Reaction catalyzed by 3-oxo-5alpha-steroid 4-dehydrogenase (NADP+) (1.3.1.22)
+
NADPH
+
=
+
+
testosterone
+
NADPH
+
H+
=
androstan-3alpha,17beta-diol
+
androstan-3beta,17beta-diol
+
5alpha-dihydrotestosterone
