The rat 20a - hydroxysteroid dehydrogenase ( 20ahsd ) belongs to a family member of aldo - ketoreductases used nadph as a cofactor and principally converts progesterone to 20a - hydroxyprogesterone as a lower or non - active hormone . thus 20ohsd acts as a molecular switch and makes the potent progesterone hormone into an inactive potent metabolite 大鼠20 -羟类固醇脱氢酶( 20 - hydroxysteroiddehydrogenase ， 20 hsd )属于醛酮氧化还原酶系成员，在大鼠卵巢中以nadph为辅酶将孕酮转变为低或无活性的20 -羟孕酮。
