Implication of acid cholesteryl ester hydrolase in the regulation of steroid biosynthesis in rat Leydig cells.
Cholesteryl ester hydrolase (CEH) activities with different pH optima, i.e. at about pH 4.0 and pH 7.0, were found in Leydig cells isolated from rat testis. Highly purified intact Leydig cells responded to human chorionic gonadotropin treatment with increased intracellular cAMP levels, increased testosterone release, and a 1.5-fold stimulation of the acid CEH activity. Treatment of non-stimulated homogenised cells with cAMP-dependent proteinkinase, cAMP and ATP lead to a 3.0-fold stimulation of the acid CEH activity. These findings suggest that interconvertible CEH with an acidic pH optimum--presumably of lysosomal location--contributes to the regulation of steroidogenesis in Leydig cells.
Löffler
B M
BM
Max-Planck-Institut für Experimentelle Medizin, Göttingen, West Germany.
Kunze
H
H
D000818:Animals; D002469:Cell Separation; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D007985:Leydig Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D002787:Sterol Esterase / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis*
D006063:Chorionic Gonadotropin; D013739:Testosterone; D000242:Cyclic AMP; D011494:Protein Kinases; D002787:Sterol Esterase