Studies concerning the development of the magnocellular system are scarce and discordant in literature. We carried out an immunohistochemical study on supraotic and paraventricular hypothalamic nuclei using antivasopressin and antioxytocin antibodies in developing rats between the 15th day of intrauterine life and the 6th day of postnatal life. In addition, we performed RT-PCR experiments to establish the stage at which these hormones appear and neurosecretory activity commences. The results showed that supraoptic and paraventricular nuclei appear, respectively, on the 16th and the 18th day of intrauterine life and both immediately synthetize vasopressin neurohormone. By contrast, synthesis of oxytocin takes place from the 2nd day after birth. Probably, these nuclei synthetize oxytocin in conjunction with the decline of placental maternal oxytocin

Simultaneous exposure to contrast administration and pulse-inversion harmonic imaging with a high mechanical index causes ultrastructural damage in the rabbit liver.

In this work, we showed the presence of atrial natriuretic factor (ANF) in human prostate and compared its localisation in normal and hyperplastic conditions. ANF was localised in epithelial and stromal cells, being increased in hyperplasia, mainly in the stromal component. Moreover, we compared ANF and oxytocin positivity in the same glands, focusing on the possible relationship between the paracrine effects of these two hormones.

Since a relationship between atrial natriuretic peptide and oxytocin was recently demonstrated in the heart (Gutkowska et al., 1997), the aim of this study was to determine whether a relationship between the two peptides is present also in the rat hypothalamus. For this purpose, we measured ANPontogeny in the rat hypothalamus immunohistochemically and compared it with oxytocin-ontogeny which we previously studied. The results showed that the ANP-peptide and mRNA-ANP start at the 18th day of the fetal life. Our earlier data for oxytocin in the rat hypothalamus showed that only mRNA-oxytocin appeared the 18th day of foetal life (Farina Lipari et al., 2001); thus, at the 18th day of foetal life, mRNA-ANP, ANP-peptide and mRNA-oxytocin are present.We conclude that in the hypothalamus, differently from that in the heart, ANP might play a role on the synthesis of the oxytocin since ANP and its mRNA appear earlier than oxytocin

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