Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats

The aim of the present study was to determine the role of the endogenous sex steroid environment in the hypothalamo-corticotrope (HC) function in both sham-operated (SHAM) and bilaterally adrenalectomized (ADX) rats. For this purpose adult rats of both sexes were used 3 and 6 weeks after either SHAM...

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Autores principales: Chisari, Andrea Nancy, Perone, M. J., Giovambattista, Andrés, Spinedi, Eduardo Julio
Formato: Articulo
Lenguaje:Inglés
Publicado: 1998
Materias:
Ciencias Médicas
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/146619
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-146619
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Médicas
spellingShingle Ciencias Médicas
Chisari, Andrea Nancy
Perone, M. J.
Giovambattista, Andrés
Spinedi, Eduardo Julio
Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
topic_facet Ciencias Médicas
description The aim of the present study was to determine the role of the endogenous sex steroid environment in the hypothalamo-corticotrope (HC) function in both sham-operated (SHAM) and bilaterally adrenalectomized (ADX) rats. For this purpose adult rats of both sexes were used 3 and 6 weeks after either SHAM or ADX. The results indicate that: a) in SHAM animals, basal plasma ACTH levels were significantly higher in females than in males, and this sexual dimorphism was overridden by ADX, regardless of the time post-surgery; b) although basal anterior pituitary (AP) ACTH content was similar in SHAM animals of both sexes, 3- and 6-week ADX induced higher AP ACTH in males than in females; c) at 3- and 6-weeks, ADX rats of hoth sexes had an AVP: CRH ratio (r), in the median eminence (ME) and medial basal hypothalamus (MBH), increased several fold over the respective SHAM-value and, although no sexual dimorphism was found at week 3 post-ADX, by 6-weeks post ADX, these ratios were significantly higher in both brain tissues of females than in those of males; and d) the in vitro ME CRH and AVP output in response to high potassium concentrations (hK+; 28 and 56 mmol/l), was concentration-related, regardless of sex and surgery, and was characterized by enhanced secretion of neuropeptides by MEs from ADX in comparison to SHAM rats of both sexes, and a sexual dimorphism was found in this parameter, consisting in general, in greater neuropeptide output from tissues of female than of male animals. Our results indicate that: 1) there is a gender-dependent characteristic of the HC axis function in glucocorticoid-replete rats and 2) the absence of the glucocorticoid negative feedback mechanism is responsible for either the expression or for the override of the sexual dimorphism in different parameters, a phenomenon which dependent on the time elapsed after ADX.
format Articulo
Articulo
author Chisari, Andrea Nancy
Perone, M. J.
Giovambattista, Andrés
Spinedi, Eduardo Julio
author_facet Chisari, Andrea Nancy
Perone, M. J.
Giovambattista, Andrés
Spinedi, Eduardo Julio
author_sort Chisari, Andrea Nancy
title Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
title_short Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
title_full Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
title_fullStr Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
title_full_unstemmed Gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
title_sort gender-dependent characteristics of the hypothalamo-corticotrope axis function in glucocorticoid-replete and glucocorticoid-depleted rats
publishDate 1998
url http://sedici.unlp.edu.ar/handle/10915/146619
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AT giovambattistaandres genderdependentcharacteristicsofthehypothalamocorticotropeaxisfunctioninglucocorticoidrepleteandglucocorticoiddepletedrats
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