiro, Pedro Ribeiro Rocha; Costa-Rodrigues, Joao; Monteiro, PedroLycopene is a bioactive component mainly found in tomato. It is characterized by a high antioxidant potential, the highest among carotenoids. Mainly due to this property, lycopene has been suggested to display many beneficial effects, including its potential cardioprotective role. Despite some contradictory observations, which appear to be mainly caused by discrepancies in the different experimental protocols applied in the different studies, growing evidence points to clear benefits of lycopene in the maintenance of cardiovascular function and health. The knowledge about lycopene’s preventive effects in atherosclerosis, and other cardiovascular diseases, must be translated into changes in food patterns, aiming to increase the consumption of tomato, tomato-containing products, or other foods with high lycopene content, which can have an important impact on cardiovascular disease, particularly in countries where this represents a major public health concern.
- In vitro metabolism of steroid hormones by ovary and hepatopancreas of the crustacean Penaeid shrimp Marsupenaeus japonicusPublication . Summavielle, Teresa; Monteiro, Pedro Ribeiro Rocha; Reis-Henriques, Maria Armanda; Coimbra, João; Monteiro, Pedro; Summavielle, TeresaRadioimmunoassay (RIA) was applied to identify selected metabolites obtained in in vitroincubations of ovarianand hepatopancreatic tissues from female Marsupenaeus japonicusin previtellogenic and vitellogenic maturation stages. Depend-ing on the precursors used, progesterone, 17α-hydroxyprogesterone or testosterone, it was possible to observe the presence of sev-eral enzymatic activities through metabolites detected in incubations. The present study provides evidence that the ovary of theshrimpM. japonicusis capable of synthesising 17β-estradiol from progesterone, evidencing the presence of 17α-hydroxy-lase, C17-C20lyase, 17β-hydroxysteroid dehydrogenase (17β-HSD) and aromatase. Enzymatic activities of aromatase, 3β-HSD and 17α-hydroxylase were detected in hepatopancreas, but not that of C17-C20lyase. These results suggest that 17β-estradiol could be the vitellogenesis stimulating ovarian hormone (VSOH), and together with former in vivoand in vitrostudies this leads us to propose that in fact there may be a physiological role for steroid hormones in the maturation cycleof crustaceans.