Effect of finasteride on serum prostate-specific antigen (PSA) and on prostate of hamster Mesocricetus auratus (hMa) Efeito da finasterida no antígeno prostático específico (PSA) sérico e na próstata do hamster Mesocricetus auratus (hMa)

PURPOSE: Evaluate the effects of finasteride on the serum PSA and on the prostate of hamster-Mesocricetus auratus(hMa). METHODS: Twenty hMa male adults were split in groups control and experimental (n=10). Animals of the experimental group received 7.14ng/mL of finasteride, subcutaneously (SC) on the back three times per week, during 90 days. The finasteride dose was equivalent to 5.0mg administered to a 70kg man. At the end of the experiment the mean age for the animals in the control group was 15.2±1.13months and for the experimental group was 17.7±0.67 months. There was a statistically significant difference between mean ages of both groups (t value=5.98; p=0.001). The animals of the control group weighted 129.0±18.8g and the experimental group weighted 145.0±15.5g, t=1.88 e p=0.0514. The serum PSA was assessed through ELISA method. Prostates of those animals were collected and processed to histology and morphometry: the diameter of the acinous glands and the acinous epithelium, apoptosis, AgNORs and cellularity were assessed in both groups. RESULTS: Serum PSA decreased in the experimental group, 0.003ng/mL versus 0.763ng/mL, H= 7.982 e p= 0.0047. Decrease in the acinous area occurred in animals that received finasteride, 238.000±24.600 &#956;m² versus 398.600±55.320 &#956;m²; t= 2.653; p= 0.0122. A remarkable decrease in the area of the acinous epithelium occurred in the animals that received finasteride, 111.900±12.820 &#956;m² versus 160.400±18.430 &#956;m² t= 2.162; p= 0.0361. AgNORs were less expressed in finasteride treated animals, 2.846±0.877 versus 3.68 ±1.07 argyrophilic clusters for &#956;m², p= < 0.0001. Apoptosis was more intense in the experimental group, 53.62±1.389 than in controls, 14.76 ± 2.137, p= 0.0408. However, there was no statistical difference in the cellularity between both groups, 74.75±5.5 cells, in controls versus 65.07±13.24, in treated animals, p=0.5105. CONCLUSIONS: Use of finasteride decreased serum PSA and several histological parameters of the Hamster's prostate, such as lumen area, acinous and epithelium area, and AgNORs expression. Finasteride increased apoptosis in the prostate acinous cells although no significant difference in the cellularity could be found between the two groups of animals under study.<br>OBJETIVO: Avaliar o efeito da finasterida no PSA sérico e na próstata do hamster-Mesocricetus auratus (hMa). MÉTODOS: 20 hMa adultos machos foram divididos em grupos de 10 animais. No experimento foram administrados 7,14 ng/mL de finasterida, subcutâneo (SC), no dorso, três vezes por semana, por 90 dias, dose equivalente a 5,0 mg usada em homem de 70Kg. Ao final da pesquisa, grupo experimento apresentou idade média de 17,7 ± 0,67 meses. O grupo controle apresentou idade média de 15,2 ± 1,13 meses. O valor de t na comparação das médias das idades entre os dois grupos foi de 5,98 e p=0.0001. Os animais-controle pesaram em média 129,0 ± 18,8g e o experimento 145,0 ± 15,5g; t=1,88 e p=0,0514. Na microscopia óptica de luz e estudo morfométrico: avaliaram-se o diâmetro dos ácinos e epitélio acinar prostáticos, a apoptose, a expressão AgNORs e a celularidade. RESULTADOS: O grupo-experimento apresentou média de PSA de 0,003 ng/mL e o grupo-controle de 0,763 ng/mL, H=7,982 e p=0,0047. A área dos ácinos do grupo-experimento foi de 238,000±24,600 &#956;m² versus 398,600±55,320 &#956;m²; t= 2,653; p= 0,0122. A área do epitélio acinar no grupo-experimento foi de 111,900±12,820 &#956;m² versus 160,400±18,430 &#956;m² t= 2,162; p= 0,0361. A expressão de AgNORs foi menor no grupo-experimento 2,846±0,877 versus 3,68 ±1,07 grumos argilófilos por &#956;m², p= < 0,0001. A apoptose foi mais freqüente no grupo-experimento, 53,62±1,389 versus controle, 14,76 ± 2,137, p= 0,0408. Não houve diferença na celularidade entre os grupos de animais, 74,75±5,5 células no grupo-controle versus 65,07±13,24, no grupo-experimento, p= 0,5105. CONCLUSÕES: A finasterida diminuiu o PSA sérico, a área do lúmen, o epitélio acinar, a expressão de AgNORs e promoveu a apoptose nos ácinos da próstata dos hamsteres experimento e não houve diferença na celularidade acinar entre os animais estudados