Demonstration of pregnancy-associated plasma protein-A (PAPP-A)-like material in the fallopian tube.

The distribution and concentration of pregnancy-associated plasma protein-A (PAPP-A) in the human fallopian tube were examined by the immunoperoxidase staining technique and radioimmunoassay as part of a detailed study of PAPP-A in the nonpregnant state. PAPP-A-like material was identified in the epithelial cells of the mucosa in all fallopian tube specimens examined (n = 21). The intensity of the staining for PAPP-A was unrelated to the phase of the menstrual cycle. PAPP-A-like material was detected in saline extracts from all tubal tissues (n = 14) but not in any of the sera obtained from the same patients. The tissue concentration (mean +/- standard error of the mean) of immunoreactive PAPP-A varied from 15.2 +/- 1.1 to 30.1 +/- 4.2 micrograms/g protein in different parts of the tubes. No difference in the PAPP-A concentration was found between isthmic, ampullar, and fimbrial part of the tube, but proliferative phase tube seems to contain more PAPP-A than secretory phase tube. The PAPP-A measured in the fallopian tube appears to be similar in molecular size and antigenicity to that of pregnancy.