Mononuclear phagocytes (monocytes and macrophages) represent a substantial cellular population in the normal testicular interstitial tissue of the human and experimental rodent species. In the adult rat testis, these cells belong to one of two distinct subsets, differentiated by the expression of the resident macrophage surface antigen recognized by monoclonal antibody ED2 and a lysosomal marker recognized by monoclonal antibody ED1. The majority of mononuclear phagocytes within the rat testis are ED2+ resident-type macrophages, but there is also a significant population of ED1+ED2~ cells that presumably represents circulating monocytes or recently arrived macrophages (monocyte/macrophages), as well as dendritic cells. buy antibiotics online
There is considerable evidence that the testicular macrophages and the Leydig cells have close functional links. Total rat testicular macrophage numbers gradually decline below normal levels following a brief period of elevation when Leydig cells are ablated by treatment with the specific Leydig cell cytotoxin ethane dimethane sulfonate (EDS). Similarly, macrophage numbers decline when pituitary gonadotropins are selectively withdrawn.