Document Detail


Long-term treatment with estradiol induces reversible alterations in tuberoinfundibular dopaminergic neurons: a decreased responsiveness to prolactin.
MedLine Citation:
PMID:  6504266     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Previous studies have demonstrated that short-term (3-5 days) treatment with estradiol increases the rate of turnover and synthesis of dopamine (DA) in terminals of tuberoinfundibular (TI) neurons in the median eminence by virtue of the ability of this hormone to increase circulating concentrations of prolactin. The present studies were undertaken to examine the long-term effects of estradiol on serum prolactin concentrations and TIDA neuronal activity (estimated by the rate of DOPA accumulation in the median eminence after the administration of a decarboxylase inhibitor). Female rats, ovariectomized for 2 weeks, were implanted subcutaneously with silastic capsules containing estradiol benzoate and sacrificed 6, 12 and 18 days after capsule implantation. Serum prolactin concentrations were markedly increased at 6, 12 and 18 days whereas the rate of DOPA accumulation was increased at 6 days but not at 12 days, and was decreased at 18 days. The concentration of DA in the median eminence was reduced at 6 days and further reduced at 12 and 18 days. The low rate of DOPA accumulation in the median eminence despite the high circulating concentrations of prolactin suggests that long-term estradiol treatment reduces the ability of TIDA neurons to respond to prolactin. This was confirmed by the finding that direct intracerebroventricular (icv) injections of prolactin increased the rate of DOPA accumulation in the median eminence of sham-implanted rats but not in 18 day estradiol-treated rats. To determine if the effects of estradiol were reversible, ovariectomized rats were implanted with estradiol-containing capsules for 18 days.(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
K T Demarest; G D Riegle; K E Moore
Related Documents :
168606 - Effects of early post-natal alpha-methyl-dopa treatment on behavior in the rat.
7915606 - Neuroanatomical characterization of a new mutant rat with dopamine depletion in the sub...
17027936 - Subchronic administration of l-dopa to adult rats with a unilateral 6-hydroxydopamine l...
1922966 - Age-related changes in locomotor behavior induced by mptp in rats.
7340456 - The modulation of inflammation by the acute phase reaction in adjuvant arthritis in rats.
16278276 - Effects of sodium nitrite on ischemia-reperfusion injury in the rat kidney.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Neuroendocrinology     Volume:  39     ISSN:  0028-3835     ISO Abbreviation:  Neuroendocrinology     Publication Date:  1984 Sep 
Date Detail:
Created Date:  1985-01-04     Completed Date:  1985-01-04     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0035665     Medline TA:  Neuroendocrinology     Country:  SWITZERLAND    
Other Details:
Languages:  eng     Pagination:  193-200     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Dopamine / physiology*
Estradiol / pharmacology*
Female
Haloperidol / pharmacology
Hypothalamus / drug effects*
Neurons / drug effects*
Prolactin / blood,  physiology*
Rats
Rats, Inbred Strains
Time Factors
Grant Support
ID/Acronym/Agency:
AG02644/AG/NIA NIH HHS; NS09174/NS/NINDS NIH HHS
Chemical
Reg. No./Substance:
50-28-2/Estradiol; 52-86-8/Haloperidol; 9002-62-4/Prolactin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Calcified chronic subdural hematoma. A case report in an old patient
Next Document:  Endogenous prostaglandins affect growth hormone and thyrotropin release at a hypothalamic, not a pit...