Cyclical estrogen and free radical damage to the rabbit urinary bladder.

Introduction and Hypothesis: There are a number of lower urinary tract dysfunctions (LUTD) that occur primarily in women. Our hypothesis is that cyclical estrogen will produce LUTD in part by the generation of free radicals and oxidative damage to cellular and subcellular membranes.
Methods: Twenty female rabbits were divided into five groups: control, ovariectomized (Ovx), Ovx receiving continuous estrogen, Ovx receiving cyclical estrogen ending off estrogen, and Ovx receiving cyclical estrogen ending on estrogen. Statistical analyses used ANOVA followed by the Tukey analysis for individual differences.
Results: High estrogen increased bladder mass, contraction, compliance, and blood flow and decreased oxidative damage. Low estrogen decreased bladder mass, contraction, compliance, and blood flow and increased oxidative damage.
Conclusions: The decreased blood flow associated with increased oxidative damage demonstrates that cyclical damage to cellular membranes occurs. This supports the hypothesis that cycling estrogen may play a role in the etiology of LUTD of women.