Localization of a pore-forming protein (perforin) in granulated metrial gland cells.

Several studies have suggested that the granulated metrial gland (GMG) cells of the metrial gland (MG) may be natural killer (NK)-like cells. The cytotoxicity of NK cells involves secretion of a pore-forming protein termed perforin, which can polymerize on the target cell membrane to form transmembrane pores that are thought to be involved in target cell death. In the present study, we used an antiserum against perforin to determine whether this protein can be detected immunohistochemically in GMG cells. Mouse uteri were fixed by vascular perfusion with several fixatives on Day 14 of pregnancy, and tissue sections were labeled by an indirect immunofluorescence method. Specific perforin labeling was detected in GMG cells throughout the MG, in the decidua basalis, and in the labyrinthine placenta. The presence of perforin in GMG cells supports the suggestion that they may be NK-like cells.