Effects of combined estrogen and progesterone replacement treatment on detrusor contractility and histology in oophorectomized rats

Abstract

Aim:The aim of this study was to investigate the effects of estrogen plus progesterone treatment administered after surgical menopause on morphological and muscarinic receptor sensitivity in detrusor muscle bands of rats. Materials and Methods: A total of 40 female Albino-Wistar rats were assigned into two groups to undergo surgical menopause with sham operation (n = 10) and bilateral oophorectomy (n = 30). Thirty oophorectomized rats were assigned into three groups for different treatments administered for 8 weeks beginning from the 7th postoperative day. At the end of the 8th postoperative week, laparotomy was performed in all of them and the urinary bladders were excised and investigated with light microscope. All statistical analysis and graphs were performed using GraphPad Prism version 4. P < 0.05 was considered to be statistically significant. Results: It was determined that average bodyweights were increased to some extent in oophorectomized and sham groups after treatment and while it was more marked in the group receiving estrogen therapy, bodyweights were decreased in the group receiving estrogen plus progesterone therapy. However, this was not statistically significant. No statistically significant difference was determined between the sham, placebo and 17-b estradiol treatment groups regarding contractile response of urinary bladder tapes to carbachol (P > 0.05). Contractile responses of urinary bladder tapes of the estrogen plus progesterone treatment group were found to be statistically lower than the placebo group (P < 0.05). Conclusion: Our in vitro findings demonstrate that treatment with estrogen plus progesterone decreases muscarinic activity in oophorectomized rats, whereas estrogen-only treatment does not. Our study establishes the basis for further studies to answer whether combination of estrogen and progesterone treatment can restore detrusor overactivity associated with sex hormone defects seen at menopause.

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

“…Progesterone stimulates formation of epidermal growth factors, secretes epidermal growth factors and induces growth of epithelial cells . Etiz et al . reported that combined treatment with both P4 and estrogen is better than simple treatment with only estrogen for recovery of detrusor muscle contraction in a study assessing contraction of the detrusor muscle in an ovariectomy rat model after combined treatment with both estrogen and P4; however, a study of 483 menopausal women by Hextall et al .…”

“…Progesterone stimulates formation of epidermal growth factors, secretes epidermal growth factors and induces growth of epithelial cells. 19 Etiz et al 7 reported that combined treatment with both P4 and estrogen is better than simple treatment with only estrogen for recovery of detrusor muscle contraction in a study assessing contraction of the detrusor muscle in an ovariectomy rat model after combined treatment with both estrogen and P4; however, a study of 483 menopausal women by Hextall et al 20 reported that urinary symptoms worsened during menstruation when P4 functioned as the predominating hormone. Another study showed that urinary incontinence symptoms of stress and urgent urine worsened when menopausal women with menopause were given both estrogen and P4.…”

“…Progesterone, often a part of hormone therapy, acts as a partial antagonist of estrogen . In other studies, estrogen–P4 administration resulted in decreased bladder muscle contractions compared to oral administration of estrogen involving ovariectomized rats for 8 weeks …”

“…6 In other studies, estrogen-P4 administration resulted in decreased bladder muscle contractions compared to oral administration of estrogen involving ovariectomized rats for 8 weeks. 7 Thus, a combined therapy of estrogen and P4 can reduce bladder muscle contractions, which can occur with decreased secretion of sex hormones as a result of ovariectomy.…”

Ovarektomize Dişi Sıçanlarda 1,1-Dimetilbiguanit Hidroklorid (Metformin)'in Detrüsör Kas Kontraktil Yanıtı Üzerine Etkileri

“…Thus, HRT is used in postmenopausal women with urinary tract dysfunction (10). HRT can considerably affect the bladder function by changing detrusor innervation and vascular density and distribution of receptor density, smooth muscle size and connective tissue density (22,23). At the same time, HRT is reported to improve the contractile response of the detrusor to carbachol (23).…”