The Effect of In Vitro Oxidative Stress on the Female Rabbit Bladder Contractile Response and Antioxidant Levels

Abstract

Introduction. There are several bladder dysfunctions that are associated with oxidative stress to the urinary bladder. Two experimental models are known to cause this type of bladder damage. The first is direct oxidative damage caused by hydrogen peroxide (H2O2). The second is oxidative damage caused by ischemia followed by reperfusion (I/R). The specific aim of this study is to directly compare these two models of oxidative stress. Methods. Six adult female NZW rabbits were divided into two groups of three rabbits each. Eight full thickness strips from three rabbit bladders were taken for in vitro ischemia/reperfusion physiological analysis, while eight strips from three rabbit bladders were taken for in vitro H2O2 physiological analysis. All tissue was analyzed for total antioxidant activity (AA) and malondialdehyde (MDA) levels. In addition, samples of the water baths were also analyzed for AA. Results. In vitro I/R reduced the response to field stimulation (FS) to a significantly greater extent than the inhibition of the response to carbachol. In vitro H2O2 decreased all responses to approximately the same degree. Total AA levels at higher concentrations of H2O2 for all bath fluids were significantly higher than controls. MDA levels were significantly elevated in both models of oxidative stress.