Photodynamic therapy of rat bladder and urethra: evaluation of urinary and reproductive function after inducing protoporphyrin IX with 5-aminolaevulinic acid

Objective To assess the urinary and reproductive function of rats after inducing protoporphyrin IX with 5-aminolaevulinic acid (ALA) and subsequent intraurethral photodynamic therapy (PDT). Materials and methods Twelve female Wistar rats were given ALA orally or intravesically (four each), followed by intraurethral PDT through a 10-mm cylindrical fibre at 100 mW for 500s (argon laser, 632 nm). Urinary frequency, the number of gestations and histological changes were then evaluated and compared with a group of eight control rats. Results There was only a slight increase in urinary frequency during the first 2 weeks after PDT in the group given oral ALA, while the same degree of urinary frequency was evident for up to 4 weeks in those given intravesical ALA. Despite the occurrence of urinary incontinence from undefined causes in two rats, reproductive function remained unchanged. There was no histological evidence of damage to the reproductive system adjacent to the bladder. Conclusions PDT of the urethra with ALA is relatively safe and carries few risks of inducing permanent urological complications.