Intraepithelial leucocytes in the bovine uterine tube

The epithelium of the uterine tube consists of ciliated cells and secretory cells. Basal cells are a third cell type observed in tubal epithelium and they are located principally in the basal part of the epithelium. The objec tives of this study were to characterize these basal cells in normal and su perovulated heifers and to determine whether they participate in the replac ement of the ciliated and secretory cell populations. All heifers received cloprostenol (PG) to induce oestrus (day 0). Superovulated heifers received 24 mg pFSH at doses of 4.5, 3.5, 2.5 and 1.5 mg given twice daily. Control and superovulated heifers were slaughtered on days 1, 3, 5 and 7 of the oe strous cycle. Another group of normal cycling heifers was slaughtered on da ys 2-3 and 11-13 of the oestrous cycle and used for immunocytochemistry. Sa mples from ampulla, pre-isthmus and isthmus of the uterine tube were collec ted and processed for light and transmission electron microscopy. Quantitat ive examination by light microscopy showed that there was a significant dif ference in the number of basal cells between the regions of the heifers' ut erine tube. On the basis of ultrastructure two populations of basal cells w ere observed. One (type I) had a nucleus with much condensed heterochromati n and very sparse cytoplasmic organelles. The second cell (type II) had a n ucleus with heterochromatin typically clumped around the nuclear envelope. Its cytoplasm contained many organelles including a number of lysosomes, Th e ultrastructural features of these cells were similar in all regions and a t all days of the oestrous cycle examined. Immunocytochemistry revealed tha t type basal cells were lymphocytes and type II basal cells were macrophage s, Copyright (C) 2000 S. Karger AG, Basel.