Prostatic Ductal System in Rats: Regional Variation in Morphological and Functional Activities1

Abstract

The rat prostate is a complex ductal system with branches and subbranches extending from one end to another. Owing to the relative distance of various regions of the duct from the urethra, the entire length of the ductal system can be arbitrarily divided into three segments, i.e., the proximal, intermediate, and distal segments. The present study was carried out to assess the regional variation in cellular activities in this ductal system. Ventral prostates from adult Sprague-Dawley rats were dissected so that an individual ductal system was mechanically isolated and longitudinally sectioned to reveal various segments. Epithelial cells lining distal segments were tall-columnar type and were actively engaging in mitotic activity. Cells in intermediate segments were also tall-columnar type. However, they were mitotically quiescent, but able to produce secretory proteins. Evidence of programmed cell death was not observed in either of these two segments. Cells in proximal segments, on the other hand, were low-columnar or cuboidal in shape and were stained heavily for cathepsin D, a marker associated with late manifestation of cell death. Following castration in adult rats, there was a reversal in the site of programmed death in cells lining the ductal system. By Day 4 post-castration, distal segments contained many epithelial cells with intense cytoplasmic staining for cathepsin D while proximal segments showed a reduction in number of positively stained cells. By Day 7 post-castration, cells in proximal segments, though atrophied, were devoid of staining for cathepsin D.(ABSTRACT TRUNCATED AT 250 WORDS)

Lobe Identity in the Mongolian Gerbil Prostatic Complex: A New Rodent Model for Prostate Study

“…DeKlerk and Coffey (1978) and Sugimura et al, (1986a,b) reported that the epithelial and stromal cells of different regions of the prostatic lobes respond differently to androgenic privation and stimulation, suggesting a functional heterogeneity inside the lobe. Therefore, in addition to the main ducts in prostate lobes of some rodents already studied, three morphologically and functionally distinct regions called distal, intermediate, and proximal, according to the position occupied in relation to the urethra, have been recognized (Lee et al, 1990;Banerjee et al, 1994;Nemeth and Lee, 1996). Nemeth and Lee (1996) have described how the regional differences along the duct system of the VL in rats, even in the acinar epithelium as in the stromal compartment, reflect differences in secretion levels, proliferation, and cellular death.…”

“…In the hopping mouse, the VL is the only component of the prostatic complex (Tsonis et al, 1981). Thus several studies have reported that there are considerable differences in the ductal array, histology, and hormonal sensitivity among the prostatic complex lobes in laboratory rodents (Jesik et al, 1982;Sugimura et al, 1986a;Lee et al, 1990;Hayashi et al, 1991;Banerjee et al, 1994;Kinbara and Cunha, 1996). It is known that these differences are, at least in part, a consequence of morphogenesis (Sugimura et al, 1986a), and recently the Hox genes have been indicated as distinct expression of genetic patterns involved in lobe identity (Huang et al, 2004).…”

Development of a Transgenic Stem Cell Model of Prostate Cancer

“…Finally, the proximal ducts of the mouse prostate express Cathepsin D, a marker of apoptosis (Lee et al 1990). No equivalent zone has been demonstrated in the human prostate.…”

“…Second, while basal cells comprise the majority of proliferating cells in the human prostate, most proliferative activity in the mouse prostate is localized to columnar cells lining the distal regions of the prostatic ducts (Lee et al 1990;Sugimura et al 1996). Third, secretory activity in the murine prostate is maximum in intermediate regions of the duct, compared to humans in which no such regional heterogeneity has been reported (Lee et al 1990). …”

Growth, regeneration, and tumorigenesis of the prostate activates the PSCA promoter

“…A majority of proliferating cells are located at the tips of the ducts, whereas the proximal ducts attached to the urethra contain a high percentage of apoptotic cells (11,12). Secretory activity has been proposed to be concentrated in the intermediate regions of the duct.…”