Expression of CD44 and E-cadherin cell adhesion molecules in hypertrophied bladders during chronic partial urethral obstruction and after release of partial obstruction in rats

Abstract

Objectives To determine the functional changes in the bladder and the expression of adhesion molecules in bladder tissue during chronic partial urethral obstruction and after release of partial obstruction in rats. Methods Twenty-one male Sprague-Dawley rats were separated into three groups, each containing 7 rats. A sham operation was performed in group 1 and cystometry was done 6 weeks later. In groups 2 and 3, hypertrophied unstable bladders were developed by partial infravesical outflow obstruction during a 6-week period. After this period, cystometry was performed in all group 2 rats. In group 3, the ligature was removed, the rats were followed up for 6 weeks, and then cystometry was performed. After cystometric evaluation, the bladders in all the rats were removed, weighed, and studied immunohistopathologically. Results After release of infravesical outflow obstruction, the bladder weight, residual volume, bladder capacity, maximal voiding pressure, voiding amplitude, and bladder contraction time decreased and bladder compliance increased in group 3 compared with group 2. CD44 and E-cadherin expression in the interstitial space and uroepithelial bladder tissue in group 2 rats stained intensely compared with those of groups 1 and 3. Conclusions After release of 6 weeks of infravesical outflow obstruction, the cystometric parameters were significantly improved. Expression of CD44 and E-cadherin in the obstructed bladder tissue may be a pathologic sign of inflammation.