Serial changes in proximal urethral function after transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in a canine model.
We performed transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in 6 mongrel dogs. To evaluate the changes in proximal urethral function after TUBAL-H, the urethral cross sectional area (CSA, cm2) and urethral pressure (Pu, cmH2O) were measured using a balloon probe that allows their simultaneous measurement, and the urethral compliance (Comp, cm3/cmH2O) was calculated from these parameters and serially evaluated. In addition, the changes in Pu, CSA and Comp after administration of an alpha-adrenoceptor antagonist were evaluated before and 16 weeks after TUBAL-H. Before TUBAL-H, the mean Comp was 0.013, and the mean maximum CSA (MCSA) was 0.66. Eight weeks after TUBAL-H, the mean Comp was 0.038, and the mean MCSA was 1.39, showing a significant increase (p < 0.01). Sixteen weeks, after TUBAL-H, the mean Comp was 0.026, and the mean MCSA was 1.21, being lower than those at 8 weeks after TUBAL-H, but significantly higher than those before TUBAL-H (p < 0.05). After administration of the alpha-adrenoceptor antagonist, phentolamine (1 mg/kg), before TUBAL-H, the mean Comp significantly increased to 0.046 (p < 0.05), and the mean MCSA to 1.40 (p < 0.01). The mean Comp was significantly increased to 0.033 (p < 0.05), by phentolamine administration 16 weeks after TUBAL-H, but no other changes were observed. After TUBAL-H, urethral elasticity increased, and this increase persisted for 4 months. The responses of Comp and MCSA to alpha-adrenoceptor antagonist administration before and 16 weeks after TUBAL-H suggested that part of the effects of TUBAL-H is due to damage to alpha-adrenoceptors.
Kurokawa
K
K
Department of Urology, Gunma University School of Medicine.
Suzuki
T
T
Suzuki
K
K
Fukabori
Y
Y
Imai
K
K
Yamanaka
H
H
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D002404:Catheterization; D003187:Compliance / Q000187:drug effects; D004285:Dogs; D006979:Hyperthermia, Induced / Q000379:methods*; D053685:Laser Therapy; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha; D014521:Urethra / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha; D010646:Phentolamine