AT expression in human urethral stricture tissue.

BACKGROUND

Urethral stricture has a high recurrence rate. There is a common doctrine stating that "once a stricture, always a stricture". This fibrotic disease pathophysiology, pathologically characterized by excessive production, deposition and contraction of extracellular matrix is unknown. Angiotensin II type 1 (AT) receptor primarily induces angiogenesis, cellular proliferation and inflammatory responses. AT receptors are also expressed in the fibroblasts of hypertrophic scars, whereas angiotensin II (AngII) regulates DNA synthesis in hypertrophic scar fibroblasts through a negative cross talk between AT and angiotensin II type 2 (AT) receptors, which might contribute to the formation and maturation of human hypertrophic scars.

OBJECTIVE

This study was conducted to determine the expression of AT receptors in urethral stricture tissues.

METHODS

Urethral stricture tissues were collected from patients during anastomotic urethroplasty surgery. There were 24 tissue samples collected in this study with 2 samples of normal urethra for the control group. Immunohistochemistry study was performed to detect the presence of AT receptor expression. Data were analyzed using Mann-Whitney test, and statistical analysis was performed with SPSS version 20.

RESULTS

This study showed that positive staining of AT receptor was found in all urethral stricture tissues (n=24). A total of 8.33% patients had low intensity, 41.67% had moderate intensity and 50% had high intensity of AT receptors, while in the control group, 100% patients had no intensity of AT receptors. Using the Mann-Whitney test, it was found that urethral stricture tissue had a higher intensity of AT receptors than normal urethral tissue with a -value = 0.012.

CONCLUSION

The results showed that AT receptor had a higher intensity in the urethral stricture tissue and that AT receptor may play an important role in the development of urethral stricture.