Reaction catalyzed by 3alpha(or 20beta)-hydroxysteroid dehydrogenase (1.1.1.53)

		+		NADP+	=			+		NADPH
	3beta,17alpha,20alpha-trihydroxypregn-5-ene	+		NADP+	=		3beta,17alpha-dihydroxypregn-5-en-20-one	+		NADPH