to study the biosynthesis of 20 alpha-dihydropregnenolone-sulfate ( 20p5-s ) and 20 alpha-dihydroprogesterone ( 20p4 ) in the feto-placental unit , human fetal liver and placenta were incubated with various radioactive precursors which included 14c-pregnenolone ( p5 ) , 14c-progesterone ( p4 ) , 14c-20 alpha-dihydropregnenolone ( 20p5 ) and 14c-20p5-s .
C0012311
20 alpha-dihydroprogesterone
C0033308
progesterone