Linked Life Data

10698170

Source:http://linkedlifedata.com/resource/pubmed/id/10698170

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-3-16
pubmed:abstractText
Macrophages are known to release a lipophilic factor that stimulates testosterone production by Leydig cells. This macrophage-derived factor (MDF) is thought to be physiologically relevant, because removal of macrophages from the testis results in altered testosterone secretion and reduced fertility. The purpose of the present study was to purify this factor, elucidate its chemical structure, and determine whether it is both present in the testis and acts when injected intratesticularly. Culture media from testicular and peritoneal macrophages were extracted with ether, and the organic phase was sequentially purified on C18, silica, and cyano-HPLC columns. MDF was detected using a rat Leydig cell bioassay, with testosterone secretion being the end point. Purified material and crude ether extracts were analyzed by gas chromatography/mass spectrometry and nuclear magnetic resonance spectroscopy. The time of elution of MDF from both testicular and peritoneal macrophages was identical on all three HPLC columns. A single peak was observed when MDF, obtained from the final HPLC column, was analyzed by gas chromatography. The MS fragmentation pattern of purified material from both peritoneal and testicular macrophages was identical to that of a reference preparation of 25-hydroxycholesterol. Also, the nuclear magnetic resonance spectrum of MDF was similar to that of authentic 25-hydroxycholesterol. When 25-hydroxycholesterol was subjected to the identical purification scheme as MDF, it was found to elute at the same times as MDF on all three columns and elicited activity in the Leydig cell bioassay as expected. Control medium purified identically did not contain 25-hydroxycholesterol or have biological activity. Ether extracts of testis contained 25-hydroxycholesterol, indicating that this compound is present under physiological conditions. Similarly, when 25-hydroxycholesterol was injected into the testis of adult rats, testosterone production was increased within 3 h. Taken together, these data indicate that the lipophilic factor produced by macrophages that stimulates steroidogenesis is 25-hydroxycholesterol.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
141
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
953-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Identification of the lipophilic factor produced by macrophages that stimulates steroidogenesis.
pubmed:affiliation
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock 79430, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't