Reposição hormonal na prostata ventral de ratos castrados : recuperação glandular, reorganização estremal e atividade de metaloproteinases de matriz

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The ventral prostate (VP) and the seminal vesic1e (SV) are both androgen dependents, in which undergoe atrophy and regrowth processes afier androgen deprivation and reposition. In both events, it was observed alterations in the epithelium as well as in the stromal compartiments. The aspects related to the prostate epithelium induced by testosterone replacement in castrated rats are very well discribed, however the estromal modifications and matrix metalloproteinases (MMPs) activity are not, even not a comparative study of proliferative responsiveness between VP and SV to testosterone replacement. In this sense, the aim of this work was: a) to compare the responsiveness to androgen reposition of the VP and SV involuted; b) to describe the process of stromal reorganization of castrated ventral prostate submited to testosterone replacemnt; c) to analyse the gelatinolitic activity of MMP-2 and MMP-9 in the ventral prostate during castration and androngen reposition; For this, male adult Wistar rats (3 months-old) were divided into 3 experimental groups: control, castrated (testis excision), and castrated plus testosterone replacement. The animals from castrated group were sacrificed at 3,5, 7, 21, 24, 26, 28 and 31 days after castration, while those from testosterone replacement, afier 21 days of castration, started to receive daily doses of testosterone propionate (4mg/kg/day) and were sacrificed at 3, 5, 7 and 10 days afier testosterone replacement. Finally, the animals from control group were sacrificed at 3, 7, 21 and 31 days afier beginning the experimento The animals were killed and weighted. The VPs and SVs were weighted and processed for histochemistry, immunohistochemistry, morphometric-stereological, ultra-structural and zymography analyses. The results were analysed statistically. Castration induced the characteristic process of involution. This process was progressively reverted by the testosterone replacement. However, at the end of the treatment, the more responsiveness of SV was demonstrated. The SV from TESTO group overcome the control value, while the VP did not reach the control value. This difference between two glands was also observed in the proliferation index (PI) obtained by the immunoreaction for PCNA. The epithelial cells from involuted SV presented a PI value about 3 times higher than that from VP. In despite castration promote an increase in the stromal area, our results from stromal absolute volume showed a reduction in the estromal compartiment, with a probably degradation of extracellular matrix. Moreover, the condensed colagen, reticular and elastic fibers have been distended and dispersed during testosterone replacement. In fact occured a progressive increase in the stromal absolute volume, suggesting synthesis of this components. These results confnm the ultrastructural observations of fibroblasts and smooth musc1e cell with enlarged rough endoplamatic reticulum cistems and Golgi complex evident. In the degradation of extracellular matrix components from stroma during castration, certainly the participation of MMPs is present. MMP-2 and -9 exhibited increased gelatinolytic activity of latent and mainly of active forms. The MMP-9 presented higher activity during the late phase of glandular involution, while the MMP-2 presented increased activity in both castration and testosterone replacement processes. These results shown that androgen modulate the prostate physiology and influence the composition and organization of stromal extracellular matrix through smooth muscle cells and mainly fibroblasts

ASSUNTO(S)

metaloproteinase prostata matriz extracelular

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