Changes in urethral connective tissue after estrogen replacement therapy in ovariectomized rats

[Role of estrogens in lower urinary tract physiology and physiopathology]

GOAL

The aim was to review the literature on estrogens and lower urinary tract.

MATERIAL

A review of literature through the PubMed library until December 31, 2012 was carried out using the following keywords: lower urinary tract, bladder, urethra, nervous central system, innervation, female, women, estrogen, estradiol, urogenital atrophy, urinary incontinence, overactive bladder, urinary tract infection.

RESULTS

On the bladder, estrogens are involved in the trophicity, vascularisation, alpha-adrenergic, cholinergic and muscarinic receptor density, detrusor contractility and inflammation. On the urethra, they impact vascularisation, contractility, urethral pulse and tone, anatomical and functional length. On the neurological control, they act on capsaicin-sensitive afferent fibres, neurological regeneration, nerve growth factor expression and viscerovisceral sensitisation.

CONCLUSION

Estrogens play a major role on the lower urinary tract physiology and physiopathology both on the urethra and the bladder.

Immunohistochemical analysis of collagen types I, III, IV and α-actin in the urethra of sexually intact and ovariectomized beagles

Urinary incontinence is a widespread problem in both postmenopausal women and ovariectomized dogs. The objective of this study was to investigate the influence of ovariectomy on the immunoreactivity and the distribution pattern of collagens I, III, IV and alpha-actin in the canine urethra. The immunohistochemical results were evaluated in five sexually intact and five ovariectomized beagles. The immunostaining of both collagens I and III delineated urethral connective tissue fibres and co-localized within in the fibres of both groups. The basement membranes of smooth muscle cells and sinusoids showed marked type IV collagen expression, whereas only faint immunoreactivity was present at the urothelial-stromal interface. No differences could be detected in the expression or distribution of the assessed collagen types and actin between ovariectomized and control animals. In conclusion, ovariectomy does not appear to have an effect on urethral collagens I, III, IV and smooth muscle actin in the dog, as ascertained by immunohistochemistry.

Endocrine status and markers of collagen synthesis and degradation in serum and urogenital tissue from women with and without stress urinary incontinence

AIMS

To investigate possible differences in androgen/estrogen status between patients with stress urinary incontinence (SUI) and healthy women's and to study possible associations between circulating estrogens and androgens on the one hand and collagen synthesis and metabolism in urogenital tissue on the other.

METHODS

Markers of collagen turnover, the carboxy-terminal propeptide of type I procollagen (PICP), the carboxy-terminal telopeptide of type I collagen (ICTP), and the amino-terminal propeptide of procollagen III (PIIINP), were assayed in urogenital tissue homogenates and estradiol-17beta (E2), total testosterone (T), and sex-hormone-binding globulin (SHBG) were assayed in peripheral serum from 58 patients with SUI and 30 urologically healthy women. Apparent concentrations of free testosterone (fT) were calculated from T, SHBG, and a fixed albumin value.

RESULTS

Significant positive correlations were found between E2 and PICP in controls and between E2 and ICTP in SUI patients without exogenous hormones. Significant negative and sometimes strong correlations were found between serum T and fT on the one hand and all three collagen turnover markers on the other. These correlations were strengthened when parity and/or body mass index (BMI) were reduced. No correlations between T and fT and collagen turnover markers were found in the controls. There were no significant differences between any of the groups in serum E2, T, or fT.

CONCLUSION

Estrogens may increase collagen turnover in urogenital tissue, however, the clinical significance of this is still unclear. Androgens may affect urogenital tissue negatively by slowing down collagen turnover, probably by inhibition of matrix metalloprotease (MMP) synthesis and/or activity. Urogenital tissue in SUI patients and in urologically healthy women may differ in androgen sensitivity.

Benefit and safety of 28-day transdermal estrogen regiment during vaginal hysterectomy (a controlled trial)

OBJECTIVES

Assessment of benefit and safety of 28-day transdermal 17-beta estradiol regimen during vaginal hysterectomy.

METHODS

Two-hundred and sixty-nine postmenopausal women, undergoing vaginal hysterectomy were divided into: transdermal estrogen hormone replacement therapy (TEHRT) group (n=119) with 28-day transdermal 17-beta estradiol 50 mg/day, 14 days before and after operation; and vaginal estrogen hormone replacement therapy (VEHRT) group (n=150) with 14-day preoperative vaginal conjugated estrogen 0.625 mg/day. The effect on: endometrium, wound healing, infection, recurrent organ prolapse were evaluated.

RESULTS

Pain symptoms, vaginal fetid discharge, swelling, crusting (p<0.001); visible wound opening on the 4 week control (p<0.01); patient assessment of outcome (p<0.001) were in favor of TEHRT. On the fifth postoperative day, VEHRT group showed: higher leukocytes increase (p<0.01); more patients with leukocytes count higher than 15x10(9) L(-1) (p<0.001) and afternoon body temperature higher than 38 degrees C (p<0.01). On the last follow-up control (VEHRT--28.3 months and TEHRT--24.5 months) TEHRT group had more patients with stage 0 of the apical segment (p<0.05). Point C was higher and total vaginal length longer in TEHRT group (p<0.01; p<0.05). Frequency, constipation, painful coitus, incontinence during intercourse were more frequent in VEHRT (p<0.001; p<0.05; p<0.05; p<0.05). Endometrium with a thickness between 2 and 4 mm, was more frequent in the TEHRT group (p<0.05). There were no significant differences in occurrence of more thickened endometrium and more significant morphological changes (endometrial polyp, simplex hyperplasia) between the groups. In none of the patients from the both study groups complex hyperplasia, atypical hyperplasia or endometrial carcinoma were observed.

CONCLUSIONS

The 28-day transdermal 17-beta estradiol regimen seems to be safe and effective procedure.

Markers of collagen synthesis and degradation in urogenital tissue from women with and without stress urinary incontinence

AIMS

Multiparity and obesity are risk factors for stress urinary incontinence (SUI), but collagen synthesis and metabolism in the urogenital tissue itself may also affect its function and control of micturition. Whether changes in synthesis or degradation of collagen are part of the etiology of SUI is not known and published studies show diverging results. The aims of the present study was to investigate collagen turnover in urogenital tissue in women with SUI (n=71) and in urologically healthy women (n=31).

METHODS

Markers of collagen synthesis and breakdown, the carboxy-terminal propeptide of type I procollagen (PICP), the carboxy-terminal telopeptide of type I collagen (ICTP), and the amino-terminal propeptide of procollagen III (PIIINP) were assayed in urogenital tissue homogenates and peripheral serum.

RESULTS

In the total clinical material SUI patients were significantly older, had a significantly higher body mass index (BMI) and significantly lower serum PICP and tissue ICTP levels than the controls. When healthy controls were compared with SUI patients matched for age, BMI, parity, and hormonal/menopausal status (31 women in each group), the SUI patients had significantly lower serum concentrations of PICP and significantly lower tissue concentrations of PIIINP and ICTP than the controls. Within the total material of SUI patients, post-menopausal women with weak and strong HRT and pre-menopausal women had significantly lower S-ICTP concentrations than untreated post-menopausal patients. Significant negative correlations to parity were found for T-PIIINP and T-PICP and to BMI for T-ICTP.

CONCLUSIONS

The low tissue collagen marker levels in women with SUI suggest a reduced collagen turnover, which may negatively affect tissue strength and elasticity.