Effects of estrogen and tibolone on bladder histology and estrogen receptors in rats

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YANG Xin(Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing 100034, China)
LI Ya-zhen(Department of Respiratory, People's Hospital of Shenzhen, Guangdong 518020, China)
MAO Zhuo(Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing 100034, China)
GU Pei(Department of Obstetrics and Gynecology, Beijing Shijitan Hospital, Beijing 100038, China)
SHANG Ming(Department of Obstetrics and Gynecology, Beijing Friendship Hospital, Beijing 100050, China)
Journal Title:
Volume 122, Issue 04, 2009
Key Word:
estrogen; tibolone; bladder; estrogen receptor

Abstract: Background Estrogen deficiency causes atrophic changes within the urogenital tract, and is associated with urinary symptoms. The purpose of this study was to investigate the effects of estrogen and tibolone on bladder histology, and the changes of estrogen receptor α and β (ERα and β) protein expression in the detrusor muscle.Methods Forty female rats were separated into four groups of ten each. They received a sham operation (Sham), ovariectomy (Ovx), ovariectomy plus estrogen replacement (Ovx+E), or ovariectomy plus tibolone treatment (Ovx+T). After 12 weeks each rat was anesthetized and the bladders were removed. The bladders' ultra structure, collagen fiber (CF) to smooth muscle(SM) ratio and ER subtypes were studied. Statistical analyses were performed using the one-way analysis of variance test.Results Ovx resulted in significant degeneration in bladder ultra structure; however, estrogen and tibolone reversed those changes. Ovx increased the CF/SM ratio, estrogen and tibolone resulted in an increase. Two estrogen receptors (ERs) were expressed in the bladder detrusor, with ERβ the main subtype. Ovx resulted in up-regulation of ERα and down-regulation of ERβ. With estrogen and tibolone treatment, ERβ showed a significant increase but ERα showed no significant difference compared with Ovx.Conclusions Estrogen deficiency deteriorates bladder ultra structure and histology. Supplementary estrogen can improve bladder function which may be due to inhibition of collagen hyperplasia and increased SM density. ERβ has an important role in mediating estrogen function in the bladder. Tibolone has a mild estrogenic action and has an effect on bladder function and structure to some degree.

  • [1]Iosif CS,Batra S,Ek A,Astedt B.Estrogen receptors in the human femalelower urinary tract.Am J obstet Gynecol 1981; 141:817-820.
  • [2]Batra SC,Iosif CS.Progesterone receptors in the female lower urinary tract.J Urol 1987; 138:1301-1304.
  • [3]Iosif CS,Bekassy Z.Prevalence of genito-urinary symptoms in the late menopause.Acta Obstet Gynecol Scand 1984; 63:257-260.
  • [4]Rhodes A,Jasani B,Balaton AJ,Miller KD.Immunohistochemical demonstration of oestrogen and progesterone receptors:correlation of standards achieved on in house tumours with that achieved on external quality assessment material in over 150 laboratories from 26 countries.J Clin Pathol 2000; 53:292-301.
  • [5]Seidlova-Wuttke D,Schultens A,Jarry H,Wuttke W.Urodynamic effects of estradiol (E2) in ovariectomized (ovx) rats.Endocrine 2004; 23:25-32.
  • [6]Li YZ,Yang SL,Shang M,Wu Q,Liao QP.Effects of ovariectomy and estrogen replacement on bladder function and structure in rats.Chin J Obstet Gynecol (Chin) 2006; 41:826-829
  • [7]Elbadawi A,Yalla SV,Resnick NM.Structural basis of geriatric voiding dysfunction.Ⅱ.Aging detrusor:normal versus impaired contractility.J Urol 1993; 150 (5 Pt 2):1657-1667
  • [8]Prieto Chaparro L,Salinas Casado J,Barba Solana C,Resel Estevez L.Insufficient detrusor contractility:a urodynamic and morphologic entity in prostatism.Arch Esp Urol 1996; 49:727-739
  • [9]Aikawa K,SuginoT,Matsumoto S,Chichester P,Whitbeck C,Levin RM.The effect of ovariectomy and estradiol on rabbit bladder smooth muscle contraction and morphology.J Urol 2003; 170 (2 Ptl):634-637.
  • [10]Lin A,Levin R,Kogan B,Whitbeck C,Chichester P,Sokol R,Mannikarottu A.Estrogen induced functional hypertrophy and increased force generation of the female rabbit bladder.Neurourol Urodyn 2006; 25:473-479.
  • [11]Stirone C,Duckies SP,Krause DN0 Procaccio V.Estrogen increases mitochondrial efficiency and reduces oxidative stress in cerebral blood vessels.Mol Pharmacol 2005; 68:959-965.
  • [12]Makela S,Strauss L,Kuiper G,Valve E,Salmi S,Santti R,et al.Differential expression of estrogen receptors alpha and beta in adult rat accessory sex glands and lower urinary tract.Mol Cell Endocrinol 2000; 170:219-229.
  • [13]Taylor AH,Al-Azzawi F.Immunolocalisation of oestrogen receptor beta in human tissues.J Mol Endocrinol 2000; 24:145-155.
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