Background: Urethral stricture disease is an obstruction or thinning of the urethra that causes restriction of urinary flow from the bladder during micturition. The object of the present study was to evaluate the effectiveness of the proteolytic enzyme metalloproteinase-1 as treatment in urethral stricture disease.
Methods: An experimental study was carried out on rabbits in which urethral stricture was created endoscopically by cauterization. The rabbits were divided into three study groups. Metalloproteinase-1 was applied endoscopically in Group 1; phosphate-buffered saline solution was applied in Group 2; and Group 3 was the control group without stricture that received no treatment. The animals were euthanized after 25 days and histopathological slices of the strictured and control regions were stained with Masson's trichrome stain to quantify mean collagen concentration by means of densitometry. Student t test was used to compare the two different groups with parametric variables, and analysis of variance was used to compare more than two groups.
Results: Collagen concentration analysis in the three groups showed a statistically significant difference with P = 0.012 with two degrees of freedom. In the analysis among groups, there was a statistically significant difference that showed the metalloproteinase-1 group had lower collagen concentration than the phosphate-buffered saline group P = 0.009. Urethral opening area in the metalloproteinase-1 group was found to be larger than that in the phosphate-buffered saline group P = 0.048.
Conclusions: Metalloproteinase-1 protein application in strictured urethral tissue is effective in reducing collagen concentration and maintaining or enlarging urethral opening.