Cystometric evaluation of early and late irradiation damage to the mouse urinary bladder.

The present study reports a simple, non-invasive, in vivo method for detecting early and late radiation damage to the mouse urinary bladder using transurethral bladder filling. The study also describes a useful experimental model for irradiation of mouse urinary bladder without any concomitant irradiation of the rectum and bony structures and maximal shielding of the small intestine. Within 30 days after single fraction bladder irradiation at 5-30 Gy, repeated cystometric investigations reveal a change in the reservoir function of the bladder illustrated by a considerable dose-dependent decrease in the compliance of the bladder wall. The changes in the reservoir function is reversible hence the bladder function is restored after another month. At various time intervals after the irradiation, however, the late radiation damage appears, the time of manifestation being dose-dependent. This final change is irreversible and consistent with the clinically known contracted bladder.