RESUMO
PURPOSE: The aim of this study was to analyze the morphologic and morphometric changes in the urethra and vesical mucosa following hormonal replacement METHODS: We analyzed the changes in the urethra and vesical mucosa of 35 castrated adult female rats that had been subjected to estrogen and/or progestogen replacement. RESULTS: Estrogen replacement, whether or not accompanied with progestogen replacement, provoked metaplasia, hyperplasia and an increased occurrence of stratified epithelia. In the proximal urethra hypoestrogenism caused a higher occurrence of pseudo-stratified and transition epithelia, whereas in the urethral-vesical junction it caused a higher frequency of pseudo-stratified epithelia. The thickness of the epithelium increased following estrogen replacement whereas only a trend towards an increase of the propria lamina thickness was identified. Nuclear volume was only altered in the bladder epithelium. CONCLUSION: Estrogen replacement acted both morphometrically and morphologically on the lower urinary tract.