Effects of estrogen and progesterone on urinary bladder in female rabbit: Evaluation by quantitative morphometric analyses

Objectives. To investigate possible effects of estrogen and/or progesterone on the histologic characteristics of female rabbit urinary bladders, we ca rried out quantitative morphometric analysis of the rabbit bladders. Methods, Mature female rabbits were treated by ovariectomy with and without successive estrogen and/or progesterone administration, Area densities of the connective tissue (CT) and smooth muscle (SM) cells, the area of single SM cells, and the thickness of the bladder wall were determined by compute r-assisted quantitative morphometric analysis. Results. Six weeks after each treatment, ovariectomy alone resulted in a de crease in CT density of the bladder. Successive estrogen treatment increase d the bladder wet weight and SM cell density within the bladder wall. Proge sterone treatment reduced CT degradation in ovariectomized rabbits. Sex ste roids did not significantly influence the area of each SM cell. There was n o significant difference in histologic characteristics between the rabbits treated by estrogen alone and those treated by combination (estrogen and pr ogesterone) therapy. Conclusions. Ovariectomy and successive hormonal replacement therapy result ed in morphologic changes within the rabbit urinary bladder. Cotreatment wi th progesterone did not significantly change the morphologic findings produ ced by estrogen treatment alone. (C) 1999, Elsevier Science Inc. All rights reserved.