The Effect of Nerve Growth Factor and Vanilloid Receptor Subtype 1 on Bladder Function after Relief of Bladder Outlet Obstruction in Rats / 대한비뇨기과학회지

ABSTRACT

PURPOSE: This study was performed to investigate the changes in nerve growth factor (NGF), and vanilloid receptor subtype 1 (VR1), after the relief of bladder outlet obstruction, and to look at how these changes participate in functional changes of the bladder. MATERIALS AND METHODS: 50 Wistar male rats, weighing approximately 250-300g, were used for this study, and divided into two groups 10 controls and 40 experimental. The control group consisted of sham operated animals. The experimental group was obstructed for 3 weeks by partial urethral ligation. After 3 weeks, the obstruction was relieved by urethral deligation. Cystometrograms (CMG) were performed 3 weeks after deligation. On the basis of CMG, the experimental group was subdivided into normalised, and unstable, bladder groups. The bladders of each group were dissected out, weighed and immunohistochemical staining for NGF and VR1 analysis, performed. RESULTS: Compared with the control group, bladder weights of the normalised, and unstable, bladder groups were increased (p<0.05). On CMG, there was no significant difference in contraction pressure among the 3 groups. The contraction interval of the unstable bladder group was markedly decreased compared with that of the control and normalised groups. On immunohistochemical staining, contrary to the control and normalised groups, the intensity of staining for NGF in the unstable bladder group increased in the basal layer, submucosa and interfascicular layers. VR1-immunoactive nerve fibre-like structures were seen in the basal and submucosal layers in the unstable bladder group, and there were no VR1-like structures in the muscle layer. However, there were no VR1-like structures any of the layers of the control and normalised groups. CONCLUSIONS: Increased NGF and VR1 may be related to persistent unstable bladder or bladder irritative symptoms after rectifying a bladder outlet obstruction.