Leydig Cells

In the present study, we continued investigations on the factors that render R2C cells constitutively steroidogenic. The importance of the PKA pathway was suggested when R2C cells were treated with H8Q, an inhibitor of PKA, and decreases in both Star mRNA levels and steroid production were observed. Given the complex phenotype exhibited by R2C cells […]

Constitutive StAR and Steroid Production in R2C Cells Requires PLC and PKC Activity In an effort to determine whether constitutive steroidogenesis in R2C cells is the result of increased activity of the PKC pathway, the possibility that PLC, the enzyme that produces the DAG activator of PKC, was constitutively activated in R2C cells was examined. […]

The rate-limiting enzymatic reaction in steroid biosynthesis (i.e., the conversion of free cholesterol to pregnenolone) is catalyzed by the cytochrome P450 side chain cleavage enzyme (CYP11A1; herein called P450scc). However, the physiologically relevant rate-limiting step is the transfer of free cholesterol from the outer mitochondrial membrane to the inner membrane where the P450scc resides. This […]