Linked Life Data

12403848

Source:http://linkedlifedata.com/resource/pubmed/id/12403848

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2002-10-29
pubmed:abstractText
Steroid hormones induce rapid membrane receptor-mediated effects that appear to be separate from long-term genomic events. The membrane receptor-mediated effects of androgens on GT1-7 GnRH-secreting neurons were examined. We observed androgen binding activity with a cell-impermeable BSA-conjugated testosterone [testosterone 3-(O-carboxymethyl)oxime (T-3-BSA)] and were able to detect a 110-kDa protein recognized by the androgen receptor (AR) monoclonal MA1-150 antibody in the plasma membrane fraction of the GT1-7 cells by Western analysis. Further, a transfected green fluorescent protein-tagged AR translocates and colocalizes to the plasma membrane of the GT1-7 neuron. Treatment with 10 nM 5alpha-dihydrotestosterone (DHT) inhibits forskolin-stimulated accumulation of cAMP, through a pertussis toxin-sensitive G protein, but has no effect on basal cAMP levels. The inhibition of forskolin-stimulated cAMP accumulation by DHT was blocked by hydroxyflutamide, a specific inhibitor of the nuclear AR. DHT, testosterone (T), and T-3-BSA, all caused significant elevations in intracellular calcium concentrations ([Ca(2+)](i)). T-3-BSA stimulates GnRH secretion 2-fold in the GT1-7 neuron, as did DHT or T. Interestingly GnRH mRNA levels were down-regulated by DHT and T as has been reported, but not by treatment with T-3-BSA or testosterone 17beta-hemisuccinate BSA. These studies indicate that androgen can differentially regulate GnRH secretion and gene expression through specific membrane-mediated or nuclear mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2592-602
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Differential regulation of gonadotropin-releasing hormone secretion and gene expression by androgen: membrane versus nuclear receptor activation.
pubmed:affiliation
Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't