Presence and distribution of leucocyte subsets in the murine epididymis after vasectomy.

Male mice were vasectomized by 'open-ended' or 'closed' techniques. After 4 weeks the cell-mediated immune reactions were compared with those of sham-operated animals by immunohistochemical localization of leucocytes, using specific monoclonal antibodies. Macrophages and MHC class II antigen-positive cells were the major cell types to appear in all regions of the epididymis after both types of operation. There was recruitment of T-helper/inducer leucocytes but not of T-suppressor-cytotoxic cells. An increased presentation of macrophage-migration inhibiting factor antigen appeared in interstitial and peritubular locations. After 'closed' and 'open-ended' vasectomy granulomata developed in the epididymis. The sperm-containing lumen of these granulomata was invaded by macrophages, MHC class II-positive cells and T-helper/inducer lymphocytes. This mouse model thus reveals a significant epididymal inflammatory response of the epididymis to vasectomy.