Fine structure of the interstitium of the epididymis of the South American Opossum (Didelphis azarae, Marsupialia).

The interstitial space of the ductus epididymidis of the opossum (D. azarae), contains fibers and cell elements of the connective tissue, smooth muscle cells and amyelinic nerve fibers. This structure, studied through TEM, is similar to the fine structure of the interstitium of the epididymis in rodents. However, the normal occurrence of mast cells in the interstitial space of the ductus epididymidis in opossum, seems to be a peculiar morphological characteristic of this species.