these include their apparent km for progesterone ( microsomal km = 113 +/- 11 nm ; solubilized km = 144 +/- 20 nm ) and their affinity ( approximately 7 nm ) for the 5 alpha-dihydroprogesterone analog , 4-aza-4-methyl-5 alpha-pregnane-3,20-dione , which is a potent inhibitor of progesterone 5 alpha-reduction .
C0012311
dihydroprogesterone
C0033308
progesterone