Effect of ovariectomy, 17-beta estradiol, and progesterone on histology and estrogen receptors of bladder in female partial bladder outlet obstruction rat model

Abstract

Aim The aim of this study was to investigate the effect of bilateral ovariectomy (OVX), 17-beta estradiol (E2), and progesterone (P4) on the histology and estrogen receptor (ER) expression of the bladder using a female partial bladder outlet obstruction (pBOO) rat model. Material and Methods A total of 60 female Sprague-Dawley rats were evenly assigned into six groups of 10 each. Group A served as the control. Groups B-F underwent induced pBOO. Groups C-F underwent OVX. Groups D-F were given E2 (0.1mg/kg/day), Group E was given P4 (1mg/kg/day), and Group F was given P4 and dehydroepiandrosterone (DHEA) (300g/kg/day) by an Alzet pump. Four weeks later, serum E2 and P4 levels were evaluated. Each rat was anesthetized and the urinary bladder was removed for weighing and histological study. Results Expression of ER- was not significantly different between the control group and the other study groups. pBOO was shown to increase both bladder weight and detrusor muscle thickness. OVX had an additive effect to BOO on increased blood vessel density in the bladder. E2 was shown to increase blood vessel density, while P4 supplementation decreased blood vessel density. DHEA did not cause any significant effects on blood vessel density. Conclusion Hormone therapy did not change the expression of ER in bladder outlet obstruction. Estradiol stimulated the increased angiogenesis of the bladder detrusor but P4 decreased the angiogenesis of the bladder detrusor. DHEA had no effect on the bladder detrusor.