A prostata ventral do gerbilo frente as diferentes formas de castração e subsequente reposição hormonal pela testosterona

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The prostate is an exocrine gland of the male genital system, which secretes part of seminal liquidolts differentiation initiates in the beginning of the embryonic development and finishes during the puberty. Testosterone (T) plays an essential role in prostate maintenance, after transformation, by 5a-reductase enzyme, to dehidrotestostorone (DHT) an more potent isoform. As Benign Prostatic Hyperplasia (BPH) and cancer may attack prostate gland, the down regulation of T levels by surgical castration (orchiectomy) or by the administration of anti-androgens drugs, such as flutamide and cyproterone acetate (chemical castration) have been the principal therapies to control these disease. The nonsteroidal antiandrogen flutamide acts by competitive inhibition of the androgen receptors (AR) in the prostate cells. The cyproterone acetate is a steroidal drug besides competing for the AR inhibits Luteinizant Hormone (LH) production on the pituitary gland that themselves inhibit T production by testis. The aim of this work was to evaluate morphologically and histochemically the behavior of prostatic tissue regression after 30 days of T ablation by orchiectomy and by chemical castration, both followed by T administration and suspension oftreatment, respectively. Two experimental groups (Ex.G. 01 and Ex.G. 02) of 20 adult gerbil (Meriones unguiculatus) each were employed. ln the Ex.G.Ol the animais underwent bilateral orchiectomy and after 30 days they received testosterone cipionate (TC) doses (25mm/Kg) during 21 days every 48 hours. They were sacrificed at O, 7, 14 and 21 days of the TC treatment beginning. Ex.G. 02 received altemates doses of cyproterone acetate and flutamide (0,3mI/animaI/day, at 25mg/Kg) dissolved in com oil, during 30 days weekly. They were sacrificed at O,7, 14 and 21 days after treatment interruption. As control group 5 animaIs not castrated (C.G.Ol) and 5 castrated animaIs (C.G.02) received com oil, the drug dilution vehicIe. Results showed that after 30 days of both surgical and chemical castration a drastic regression in the prostate weight occurred. Hormonal dosages reveled serum T leveI reduction in both surgical and chemical castration, while serum LH leveI increased during surgical castration and decreased during chemical castration. After 30 days of castration in both groups there were10 intense decreases of epithelium height, more intensive in EX.G. 02, and notable small amount of rugous endoplasmatic reticulum (RER), which characterized a low secretory activity of those cells. Some smooth muscle cells (SMC) showed a spinous and irregular phenotype along with infolding basal membrane and decrease of secretory vesicle amount. After hormonal replacement in EX.G. 01 were noted an increase in epithelial height and a greater RER quantity. Those altered SMC recovered its normal pattem and the considerable number of RER observed in the cytoplasm suggests a modulation of these cells ITom contractile to secretory phenotype. In EX.G. 02 the treatment interruption promoted an increase in epithelial height and in the amount ofRER, besides lots oflipid vesicles at basal cytoplasm. Like in EX.G. 01 SMC retook its normal phenotype, but showed an increase of RER amount to. These data leads to conclude that prostatic tissue showed a high capacity of involution after androgenic ablation and a capacity or reorganization after hormonal replacement, but the events promoted by orchiectomy and T administration appear to be more aggressive to the tissue

ASSUNTO(S)

castration androgenos - antagonistas castração antiandrogens prostata prostate

ACESSO AO ARTIGO

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