Browsing by Subject "Pinealocyte"

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    Cell proliferation in the developing rat pineal gland.A bromodeoxyuridine immunohistochemical study
    (Murcia : F. Hernández, 2000) Calvo, J.L.; Boya, J.; Carbonell, A.L.; García-Mauriño, J.E.
    The immunohistochemical detection of bromodeoxyuridine (BrdU) was used to study the cell proliferation in the developing rat pineal gland, from the appearance of pineal primordium in the embryonic day 15 (E15) until 30 days after birth. The results showed three different proliferative phases. From E15 to E21, the pineal gland shows a phase of rapid proliferation. The second phase corresponds to the first postnatal week, in which the number of labeled cells per surface unit decreases suddenly to values between 20% to 10% of those of embryonic period. From the second postnatal week onwards, the number of BrdU-positive cells progressively decreases.
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    Postnatal maturation of the parenchymal cell types in the rabbit pineal gland
    (Murcia : F. Hernández, 1992) García-Mauriño, J.E.; Boya, J.
    An ultrastructural study on the maturation of the parenchymal rabbit pineal cell types from the first postnatal day up to 120 days is presented. Two main cell types are distinguished from the first 24h of postnatal life. Pinealocytes of the types 1 and 11 display different developmental degrees. Both immature cell types are arranged in groups. In addition, type 11 pinealocytes form rosette-like structures. Both cell types progressively become isolated and display cell processes. The nucleus and the cytoplasm of type 1 pinealocytes are barely electrondense. During the postnatal period, the number of cytoplasmic organelles, cell processes and terminal clubs increase progressively. Terminal clubs are frequently seen near blood vessels. After 30 days, type 1 pinealocytes show characteristics of adult pinealocytes. However, the maturation of rnost type 1 pinealocytes does not complete until the 90th postnatal day. Type 11 pinealocytes present a fairly electrondense nucleus and cytoplasm. Mature forms can be seen after the 5th postnatal day. During the postnatal period, a close relationship is determined arnong type 11 pinealocytes and cell processes and terminal clubs of type 1 pinealocytes.
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    Ultrastructural changes in the rat pineal gland after sympathetic denervation. Quantitative study
    (Murcia : F. Hernández, 1990) Calvo, J.L.; Boya, J.; García-Mauriño, J.E.
    Ultrastructural changes in the rat pineal gland were studied quantitatively 7 and 60 days after the sympathetic denervation by bilateral excission or decentralization of superior cervical ganglia. The surface occupied by pineal parenchymal cells decreased in rats of experimental groups with respect to the control group. Furthermore, profile areas of the cytoplasm, nucleus and nucleolus of the pinealocytes were also diminished. Cytoplasmic lipid droplets in the pinealocytes were markedly decreased in number and size in experimental rats. As demonstrated by the Kruskal-Wallis H test, statistically significant differences were found between rats of the control and operated groups. Rats treated by superior cervical ganglionectomy or decentralization showed morphological changes indicating a hypofunctional pineal gland, although differences were found between both groups.