Morphometric analysis of the urethra of castrated female rats treated with tamoxifen

Abstract Objectives The aim of this study was to evaluate the effects of tamoxifen on the weight and thickness of the urethral epithelium of castrated female rats. Methods Forty castrated adult female Wistar–Hannover rats were randomly divided into two groups: Group I ( n  = 20) in which the animals received only the vehicle (propylene glycol) and Group II ( n  = 20) in which the rats received tamoxifen 250 μg/day by gavage. After 30 days of treatment, all animals were sacrificed and the urethra was immediately removed for weighing. Next, the urethra was divided into the proximal and distal segments, which were fixed in 10% formaldehyde and submitted to routine histological techniques for morphometric study. The data were analyzed using the weighted minimum mean-square error method and Student's t -test for two independent samples ( p Results There was a significant increase in the mean weight of the urethra in the rats of Group II compared to the control group, 32.0 ± 2.0 mg and 22.0 ± 1.6 mg, respectively ( p p p  = 0.514). Conclusion Treating castrated adult rats with 250 μg/day of tamoxifen for 30 days may increase the weight of the urethra and the thickness of the distal urethral epithelium.