17beta-hydroxyandrosta-1,4-dien-3-one + NADPH + H(+) <=> 17beta-hydroxy-5beta-androst-1-en-3-one + NADP(+)
17beta-hydroxyandrosta-1,4-dien-3-one + nadph + h(+) <=> 17beta-hydroxy-5beta-androst-1-en-3-one + nadp(+)