Nitric oxide synthase expression in neurogenic bladder disease: a pilot study

Neurogenic bladders are susceptible to bladder cancer development, especial ly in the case of chronic indwelling catheters. The classic carcinogenesis theory involves the formation of carcinogenic nitrosamines by bacteria due to chronic infection. We designed a pilot study to evaluate the expression of the of Nitric Oxide Synthase (NOS) isoforms in bladder tissue to study the role of the endogen ous formation of NO (Nitric Oxide) in neurogenic bladders. Immunohistochemistry was performed on bladder biopsies front neurogenic, no rmal, and obstructed bladders. The neurogenic bladder had a higher expression of endothelial NOS (eNOS), b ut especially of neuronal NOS (nNOS). Besides, this extra-neuronal expressi on of nNOS by urothelium and interstitial cells was observed. This study proves the important role of endogenous formation of NO by subur othelial nerves but also by urothelium and interstitial cells. This overexp ression could possibly be a factor in the higher incidence of bladder cance r in neurogenic bladders. On the other hand, it shows the plasticity of the NO pathways in these cases and raises important research questions concern ing the physiological role of these changes.