The prostate comprises a glandular epithelium embedded within a fibromuscular stroma. The stroma is a complex arrangement of cells and extracellular matrix (ECM) components in addition to growth factors, regulatory molecules, remodelling enzymes, blood vessels, nerves and immune cells. The principal sources of ECM components are fibroblasts and smooth muscle cells (SMC), which synthesize the structural and regulatory components of the ECM. Telocytes (TCs) were recently described as a novel stromal cell type that exhibited characteristic features. The aim of this study was to confirm the presence of TCs in prostate stromal tissue of gerbils, as the stromal compartment of this gland is a dynamic microenvironment. We used transmission electron microscopy (TEM), light microscopy and immunohistochemistry methods to provide morphological evidence for the presence of TCs. Cells that resembled TCs were observed in gerbil prostatic stroma. These cells had small cellular bodies with very thin and extremely long cellular processes. They were found primarily in the subepithelial area and also at the periphery of SMC layers. TCs also exhibited moniliform processes, caveolae and nuclei surrounded by small amounts of cytoplasm. Close contacts between TC podomers were evident, particularly in the adjacent epithelial compartment. This morphological evidence supported the presence of TCs in the gerbil prostatic stroma, which we report for the first time.

The hormonal oscillations that occur during the female reproductive cycle influence the morphophysiology of several organs of the reproductive system. The female prostate is a functional organ sensitive to the action of steroidal hormones, but it is not known whether the hormonal oscillations that occur during the reproductive cycle can alter the biology of this gland. Thus, the present work aims to evaluate the morphofunctional aspects of the female prostate during the gerbil estrous cycle. For this purpose, morphological, morphometric-stereological, serological, and immunocytochemical analyses were carried out. The results of the present study show that the hormonal oscillations that occurred during the estrous cycle altered both the structure and functionality of the gerbil female prostate. These alterations include increased prostatic growth and augmented secretory activity during the proestrus and estrus phases and a gradual decrease of the secretory activity and glandular development in the diestrus I and II phases. These cyclical oscillations appear to be determined by the hormonal peaks of estrogen in diestrus II and by the high levels of progesterone during estrus, since the androgen levels remained constant throughout the estrous cycle.

Testosterone (T) and oestrogen are the main active steroid hormones in the male and female reproductive system respectively. In female rodents progesterone (P4), together with testosterone and oestrogen, has an essential role in the regulation of the oestrous cycle, which influences the prostate physiology through their oscillations. In this work we investigated how the male and female prostate gland of Mongolian gerbils responds to surgical castration at the start of puberty and what are the effects of T, oestradiol (E2) and P4 replacement, using both quantitative and qualitative methods. We also examined the location of the main steroid receptors present in the prostate. In the castrated animals of both sexes an intense glandular regression, along with disorganization of the stromal compartment, and abundant hyperplasia was observed. The replacement of P4 secured a mild recovery of the glandular morphology, inducing the growth of secretory cells and restoring the androgen receptor (AR) cells. The administration of P4 and E2 eliminated epithelial hyperplasia and intensified gland hypertrophy, favouring the emergence of prostatic intraepithelial neoplasia (PIN). In animals treated with T and P4, even though there are some inflammatory foci and other lesions, the prostate gland revealed morphology closer to that of control animals. In summary, through the administration of P4, we could demonstrate that this hormone has anabolic characteristics, promoting hyperplasia and hypertrophy, mainly in the epithelial compartment. When combined with E2 and T, there is an accentuation of glandular hypertrophy that interrupts the development of hyperplasia and ensures the presence of a less dysplastic glandular morphology.

Maternal malnutrition due to a low-protein diet is associated with functional disorders in adulthood, which may be related to embryonic development failures. The effects of gestational protein restriction on prostate morphogenesis in male offspring were investigated. Pregnant rat dams were divided into normoprotein (NP; fed a normal diet containing 17% protein) and hypoprotein (LP; fed a diet containing 6% protein) groups. On the day of birth (PND1), anogenital distance and bodyweight were measured in male pups. Seven males per experimental group (one male per litter) were killed, and the pelvic urethra was evaluated. LP offspring showed a significant reduction in bodyweight and anogenital distance on PND1. On three-dimensional reconstruction of the prostate, the number of prostatic buds was lower in LP than in NP males. Mesenchymal cells surrounding the buds were androgen-receptor positive, and the quantity and intensity of nucleus immunoreactivity was decreased in LP. The proliferation index was lower in LP than in NP prostatic buds. Immunoreactivity for α-actin in mesenchymal cells and that for epidermal growth factor receptor in epithelial cells was higher in NP than in LP. Our findings demonstrate that maternal protein restriction delays prostatic morphogenesis, probably because of considerable disruption in the epithelium-mesenchyme interaction.

The gerbil female prostate undergoes morphological and physiological changes resulting from hormonal fluctuations that occur during the reproductive cycle. These repetitive cycles of glandular growth and regression are followed by an extensive reconstruction and remodeling of prostate stroma throughout the reproductive life of the female gerbil. The objective of this study was to evaluate the effect that the hormonal fluctuations of the reproductive cycle have on the stromal remodeling and the expression and activity of matrix metalloproteinases MMP-2 and -9 in the adult female gerbil prostate. For this, serological, ultrastructural, immunohistochemical and biochemical methods were employed. The results showed that the major stromal alteration coincide with the peak of estradiol, which occurs in estrus, and with the peak of progesterone, occurring during diestrus II. MMP-2 and -9 presented a similar pattern of expression and activity during estrous cycle. The estrus was the phase of greater expression and activity of MMP-2 and -9. On the other hand, in DI and DII, the tissue expression and activity of MMP-2 and -9 was very weak. These results are important since they suggest the involvement of estradiol and progesterone in regulating the expression and activity of MMP-2 and -9 in adult gerbil female prostate.

Glucocorticoids (GCs) are hormones that are widely used in medicine; but although side effects are generally recognised, little is known about the precise mechanisms that is implicated in many of these side effects. Furthermore, GCs are highly correlated with stress and behaviour disorders. This study evaluated the effects of the glucocorticoid corticosterone on the ventral prostate of the Mongolian gerbil. Male gerbils (Meriones unguiculatus) (n = 5) received intraperitoneal injections of saline or corticosterone in doses of 0.5 mg/kg/day and 1.5 mg/kg/day for 5 days; while some of the animals were killed immediately after the treatment, the others were killed 5 days after the treatment period. The data show that corticosterone influences the structure and functionality of this organ. This hormone has anti-proliferative and anti-apoptotic properties in the prostate. In addition, the frequencies of the androgen (AR), oestrogen (ERα, ERβ) and glucocorticoid (GR) receptors changed. The frequencies of AR, GR and ERβ decreased in the Ct1/5 group; in the groups with rest period, the frequencies of GR increased and ERβ decreased in the epithelium. Changes in the proliferative index, apoptotic index and receptor activity may have contributed to the emergence of prostatic morphological alterations, such as the presence of cellular debris and inflammatory cells. Different doses of corticosterone had variable effects on the prostate, with a higher dose showing subtler effects and a lower dose showing more striking effects. The corticosterone effects on nuclear receptors were reverted or attenuated after a rest period, which was not observed for proliferation and apoptosis. In summary, we have demonstrated that corticosterone might influence the prostatic morphophysiology and that these changes may be linked in some way to the altered receptor distribution.

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