Aversive stimulation during the stress-hyporesponsive period does not affect the number of corticotroph cells in neonatal male rats.
Braz J Med Biol Res
; 30(12): 1463-6, 1997 Dec.
Article
em En
| MEDLINE
| ID: mdl-9686167
Immunohistochemistry was used to evaluate the effects of neonatal handling and aversive stimulation during the first 10 days of life on the number of corticotrophs in the anterior lobe of the pituitary of 11-day-old male Wistar rats. Since adult rats handled during infancy respond with reduced corticosterone secretion in response to stressors and with less behavior inhibition in novel environments, we assumed that neonatal stimulation could affect pituitary morphology during this critical period of cell differentiation. Three groups of animals were studied: intact (no manipulation, N = 5), handled (N = 5) and stimulated (submitted to 3 different aversive stimuli, N = 5). The percentage of ACTH-immunoreactive cells in the anterior lobe of the pituitary (number of ACTH-stained cells divided by total number of cells) was determined by examining three slices per pituitary in which a minimum of 200 cells were counted by two independent researchers. Although animals during the neonatal period are less reactive to stress-like stimulation in terms of ACTH and corticosterone secretion, results showed that the relative number of ACTH-stained cells of neonatal handled (0.25 +/- 0.01) and aversive stimulated (0.29 +/- 0.03) rats was not significantly different from intact (0.30 +/- 0.03) animals. Neonatal stimulation may have a differential effect on the various subpopulations of corticotroph cells in the anterior pituitary.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hipófise
/
Terapia Aversiva
/
Estresse Fisiológico
/
Hormônio Adrenocorticotrópico
/
Manobra Psicológica
Limite:
Animals
Idioma:
En
Revista:
Braz J Med Biol Res
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil