Secretion of hypothalamic dopamine into pituitary stalk blood of aged female rats

Détails

ID Serval
serval:BIB_6977DCC37A60
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Secretion of hypothalamic dopamine into pituitary stalk blood of aged female rats
Périodique
Brain Research Bulletin
Auteur(s)
Reymond  M. J., Porter  J. C.
ISSN
0361-9230
Statut éditorial
Publié
Date de publication
07/1981
Peer-reviewed
Oui
Volume
7
Numéro
1
Pages
69-73
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Jul
Résumé
Dopamine secreted into the pituitary stalk blood of old constant estrous rats (20-24 months of age) was significantly less than that of young estrous rats (3-4 months of age). Reduced concentrations of dopamine were also observed in the median eminence and in the neurointermediate lobe of the pituitary gland of old female rats compared to those of young female rats. The low rate of secretion of dopamine into pituitary stalk blood of old female rats was associated with high secretion of prolactin into arterial blood. The impaired hypothalamic secretion of dopamine observed in old rats was not affected by increased availability of L-tyrosine. However, when L-DOPA was given to old rats, very high concentrations of dopamine were measured in pituitary stalk blood, whereas the concentrations of dopamine in the arterial blood were very low. On the basis of these data, it is concluded that the neurosecretory activity of the dopaminergic neurons of the hypothalamus is impaired in old constant estrous rats. This impaired activity can be overcome by increasing the availability of L-DOPA but not L-tyrosine.
Mots-clé
*Aging/drug effects Animals Dopamine/*blood Estrus/drug effects Female Hypothalamus/*secretion Levodopa/pharmacology Median Eminence/metabolism Pituitary Gland/*blood supply Pregnancy Prolactin/blood Rats Tyrosine/pharmacology
Pubmed
Web of science
Création de la notice
11/02/2008 15:11
Dernière modification de la notice
20/08/2019 15:24
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