Browsing by Subject "Corticosterone"

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    Argentic staining reveals changes in cerebellar tissue organisation by prenatal glucocorticoid administration in rats
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Rivas-Manzano, Patricia; Ramírez-Escoto, María Marcela; De la Rosa-Rugerio, Concepción; Rugerio-Vargas, Concepción; Ortiz-Hernández, Rosario; Torres-Ramírez, Nayeli
    It was almost 150 years ago that Golgi revolutionised histology with silver-based stains. Major advances in knowledge of the nervous system became possible because of silver impregnations. Silver staining combined with classical histological staining, cytochemistry methods, and electron microscopy is useful for studying mechanisms and components at subcellular, cellular, and tissue levels. Despite the advantages of silver staining, its use has decreased over time. The aim of this work was to use argentic staining to study the cerebellar effects of controversial prenatal glucocorticoid (GC) therapy. At postnatal day 12 (P12), the cerebellum of corticosterone (CC)-treated rats impregnated with AgNOR staining exhibited diminished thickness of the external granule layer (EGL) and irregular Purkinje cell arrangement. There was a greater number of nucleoli and nucleolar organiser regions (NORs) in 24% of Purkinje cells. Cerebellar granule neuron progenitor (CGNP) cells of the EGL showed a decrease in cellular density (confirmed by proliferating cell nuclear antigen [PCNA] immunolocalization) and NORs. At postnatal day 6 (P6), the Golgi-Kopsch technique allowed us to observe disturbances in the distribution pattern of CGNP cells (during proliferation, migration, and differentiation) and premature growth of the Bergmann glia. Our findings reveal disturbances in the cerebellar development program with early cellular and tissue changes.
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    lmmunohistochemical analysis of adrenal proliferation and corticosterone expression in experimental adrenal regeneration
    (Murcia : F. Hernández, 1995) Sarría, R.; Losada, J.; Bueno-López, J.L.
    The proliferative activity, the organization and the corticosterone expression of adrenocortical cells in an experimental adrenal regeneration process after the transplantation of neonatal adrenal glands to adult hosts was investigated. Three days after transplantation, the medullar and the innermost adrenocortical cells of the neonatal adrenal glands showed degenerative and necrotic changes due to the lack of vascular supply. The remaining outermost adrenocortical cells did not display any PCNA immunoreaction. The first PCNA expression, pointing out the beginning of the proliferative cycle, was observed in a 45.4% of the adrenocortical cells, one week after transplantation. After three weeks, severa1 regenerated adrenocortical nodules with a bigger size than the one observed in the previous periods were seen. In these nodules, while the outermost adrenocortical cells were disposed in parallel to the capsule or in rounded groups, the bulk of the regenerated mass width was composed of cells forming longitudinal cords. PCNA immunoreaction was almost exclusively restricted to subcapsular cells (62.5%) and to cells of the outermost portion of the cords (32.5%), the global percentage of PCNA immunopositive cells being 18.4%. Twelve weeks after transplantation, regenerated adrenocortical cells were arranged in three layers: glomerulosa, fasciculata and reticularis. Only 1.85% of the adrenocortical cells were PCNA immunopositive. Although in the early stages of the regeneration process, al1 the adrenocortical cells, both proliferating and non proliferating cells expressed corticosterone, a restriction of this immunoreactivity to the zonae fasciculata and reticularis was observed when cell zonation was apparent.
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    Morphometric evidence of the regulation of the activity of LH-immunoreactive cells by corticosterone. An in vivo and in vitro study
    (Murcia : F. Hernández, 1996) Rubio, M.; Carretero, J.; Cabo, J.J.; Santos, M.; Vázquez, R.J.; Vázquez, R.; Sánchez, F.
    The present study was performed to investigate the morphometric effects of the administration of corticosterone on LH-immunoreactive cells of pituitary monolayer cultures. In addition, the effect of bilateral adrenalectomy on the LH-adenohypophyseal cells was explored. In vitro administration of corticosterone induced a marked decrease in the morphometric parameters considered (cellular, cytoplasmic and nuclear areas). In vivo, bilateral adrenalectomy produced a significant increase in these parameters when compared to those obtained in normal and sham-operated animals. However, when the bilaterally adrenalectomized rats received a daily dose of corticosterone no significant changes in the morphometric parameters were found. Morphometrically, these combined in vivo-in vitro findings confirm a corticosterone-induced hypoactivity of LI4-cells together with a direct effect of this glucocorticoid on LH-adenohypophyseal cells.