Linked Life Data

8514623

Source:http://linkedlifedata.com/resource/pubmed/id/8514623

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-7-16
pubmed:abstractText
In view of the evidence showing that germ cells regulate Sertoli cell (SC) function, the aim of this study was to examine if germ cell (GC)-conditioned media contained multiple biological factors that affect SC secretory functions. Total GC were isolated from adult rat testes. Pachytene spermatocytes (SPC) and early spermatids (SPT) were enriched to about 90% pure by centrifugal elutriation. GC, SPC, and SPT were cultured in serum-free medium for 20 hours with a viability greater than 95%. Conditioned media derived from these cells were fractionated by anion-exchange high-performance liquid chromatography (HPLC). An aliquot from each of these fractions was resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and proteins were visualized by silver staining. The patterns of protein staining using media from GC, SPC, and SPT were similar. Bioassays of these column fractions on SC showed that the transferrin stimulatory, the testins inhibitory, and the clusterin inhibitory activities were eluted from the anion-exchange HPLC column in overlapping fractions. To determine whether these activities were confined to one or several molecules, further fractionations were performed. Eleven liters of GC-conditioned medium were fractionated by sequential HPLC using anion-exchange, gel permeation, and reversed-phase columns. Throughout the entire fractionation scheme, the HPLC fractions were bioassayed using primary SC-enriched cultures prepared from 20-day-old rats by incubating SC with aliquots of these fractions for 24 hours to monitor their effects on SC secretory function. The concentrations of transferrin, clusterin, and testins were quantified by specific radioimmunoassays. These studies showed that the transferrin stimulatory activity can be fractionated into four peaks (I, IIa, IIb, and IIc); clusterin inhibitory activity into three peaks (A, B, and C); and testins inhibitory activity into two peaks (1 and 2). Some of these bioactivities were eluted in overlapping fractions such as I and B, IIb and 1, and IIc and 2, whereas A, C, and IIa were not associated with any other assayed activities. In summary, additional GC modulators of SC function were identified for the first time, these include clusterin and testins inhibitors. The previously identified transferrin stimulatory activity was also resolved into multiple molecular forms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0196-3635
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
87-98
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:articleTitle
Germ cell-conditioned medium contains multiple factors that modulate the secretion of testins, clusterin, and transferrin by Sertoli cells.
pubmed:affiliation
Population Council, New York, New York 10021.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't