Effects of Castration on Female Rabbit Bladder Physiology and Morphology

Objectives: To determine the effect of ovariectomy on bladder blood flow and oxygen tension. Women are subject to bladder dysfunctions that occur less frequently in men. These include interstitial cystitis (syndrome of urgency, frequency, and pain on distension), incontinence, and bladder infections. It is believed that alterations in female sex hormones play a major role in mediating these abnormalities. We believe that alterations in estrogen can have marked effects on the blood flow to the bladder.

Methods: We divided 20 female rabbits into two equal groups: ovariectomized and sham operated. Six weeks later, the bladder of each rabbit was evaluated for bladder capacity, compliance, permeability, blood flow, tissue hypoxia, morphology, and smooth muscle contraction.

Results: Ovariectomy resulted in decreased bladder compliance; decreased blood flow to the bladder mucosa and uterus, a smaller decrease in blood flow to the bladder smooth muscle, and mucosal hypoxia; and statistically significant thinning of the bladder mucosa and increased mucosal permeability.

Conclusions: Ovariectomy resulted in decreased blood flow and hypoxia to the bladder mucosa and a mildly decreased blood flow to the smooth muscle. The decreased blood flow and hypoxia may be related to the age-related uropathologic findings in postmenopausal women.