Distribution and cytological properties of macrophages in human Fallopian tubes

The macrophages in human Fallopian tubes of women in the reproductive and p ostmenopausal periods were examined with a focus on their morphological pro perties by immunohistochemical staining and transmission electron microscop y. The fine structure of the smooth muscle cells in the Fallopian tubes was also investigated during the reproductive period, For immunohistochemical staining, we used two monoclonal antibodies that were specific for human ma crophages, namely PM-1K and PM-2K. PM-1K recognizes human monocytes/macroph ages corresponding to CD68, and PM-2K recognizes tissue macrophages. signif icantly during the menstrual and early to mid-secretory phases. in contrast , relative numbers of PM-2K-positive cells were small throughout the menstr ual cycle. In the postmenopausal period, few PM-IK-positive cells were dete cted, but PM-2K-positive cells remained. The macrophages during the secreto ry phase in the endosalpingeal stroma had well-developed intracytoplasmic o rganelles, but relatively few cytoplasmic vacuoles and granules. In the sam e phase, many cells of the monocyte/macrophage lineage appeared in the vasc ular lumen of the endosalpingeal stroma, The macrophages during the menstru al phase had well-developed intracellular organelles, with cytoplasmic vacu oles and granules of various sizes and configurations. During the late secr etory phase, just prior to menstruation, the smooth muscle cells contained few cytoplasmic filaments but electron-lucent or electron-dense lysosome-li ke bodies were seen. These findings suggested the presence of macrophages i n human Fallopian tubes. It is possible that such macrophages might be invo lved in the physiological functions of the tubes during the reproductive pe riod and moreover that they might participate in the reconstruction of the muscle layer of the tubes.