Secretion of hypothalamic dopamine into pituitary stalk blood of aged female rats
Details
Serval ID
serval:BIB_6977DCC37A60
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Secretion of hypothalamic dopamine into pituitary stalk blood of aged female rats
Journal
Brain Research Bulletin
ISSN
0361-9230
Publication state
Published
Issued date
07/1981
Peer-reviewed
Oui
Volume
7
Number
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
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Jul
Abstract
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.
Keywords
*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
Create date
11/02/2008 15:11
Last modification date
20/08/2019 15:24