PATHOGENESIS OF ACUTE RADIATION EFFECTS IN THE URINARY-BLADDER - EXPERIMENTAL RESULTS

Purpose: The present review summarizes experimental studies of the pat hogenesis of acute radiation-induced changes in urinary bladder functi on. Material and Methods: Transurethral cystometry was used for longit udinal assessment of bladder function in mice. With this technique, ra diation-induced changes in storage capacity can be quantified. In hist ological studies, changes in urothelial cell density and in urothelial protein expression during the acute radiation response were determine d. Acetylsalicylic acid (ASA) was used for the treatment of acute func tional changes. Results: The histological studies did not reveal any s ystematic fluctuations in urothelial cell density during the time of t he acute radiation response. However, characteristic changes in the ex pression of proteins associated with urothelial cell function, differe ntiation and cell contact were observed, which correlated with the fun ctional impairment. By local or systemical application of ASA, a signi ficant restoration of bladder function compared to placebo treatment c ould be achieved. Conclusion: Acute functional radiation effects in th e urinary bladder are not based on urothelial denudation. However, cha nges in protein expression indicate an impairment of the urothelial ba rrier function. The results of ASA treatment demonstrate that prostagl andins are involved in the response. Alterations in urothelial or endo thelial prostaglandin metabolism may be primarily radiation-induced or secondary because of the impaired urothelial barrier.