Journal of Lipid Research, Vol 21, 862-867, Copyright © 1980 by Lipid Research, Inc.
Lipid composition and gonadotropin-mediated lipid metabolism of the M5480 murine Leydig cell tumor
DH Albert, M Ascoli, D Puett and JG Coniglio
The effects of human choriogonadotropin (HCG) stimulation on lipid
composition in the murine Leydig cell tumor M5480 grown subcutaneously were
determined. The main lipids of the Leydig cell tumor were found to be
largely triacylglycerols and phospholipids. Daily in vivo administration of
human choriogonadotropin to tumor-bearing mice for 3 days increased the
phospholipid content and altered the phospholipid composition of the
tumors. There was no demonstrable change in the levels of triacylglycerols,
cholesterol, and cholesteryl esters. HCG had no major effect on the fatty
acid patterns of the major lipid fractions with the exception of
cholesteryl esters, which had a decreased amount of arachidonic acid
following HCG-treatment. Results of in vitro incubations of tumor cells
prelabeled with [1- 14C]arachidonate showed that the label was lost more
rapidly from cholesteryl esters of HCG-treated cells than from control
cells during (the 12-hour) incubation. Moreover, less [1-14C]acetate was
incorporated into the cholesteryl ester fraction of hormone-treated cells
than in control cells. HCG stimulated the activity of cholesteryl ester
hydrolase in dispersed cells within 3 hours. These results demonstrate that
an acute effect of HCG on tumor Leydig cell metabolism is to increase the
metabolism of cholesteryl esters, probably by stimulating cholesteryl ester
hydrolase activity. The long term effect is an accumulation of
phospholipids which may be utilized for membrane synthesis.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
