Effects of ovariectomy and oestrogen replacement on the function and expression of Rho-kinase in rat bladder smooth muscle.
BJU Int
; 98(5): 1114-7, 2006 Nov.
Article
em En
| MEDLINE
| ID: mdl-17034613
ABSTRACT
OBJECTIVE:
To investigate the effects of ovariectomy and oestrogen replacement on the function and expression of Rho-kinase in rat bladder smooth muscle, as the actual effects of oestrogen deprivation on bladder smooth muscle are unclear. MATERIALS ANDMETHODS:
Female Sprague-Dawley rats were placed into one of three groups sham-operated, bilateral ovariectomy-only, and bilateral ovariectomy plus oestrogen replacement groups. In the last group, oestrogen was replaced by weekly injection of beta-estradiol 17-cypionate (250 microg/kg subcutaneously for 6 weeks) beginning at 1 week after ovariectomy, whereas the other groups received vehicle-only injections for 6 weeks. After treatment, the bladder was removed for muscle strip studies to evaluate the effects of Y-27632, a specific inhibitor of Rho-kinase, on baseline tension and carbachol-induced tonic contractions. Also, the protein expression of RhoA and Rho-kinase isoenzymes was assessed by Western blot analysis.RESULTS:
Of the three groups, incubation with 10 microm Y-27632 resulted in the largest decrease in baseline tension of strips from the bilateral ovariectomy-only group, but this was not statistically significant (P > 0.05). For carbachol-induced tonic contractions, strips from the bilateral ovariectomy-only group were attenuated the most among the three groups after adding Y-27632 (P < 0.05). However, there were no significant differences in the levels of RhoA and the two Rho-kinase isoenzymes in bladder tissues from the three groups.CONCLUSION:
Our data show that oestrogen might inhibit the function of Rho-kinase in bladder smooth muscle, while having no significant effect on its expression. This finding might help to explain the greater incidence of urinary tract symptoms suggestive of overactive bladder after the menopause in women.
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Base de dados:
MEDLINE
Assunto principal:
Bexiga Urinária
/
Ovariectomia
/
Terapia de Reposição de Estrogênios
/
Proteínas Serina-Treonina Quinases
/
Peptídeos e Proteínas de Sinalização Intracelular
/
Músculo Liso
Limite:
Animals
Idioma:
En
Revista:
BJU Int
Assunto da revista:
UROLOGIA
Ano de publicação:
2006
Tipo de documento:
Article