Linked Life Data

8954765

Source:http://linkedlifedata.com/resource/pubmed/id/8954765

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-3-10
pubmed:abstractText
Treatment of mature female tilapia (Oreochromis niloticus) with high levels of androgen (17 alpha-methyltestosterone, 17 alpha MT) results in a pronounced decline in plasma vitellogenin levels as determined by gel electrophoresis. Total RNA extracted from livers of treated fish and vehicle-injected controls was analyzed by Northern and slot blot hybridization using an oligonucleotide complementary to a sequence in the 3' end of tilapia vitellogenin mRNA. The probe revealed an mRNA of 6.5 kb in liver from the control mature female fish which was decreased by 85% by androgen treatment. As expected, estradiol (E2) treatment induced the 6.5-kb mRNA in mature male tilapia. The antiestrogen, tamoxifen, strongly decreased vitellogenin mRNA levels in mature females. Radioimmunoassay of serum from control and 17 alpha MT-treated female tilapia showed a marked reduction in serum E2 levels, from 11.4 +/- 2.6 ng/ml in controls to 2.2 +/- 0.13 ng/ml in treated fish. Tamoxifen, however, resulted in increased serum E2 levels, probably by blocking E2 negative feedback. The serum E2-lowering effect of 17 alpha MT suggests an inhibitory site of action on gonadotropin production at the hypothalamic-pituitary axis, possibly through an androgen receptor or through an estrogen receptor after local aromatization of 17 alpha MT.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0016-6480
pubmed:author
pubmed:issnType
Print
pubmed:volume
104
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Androgen inhibition of vitellogenin gene expression in tilapia (Oreochromis niloticus).
pubmed:affiliation
Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia, Canada. CBLAZIE@AC.DAL.CA
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't