androst-4-ene-3,17-dione + AH2 => 5alpha-androstan-3,17-dione + A
androst-4-ene-3,17-dione + ah2 => 5alpha-androstan-3,17-dione + a
androst-4-ene-3,17-dione + AH2 => 5alpha-androstan-3,17-dione + A
androst-4-ene-3,17-dione + ah2 => 5alpha-androstan-3,17-dione + a