Linked Life Data

15858796

Source:http://linkedlifedata.com/resource/pubmed/id/15858796

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-6-2
pubmed:abstractText
Recent investigations have shown that estrogens have profound inhibitory effects on steroidogenic enzyme gene expressions before and after testicular differentiation in the rainbow trout, Oncorhynchus mykiss. This present study bring new data on juvenile rainbow trout treated with estrogens and androgens. Following a 8 days oral treatment of juvenile male with 17alpha-ethynyl-estradiol (EE2, 20 mg/kg diet) or 11beta-hydroxyandrostenedione (11betaOHDelta4, 10 mg/kg diet), we observed a fast and marked decrease of steady-state mRNA levels for 3betaHSD, P450scc, P450c17, and P450c11 enzymes in the testis. After completion of these treatments, mRNA levels of these enzymes remained low in EE2 treated males whereas in 11betaOHDelta4 treated males they recovered their initial levels in 8 days. This demonstrate that both androgen and estrogen treatments have profound effects on testicular steroidogenesis by decreasing steroid enzymes steady-state mRNA. After in vitro incubation of testicular explants with 17beta-estradiol (E2, 600 ng/ml of medium), we also observed a decrease of mRNA levels for 3betaHSD and P450c11. This suggest that estrogens effects could be triggered, at least to some extend, directly on the testis. We also investigated the hypothesis of a negative feedback of steroids on follicle stimulating hormone (FSH) secretion, but FSH plasmatic levels in treated fish did not showed any significant decrease. This demonstrate that FSH is not implied in this steroids inhibition of steroidogenic enzymes gene expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1040-452X
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
471-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Androgen and estrogen treatments alter steady state messengers RNA (mRNA) levels of testicular steroidogenic enzymes in the rainbow trout, Oncorhynchus mykiss.
pubmed:affiliation
Institut National de la Recherche Agronomique, Station Commune de Recherches en Ichtyophysiologie, Biodiversité et Environnement (INRA-SCRIBE), Rennes, Cedex, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't