Anatomical and immunohistochemical characteristics of the prostate gland in the greater cane rat (Thryonomys swinderianus).

This study examined the morphology and immunohistochemical features of the prostate gland in 15 captive-reared male greater cane rat of known reproductive and medical history. Samples of the glands were taken after gross examination and routinely prepared for both histological and ultrastructural analysis. Immunohistochemistry was also carried out on paraffin-embedded sections of the glands using rabbit polyclonal antibodies against oestrogen receptors (ERα and ERβ) and mouse monoclonal antibody for the progesterone receptor (PR). The prostate, which constitutes 0.04% of the body weight, was a paired, lobulated, brownish gland having three left and four right lobes that partly cover the pelvic urethra. Based on the amount and arrangement of the secretory epithelial folding and relative to their distances to the urethra, two histological zones, the central and peripheral, were identified. However, the epithelium of both zones was lined by predominantly simple cuboidal cells with occasional basal cells. The main ultrastructural features of these cuboidal cells were the presence of several nuclear pores on the nucleus, moderately well-developed, short microvilli and bleb-like apical projections, as well as inter-cellular lacunae seen between these cells and the basal cells. The cuboidal epithelial cells also showed positive nuclear staining for ERα and ERβ but not for PR. It is however interesting that the ERα-positive staining was more at the epithelial cells, which is uncommon. These findings highlight the peculiarities in the structure and ultrastructure as well as the unique expression of the oestrogen receptors in the prostate gland of the greater cane rat.