Linked Life Data

2533115

Source:http://linkedlifedata.com/resource/pubmed/id/2533115

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1990-3-7
pubmed:abstractText
By using immature porcine Leydig cells cultured in defined medium as a model, transforming growth factor-beta (TGF beta) was shown to exert a dramatic inhibitory effect on their basal and human chorionic gonadotropin (hCG) (or 8-bromo-cyclic AMP) stimulated dehydroepiandrosterone secretion, in the presence or absence of saturating concentrations of exogenous (low density lipoprotein) cholesterol substrate. In contrast, TGF beta exerted both a stimulating and inhibitory effect on testosterone secretion: while hCG-stimulated testosterone secretion was enhanced by low doses of TGF beta (0.06-0.4 ng/ml, 48 h), it was decreased with higher concentrations of TGF beta (2.5-10 ng/ml, 48 h). The data obtained show that the inhibitory action of TGF beta on testicular steroidogenesis was related to a decrease in pregnenolone formation by affecting a step(s) distal to cyclic AMP formation but before cholesterol association with cytochrome P-450 side-chain cleavage. As for the stimulatory effect of TGF beta on testosterone formation, this was mainly related to an increase (about 2-fold) in 3 beta-hydroxysteroid dehydrogenase/isomerase activity (ED50 0.05 ng/ml, 2 X 10(-13) M). The results indicate that the (short-term) steroidogenic stimulatory action of luteinizing hormone (LH)/hCG is antagonized by high concentrations of TGF beta by decreasing pregnenolone formation while it is enhanced by the stimulating action of low concentrations of TGF beta exerted on 3 beta-hydroxy steroid dehydrogenase/isomerase activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
155-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
On the mechanisms involved in the inhibitory and stimulating actions of transforming growth factor-beta on porcine testicular steroidogenesis: an in vitro study.
pubmed:affiliation
Laboratoire de Biochimie, Hôpital Sainte Eugénie, Centre Hospitalier Lyon-Sud, France.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't