Objective      To explore the pathological features of recurrent urethral stricture tissues

and to observe the expression of transforming growth factor β1 (TGF-β1) and discuss its role and implication in the process of recurrent urethral stricture formation.       Methods       The urethral tissues were from 11 patients of recurrent urethral stricture and from 5 patients of brain death. Collagen fibers and elastic fibers were observed by Van Gieson staining

Verhoeff staining

Periodic acid Schiff staining in urethral tissue sections. TGF-β1 in urethral tissues was assessed by immunohistochemical method.       Results      In comparison with normal urethral tissues

the findings in recurrent urethral stricture tissues revealed that the normal cavernous body tissues were replaced by densely packed connective tissue fibers

collagen fibers increased and elastic fibers reduced. TGF-β1 staining in the tissues of the recurrent urethral stricture was found at the fibroblasts and endothelial cells of blood vessels

with its mean positive rate of 100% but only 20% in normal urethral tissues (P0.05).        Conclusion      Active proliferation of fibroblasts and over-deposition of extracellular matrix cause recurrent urethral stricture. High expression of TGF-β1 was related closely with the urethral hyperplastic scar. Inhibiting TGF-β1 could prevent and decrease the process of recurrent urethral stricture.