Efeito inibidor da finasterida sobre a enzima 5-alfa-redutase na prostata de gerbilos adultos (Meriones unguiculatus)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Prostatic deve1opment and differentiatíon are induced by androgens acting via mesenchymal-epithelial interactions, and during adult life the gland is maintained functionally active by reciprocal homeostatic stromal-epithelial interactions. Hormonal alterations, usually associated with the physical aspects of aging, leads to disruptions of this homeostatic interactions and may initiate and promote several prostate diseases. The benign prostatic hyperplasia and cancer are among the most fi-equently prostatic pathologies and androgens, together with others factors, play important roles in the etíology ofthese lesions in the prostate. Understanding the physiology of androgen production and its role in development and maintenance of the normal prostate and in prostate cancer, it is vital in order to comprehend the complex interactions between epithelium and stroma. Within the prostate, the androgen action is enhanced due to the conversion of testosterone in dihydrotestosterone, by 5a-reductase, an enzyme mostly present in basal and stromal cells. Thus, the objective ofthis study was to analyze the alterations in tissular morphology of the adult gerbil (Meriones unguiculatus) ventral prostate, including modifications in the tissue architecture, cell ultrastructure and extracellular matrix fibers arrangement, following finasteride therapy, a competitive Sa-reductase inhibitor. The data obtained afier oral frnasteride administration, at a dose of 100mglkglday through 10 days revealed a striking reorganization ofthe stromal compartment and epithelial modifications, probably due to the new hormonal situation. The glandular epithelial compartment shrinked and its secretory activity decreased. In the stromal compartment, there was a notable collagen and reticular fibers accumulation around the epitheliurn, which assumed very different phenotypes when compared to the control animaIs prostate. The smooth musc1e layer underwent a loosening, interspersed with abundant amorphous granular material, collagen and reticular fiber. This amorphous granular material also accumulated in the base of the epithelium. Some smooth musc1e cells exhibited a dedifferentiated aspect with a higWy irregular external contour and numerous spine-like cytoplasmic projections, whereas others were reduced, showing a condensed cytoplasm and many caveolae in the cell surface. ln these regards, the results lend support to conc1ude that the 5a-reductase inhibition affected the homeostatic epithelial-stromal interactíons, what can be critically involved with the alterations of hormonallevels

ASSUNTO(S)

matriz extracelular citoquimica prostata

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