The effect of diltiazem on the healing of traumatic urethral inflammation

To investigate the effect of diltiazem, a calcium channel blocker, on healing of the traumatic urethral inflammation when applied systemically or locally.

21 adult male Wistar rats (230-250 g) were assigned to group 1 (n = 7) = control, group 2 (n = 7) = local application or group 3 (n = 7) = systemic application. In group 1, only a urethral injury was achieved at the 12-o'clock position by gently introducing and drawing a tiny hook in the urethra until urethral bleeding occurred. In group 2, after the same procedure, 10 mg/kg diltiazem was applied retrogradely via a 22-gauge Angiocath intraurethrally for 5 consecutive days, while the same account of the drug was administered intraperitoneally in group 3. After 21 days, the rats were sacrificed for urethrectomy. Pathologically, the thickness of connective tissue, the regularity of the epithelial lining, the presence of the inflammation and the density of collagen were evaluated with Masson's trichrome staining. The Mann-Whitney U test was used for statistical analyses.

The mean connective tissue thickness was 0.77 +/- 0.39, 1.01 +/- 0.77 and 0.93 +/- 0.53 microm in groups 1, 2 and 3, respectively. The differences between the groups were insignificant (p > 0.05). The hyperplastic epithelial lining in the study groups, with both systemic and local applications, was markedly infrequent and the inflammation was less prominent. However, these differences did not reach statistical significance.

Diltiazem appears not to have any preventive effect on connective tissue formation when applied locally or systemically in our urethral injury model.