Changes in urethral connective tissue after estrogen replacement therapy in ovariectomized rats.
OBJECTIVE
Genuine stress urinary incontinence is a common problem after the middle age. Various treatment modalities have been tried as a treatment for this entity and estrogens are one of the most common alternatives. Their effects on the urethral mucosa have been described in many studies, while the impact on the urethral connective tissue has been evaluated only in a few reports. In this study, we aimed to investigate the effect of estrogen on urethral connective tissue in ovariectomized rats.


METHODS
Thirty-six Wistar rats (4 months old, 250-300 g weight) were included in the study. They were organized as group 1 (ovariectomized, n = 10), group 2 (ovariectomized + late estrogen treatment, n = 10), group 3 (ovariectomized + early estrogen treatment, n = 10) and group 4 (sham operated, n = 6). Rats in group 1 were killed 6 weeks after the ovariectomy. Group 2 was ovariectomized 6 weeks before treatment and then received estradiol for 6 weeks. Group 3 was treated with estradiol for 6 weeks immediately after the ovariectomy. After killing the rats, urethral tissues were removed. Quantitative analysis of collagen fiber content was done by computerized image analyzer system in specimens stained with Masson's trichrome technique.


RESULTS
Percentages of collagen fiber content (mean +/- standard error of mean) were 58.4 +/- 5.9% in group 1; 53.3 +/- 4.8% in group 2; 46.3 +/- 3.4% in group 3 and 40.2 +/- 3.2% in group 4. There was not any significant difference among the groups (p > 0.05).


CONCLUSIONS
Our results suggest that early and late estrogen replacements do not seem to have a discriminating effect on the urethral connective tissue. Further studies are needed to assess the preventive effect of estrogen on urethra.
Department of Urology, Adnan Menderes University, Aydin, Ankara, Turkey. medundar@hotmail.com
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Dündar
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Koçak
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Erkuş
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Celasun
D000818:Animals; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D005260:Female; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D014521:Urethra / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism
D004958:Estradiol; D003094:Collagen