Linked Life Data

9916024

Source:http://linkedlifedata.com/resource/pubmed/id/9916024

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-4-13
pubmed:abstractText
Exposure to disease or injury often results in impaired reproductive activity accompanied by decreased testosterone levels. After immune activation, the cytokine interleukin 1-beta (IL-1beta) circulates in high concentrations, and its exogenous administration evokes many of the sequelae of immune activation. Previously, we have shown that the administration of this cytokine into the cerebral ventricles blunts hCG-stimulated testosterone secretion. This effect, though time-dependent, occurs before significant elevation of interleukin 6 in the peripheral bloodstream, does not depend on adrenal activation, and/or changes in LH concentrations, leading us to hypothesize a direct connection between the brain and testis. To explore this mechanism further, we isolated testicular tissue from rats treated intracerebroventricularly (icv) with vehicle or IL-1beta 30 or 90 min before they were killed. We found that in vivo cytokine treatment blunted ex vivo testosterone secretion in response to hCG, showing that the mechanism is independent of circulating cytokines. Though hCG binding was moderately reduced by icv IL-1beta in these preparations, the extent of this inhibition did not explain our observations. As the first acutely and hormonally regulated step in the biosynthesis of testosterone is the transfer of cholesterol into the inner mitochondrial membrane, which is mediated by steroidogenic acute regulatory (StAR) protein, we hypothesized that the rapid effects of icv IL-1beta on testicular responsiveness to hCG might be due to reduced levels of StAR. We report here that StAR protein was indeed reduced in Leydig cells isolated from rats treated in vivo with IL-1beta. Furthermore, treatment with a water-permeable form of cholesterol that bypasses the requirement for StAR partially restored hCG-stimulated testosterone secretion from testes isolated from rats treated icv with IL-1beta. Taken together, our data indicate that StAR plays a role in the suppression of testicular function evoked by central administration of IL-1beta.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
527-33
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
The inhibitory effect of intracerebroventricularly injected interleukin 1beta on testosterone secretion in the rat: role of steroidogenic acute regulatory protein.
pubmed:affiliation
The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.