Immunohistochemical localization of PGF2 alpha receptor in the rat oviduct

As a step towards understanding the role of prostaglandin F2 alpha (PGF2 alpha) in female reproductive tract physiology, a rabbit polyclonal antiserum reactive with purified PGF2 alpha receptor (PGF2 alpha-R) was produced. Here we describe use of this anti-PGF2 alpha-R antiserum in immunohistochemical staining of rat oviduct to ascertain which cell types, in vivo, possess immunoreactive PGF2 alpha-R. Western blot analysis was initially performed and confirmed that the anti-PGF2 alpha-R antiserum recognizes only one oviductal antigen. The immunopositive antigen is similar in molecular mass (by PAGE) to the previously described, purified PGF2 alpha-R molecule. Immunohistochemical staining demonstrates that adult rat oviduct contains a single subpopulation of cells with PGF2 alpha-R, and that subpopulation is a ciliated epithelial cell type found predominantly in the isthmus and distal ampullae near the isthmus-ampullae junction (I-AJ). None of these PGF2 alpha-R immunopositive cells are found in the epithelium of infundibulum oviduct. PGF2 alpha-R containing cells are not randomly distributed in the epithelium on cross-section of the isthmus and ampullae oviduct, rather, they are almost always in the crypts between infoldings of the mucosa. The relative number of this I-AJ PGF2 alpha-R containing epithelial cell subpopulation appears to vary with the phase of the rat's estrus cycle. Diestrus I-AJ epithelium contains one-half to one-third as many PGF2 alpha-R containing cells as it does in proestrus, estrus or metestrus.(ABSTRACT TRUNCATED AT 250 WORDS)