Vascular endothelial growth factor expression in the urethral epithelium of castrated adult female rats treated with tamoxifen

Objective. The aim of this study was to evaluate the effects of tamoxifen on vascular endothelial growth factor (VEGF) expression in the urethral epithelium of castrated rats. Materials and methods. Thirty-six adult, castrated, female Wistar-Hannover rats were randomly divided into two groups: group I (n = 16, control), receiving only propylene glycol, and group II (n = 20, tamoxifen), treated with 250 mu g/day of tamoxifen for 30 consecutive days by gavage. On the 31st day, the animals were sacrificed and the urethras were immediately removed, separated into the proximal and distal segments and processed for VEGF immunohistochemistry. The data were analysed using Student's t-test (p < 0.05). Results. The mean percentage of VEGF expression in the epithelium of the proximal urethra of the animals in groups I and II was 64.47 +/- 3.70 and 74.69 +/- 3.03, respectively (p < 0.03), whereas the mean percentage of VEGF expression in the distal urethral epithelium of the animals in groups I and II was 53.49 +/- 4.64 and 68.57 +/- 3.67, respectively (p < 0.01). Conclusions. Our results indicate that, at the dose and during the time of treatment used, tamoxifen increased VEGF expression in the urethral epithelium of castrated rats.