Effects of long-term castration on the smooth muscle cell phenotype of the rat ventral prostate

• Processo: 07/07717-7
• Modalidade de apoio: Auxílio à Pesquisa - Publicações científicas - Artigo
• Data de Início da vigência: 01 de fevereiro de 2008
• Data de Término da vigência: 31 de julho de 2008
• Área do conhecimento: Ciências Biológicas - Morfologia - Citologia e Biologia Celular
• Pesquisador responsável: Hernandes Faustino de Carvalho
• Beneficiário: Hernandes Faustino de Carvalho
• Instituição Sede: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brasil
• Assunto(s): Diferenciação celular Castração Próstata Células musculares Publicações de divulgação científica Artigo científico
• Palavra(s)-Chave do Pesquisador: castração | célula muscular lisa | diferenciação celular | Próstata | Biologia Celular Prostática

Resumo

Smooth muscle (SM) is an important component of the prostatic stroma. We previously showed that, despite extensive morphologic changes, smooth muscle cells (SMCs) of the rat ventral prostate preserve some differentiation markers 21 days after castration. In the present study, we investigated whether the expression of SMC markers is preserved in the rat ventral prostate after long-term castration. Adult Wistar rats were castrated and sacrificed 100 days after surgery. The ventral prostates were processed for histology, stereology, immunocytochemistry (SM alpha-actin and SM-myosin heavy chain [MHC]), transmission electron microscopy (TEM), and reverse transcription polymerase chain reaction (smoothelin, sm22, and calponin). The prostates of castrated rats showed significant weight reduction, corresponding to only 5.6% of the control. Stereology showed that SMCs occupied the same proportion of the prostate volume but suffered a significant reduction in absolute volume (5.5% of control). The SMCs were retracted and showed spinous outlines. TEM revealed the presence of an abundant myofibrillar component, dense plaques, and an external lamina in these cells. SMCs were reactive to antibodies against SM alpha-actin and SM-MHC and expressed mRNA for smoothelin, sm22, and calponin. The results confirmed that rat prostatic SMCs are affected by androgen deprivation. Although showing marked phenotypic changes, these cells expressed SMC markers at the protein (SM alpha-actin and SM-MHC) and mRNA (smoothelin, sm22, and calponin) levels. These observations support the idea that SMCs may modulate their phenotypes (contractile vs synthetic) without changing their differentiation states. (AU)