Agradecimentos: The authors thank the Electron Microscopy Center (Institute of Biosciences, UNESP, Botucatu, SP) for the transmission electron microscopy protocol procedures and for the use of Phillips electron microscope. This work was funded by FAPESP (São Paulo State Research Foundation; grants...

Agradecimentos: The authors thank the Electron Microscopy Center (Institute of Biosciences, UNESP, Botucatu, SP) for the transmission electron microscopy protocol procedures and for the use of Phillips electron microscope. This work was funded by FAPESP (São Paulo State Research Foundation; grants 06/60114-6, to S.L.F. and 06/60115-2, to F.K.D); by FUNDUNESP (Foundation for Development of Univ Estadual Paulista), by CNPq, and by CAPES do Brazil. This paper represents part of the PhD thesis presented by F.K.D. to the University of Campinas—UNICAMP, Brazil

Aims
To gain new insights into the molecular mechanisms of action of doxazosin, we investigated the prostatic stroma ultrastructure and the expression of genes involved with fibrosis, such as collagen type I and III (COL1A1 and COL3A1, respectively) and TGF-beta 1, in the rat ventral...

Aims
To gain new insights into the molecular mechanisms of action of doxazosin, we investigated the prostatic stroma ultrastructure and the expression of genes involved with fibrosis, such as collagen type I and III (COL1A1 and COL3A1, respectively) and TGF-beta 1, in the rat ventral prostate.
Main methods
Adult Wistar rats were treated with doxazosin (25 mg/kg/day), and the ventral prostates were excised at 7 and 30 days after treatment. Untreated rats were controls. Ventral prostates were subjected to ultrastructural, immunohistochemical, biochemical and molecular analyses.
Key findings
Doxazosin-treated prostates showed thickened bundles of collagen fibrils, activated fibroblasts, enlarged neurotransmitter vesicles and increased tissue immunostaining for collagen type I and type III when compared to untreated prostates. After 7 and 30 days of doxazosin treatment mRNA expression of COL1A1 and COL3A1 was significantly increased and reduced, respectively, compared to the control group. TGF-beta 1 mRNA and protein levels were increased after 7 days of doxazosin treatment, whereas only mRNA levels remained increased after 30 days of treatment.
Significance
Our data suggest that relaxation of smooth muscle cells by alpha-blockers interferes with the mechanical dynamics of the prostatic stroma extracellular matrix components, generating a pro-fibrotic effect probably via the TGF-beta 1 signaling pathway. Long term treatment with doxazosin may also lead to a reduced turnover of extracellular matrix components. Our results add to a better understanding of the molecular mechanisms behind the effects of alpha-blockade on prostatic histoarchitecture and the response to treatment for benign prostatic hyperplasia

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

06/60114-6; 06/60115-2

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