Effect of severity and duration of bladder outlet obstruction on catalase and superoxide dismutase activity.

OBJECTIVES

To study the effects of partial bladder outlet obstruction on the cell's anti-oxidant defense mechanisms, superoxide dismutase and catalase, in order to elucidate how the bladder responds to oxidative stress.

METHODS

Four groups of eight rabbits were subjected to partial bladder outlet obstruction for 4, 8 and 12 weeks. Eight sham rabbits were used as the control group. The bladders were removed under anesthesia, and the muscle and mucosa were separated, frozen and stored at -80°C for analysis. Superoxide dismutase and catalase assays were carried out on these tissues. The groups were also categorized by severity (mild, intermediate and severe) of decompensation, as well as duration.

RESULTS

When separated by duration, catalase activity of the mucosa was significantly higher in the control and the 12-weeks obstructed rabbits. This activity was lower than the control in the 4- and 8-weeks obstructed rabbits. When separated by severity, catalase activity of the mucosa was significantly higher and severely decompensated than the muscle in the controls. When separated by duration or severity, superoxide dismutase activity of the muscle was significantly lower than controls for all obstructed rabbits. The activities of both superoxide dismutase and catalase were significantly reduced in the severely decompensated bladder smooth muscle, but not in the 12-weeks obstructed bladder smooth muscle.

CONCLUSIONS

Partial bladder outlet obstruction has significant effects on the activity of both superoxide dismutase and catalase in the bladder, with variations that are dependent on the severity and duration of the obstruction.