Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-8-30
pubmed:abstractText
It has been shown recently that insulin enhances differentiation of rat, pig, and human granulosa cells. The present studies were done to determine if insulin also plays a role in the regulation of theca cell steroidogenesis. Theca cells were obtained from prepubertal gilts and cultured under serum-free conditions for 48 h. Theca cell androstenedione production under basal and luteinizing hormone (LH)-stimulated conditions was significantly increased by adding insulin (1 microgram/ml) to the culture medium. Treatment of basal and LH-stimulated cultures with increasing concentrations of insulin (0.001-10 micrograms/ml) caused dose- and time-dependent increments in androstenedione production, but the effect was independent of the dose of LH employed. The ability of insulin to enhance thecal cell androstenedione production was mimicked by somatomedin C, but not by relaxin. Studies to determine the mechanism(s) of action of insulin showed that insulin action is exerted, at least in part, at a site(s) proximal to cyclic adenosine 3'5'-monophosphate (cAMP) generation, since insulin enhanced both basal and LH-stimulated accumulation of extracellular cAMP in addition to increasing androstenedione production. This effect was further enhanced by 3-isobutyl-1-methyl xanthine, an inhibitor of phosphodiesterase activity. Insulin treatment also caused dose-dependent increments in forskolin- and prostaglandin E2-stimulated accumulation of extracellular cAMP and androstenedione. Insulin also increased both the basal and LH-stimulated production of progesterone and its precursor pregnenolone, in addition to the increases in androstenedione.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/1-Methyl-3-isobutylxanthine, http://linkedlifedata.com/resource/pubmed/chemical/25-hydroxycholesterol, http://linkedlifedata.com/resource/pubmed/chemical/Androstenedione, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/Dinoprostone, http://linkedlifedata.com/resource/pubmed/chemical/Forskolin, http://linkedlifedata.com/resource/pubmed/chemical/Hydroxycholesterols, http://linkedlifedata.com/resource/pubmed/chemical/Insulin, http://linkedlifedata.com/resource/pubmed/chemical/Insulin-Like Growth Factor I, http://linkedlifedata.com/resource/pubmed/chemical/Luteinizing Hormone, http://linkedlifedata.com/resource/pubmed/chemical/Pregnenolone, http://linkedlifedata.com/resource/pubmed/chemical/Progesterone, http://linkedlifedata.com/resource/pubmed/chemical/Relaxin
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
735-43
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Insulin enhances luteinizing hormone-stimulated steroidogenesis by porcine theca cells.
pubmed:affiliation
Department of Physiology, University of Western Ontario, London, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't