Reaction catalyzed by 3-oxo-5alpha-steroid 4-dehydrogenase (NADP+) (1.3.1.22), 3-oxo-5alpha-steroid 4-dehydrogenase (acceptor) (1.3.99.5)
+
NADPH
+
=
+
NADP+
testosterone
+
NADPH
+
H+
=
5alpha-dihydrotestosterone
+
NADP+
