Abstract
Normal, term, human placentas are a rich source of a 15-hydroxyprostaglandin dehydrogenase. The enzyme is extremely labile, and partial purification could be achieved only after stabilization with glycerol. The instability of the enzyme and its K m for NAD are indications that it is different from the 15-hydroxyprostaglandin dehydrogenase isolated from swine lung. Human placental tissue should provide a very useful source from which large amounts of highly purified 15-hydroxyprostaglandin dehydrogenase may be obtained.