The content and immunohistochemical localization of placental protein 10 (PP10) in the fallopian tube.

Radioimmunoassay, gel filtration and immunoperoxidase staining were used to study the content and localization of placental protein 10 (PP10) in 15 fallopian tubes removed on medical grounds from patients aged between 35 and 53 years. PP10 was consistently present in all parts of the tube at all ages and in all phases of the menstrual cycle. The PP10 concentration in tissue ranged from 0.08 to 2.95 micrograms/g of tubal cytosol protein. Immunoperoxidase staining localized PP10 in monocytic and lymphoid cells that were unevenly scattered in the subepithelial layer of the mucosa. In gel filtration, PP10 from the fallopian tube and purified placental PP10 eluted in the same volume, and graded amounts of PP10-immunoreactive material from the tube and purified PP10 gave parallel dose-response curves in radioimmunoassay. We conclude that PP10 is another 'placental protein' that has been identified in the fallopian tube.