It has been reported that testicular Sertoli cells can be induced to synthe
size the steroidogenic acute regulatory (StAR) protein. StAR mediates the r
ate-limiting step of steroidogenesis, which is the transfer of cholesterol
to the inner mitochondrial membrane. Since Sertoli cells are thought to be
unable to utilize cholesterol for the synthesis of steroids the role of StA
R in these cells was questioned. In the present studies we have corroborate
d the induction of StAR protein in immature cultured Sertoli cells in respo
nse to either trophic hormone or cAMP analog stimulation. Further, we have
shown that long term stimulation of Sertoli cells with cAMP analog results
in the induction of P450sec enzyme and increased pregnenolone production. I
n this manner, the Sertoli cell may resemble its ovarian homolog, the granu
losa cell, more closely than previously thought with regards to its steroid
ogenic capacity. Thus, StAR may play the same role in Sertoli cells as it d
oes in other steroidogenic tissues. (C) 1999 Elsevier Science Ireland Ltd.
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