β microseminoprotein is not a prostate-specific protein. Its identification in mucous glands and secretions

• β microseminoprotein (β inhibin, PSP94), an unglycosylated protein of 94 amino acids with unknown function, is one of the predominating proteins in the secretion of the human prostate gland. In this work the authors have demonstrated that the expression of β microseminoprotein is not restricted to the prostate and that the protein has a previously unrecognized widespread occurrence in the human body. According to radioimmunoassay, β microseminoprotein immunoreactivity is present in many nonprostatic body fluids. The highest concentrations were found in secretions from the respiratory tract; in tracheobronchial fluid sometimes even at concentrations comparable to that in seminal plasma (about 1 g/l). Intermediate concentrations were found in gastric juice and some samples of secretion from the uterine cervix, whereas tears, saliva, pancreatic juice, bile, and mucus from the colon had low concentrations. According to gel chromatography, the molecular size of the β microseminoprotein immunoreactivity present in tracheal fluid, gastric juice, and secretion from the uterine cervix did not differ from that of β microseminoprotein in seminal plasma. The β microseminoprotein immunoreactive component present in gastric juice had the same amino-terminal amino acid sequence as prostatic β microseminoprotein (14 residues identified in material purified from gastric juice), providing further evidence for chemical identity of a nonprostatic β microseminoprotein with the prostatic protein. Immunohistochemical staining with affinity-purified antibodies demonstrated the presence of β microseminoprotein in many tissues, including the goblet cells in the tracheobronchial epithelium, tracheobronchial submucosal glands, certain mucosal cells in the antrum of the stomach, some glands of Brunner in the duodenum, and in parts of the mucosa of the colon. At least in the respiratory tract, the staining was localized in mucus-containing cells. β microseminoprotein immunoreactivity also was localized to the cilia of the ciliated epithelium in the respiratory tract, the fallopian tubes, and the Gartner ducts of the uterine cervix. The pattern of tissue distribution of β microseminoprotein found in this work indicates a connection of β microseminoprotein with mucous secretions.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Läkemedelskemi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medicinal Chemistry (hsv//eng)

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)