Publications by authors named "Ivone Castro"
Background: The contraceptive effect of the progestogen norethisterone (NET) and its main metabolites 5alpha-NET and 3beta,5alpha-NET has been demonstrated in several species, and most studies have focused on the effects of these compounds in the uterus. We previously reported that 5alpha-NET inhibits the progesterone (P(4))-induced acrosome reaction in pig and mouse spermatozoa and induces severe morphological damage in two-cell fertilized mouse oocytes.
Study Design: The main goal of this study was to analyze the possible role of P(4) receptor (PR) in the effects of NET and 5alpha-NET on the oocyte fertilization process.
Background: Estrogens exert profound effects on target tissues. These effects are mediated by two estrogen receptors (ER(alpha) and ER(beta)) that bind to specific DNA sequences in estrogen-dependent genes. Other molecules such as growth factors, transcription factors and some oncoproteins might interact with the estrogen receptors and thus regulate the transcription of these genes.
View Article and Find Full Text PDFObjective: To investigate whether the serum prolactin (PRL) response to a dopamine antagonist was different in nonobese, euthyroid women with malignant or benign breast tumors in comparison with healthy women, considering their age at first full-term pregnancy or their nulliparity.
Methods: Serum PRL concentrations before and 60, 90, and 120 minutes after oral administration of metoclopramide (10 mg) were studied in 122 nonobese, nonsmoking, euthyroid women: 28 who had invasive breast cancer, stage I or II (group 1), 34 who had benign breast disease (group 2), and 60 who were clinically healthy (group 3). These three main groups were subdivided into early and late parous women (< or = 25 and >25 years, respectively) and nulliparous women, and the menopausal status was also considered.