Immunolocalization of estrogen receptor alpha in adult female rat hippocampus / Inmunolocalización del receptor de estrógeno alfa en el hipocampo de rata hembra adulta

The present study was planned to demonstrate the detailed immunoreactive (IR) distribution pattern of estrogen receptors (ER) in hippocampus of 15 female rats, adult, female Wistar rats in estrous phase. 30 µm thick setions of hippocampal region fixed (4 percent buffered paraformaldehyde) were obtained with cryostat. The sections were processed free- floating for immunolocalization of ER using, mouse monoclonal anti-ER-a antibody with PAP technique. The results showed presence of ER immunoreactive neurons in all the subfields of hippocampus with some variations. In cornua ammonis (CA) maximum ER positive (+ve) neurons were localized in CA3 region. Layer analysis showed maximum localization in the stratum oriens (SO) region. In other subfields and layers of CA the IR neurons were comparatively less in number. The morphological characters of all ER +ve neurons showed them to be interneurons both in CA as well as in Dentate gyrus (DG).

El estudio fue diseñado para demostrar el patrón de distribución inmunorreactivo (IR) detallado de los receptores estrogénicos (RE) en el hipocampo de 15 ratas Wistar, hembras, adultas, en fase de estro. Fueron obtenidas secciones 30 µm de grosor con un crióstato, de la región del hipocampo fijadas por perfusión (4 por ciento de paraformaldehído tamponado). Las secciones fueron procesadas, por libre flotación, para la inmunolocalización de RE utilizando anticuerpo monoclonal de ratón anti-ER-a con la técnica de PAP. Los resultados mostraron la presencia de neuronas inmunorreactivas ER en todos los subcampos del hipocampo con algunas variaciones. En el cuerno ventral (CA) la mayor zona RE positiva (+ ve) de las neuronas se localizaron en la región CA3. El análisis de las capas mostró la localización máxima en la región del estrato oriens (SO). En otros subcampos y capas de la CA las neuronas IR fueron comparativamente menores en número. Las características morfológicas de todas las neuronas RE + ve resultaron ser interneuronas tanto en el CA como en el giro dentado (DG).

Differential binding with ERá and ERâ of the phytoestrogen-rich plant Pueraria mirifica

Variations in the estrogenic activity of the phytoestrogen-rich plant, Pueraria mirifica, were determined with yeast estrogen screen (YES) consisting of human estrogen receptors (hER) hERá and hERâ and human transcriptional intermediary factor 2 (hTIF2) or human steroid receptor coactivator 1 (hSRC1), respectively, together with the â-galactosidase expression cassette. Relative estrogenic potency was expressed by determining the â-galactosidase activity (EC50) of the tuber extracts in relation to 17â-estradiol. Twenty-four and 22 of the plant tuber ethanolic extracts interacted with hERá and hERâ, respectively, with a higher relative estrogenic potency with hERâ than with hERá. Antiestrogenic activity of the plant extracts was also determined by incubation of plant extracts with 17â-estradiol prior to YES assay. The plant extracts tested exhibited antiestrogenic activity. Both the estrogenic and the antiestrogenic activity of the tuber extracts were metabolically activated with the rat liver S9-fraction prior to the assay indicating the positive influence of liver enzymes. Correlation analysis between estrogenic potency and the five major isoflavonoid contents within the previously HPLC-analyzed tuberous samples namely puerarin, daidzin, genistin, daidzein, and genistein revealed a negative result.