[Function and nerve growth factor of the rat urinary bladder during urethral obstruction and its relief]

It has been considered that the urethral obstruction influence the function and the nerve innervation of the bladder. In this study, the changes in the bladder function and the nerve growth factor (NGF) synthesized in the bladder were systematically analyzed both during partial urethral obstruction and after its relief in the rat. The maximum contraction pressure was temporally decreased and then increased 1.5 times of the normal level 6 week after the obstruction. NGF in the bladder, measured by ELISA method, was rapidly increased 5 times of the normal level 1 day after the obstruction. It gradually decreased 2 weeks after the obstruction but did not recover to the normal level. The maximum contraction pressure and the bladder NGF recovered to the normal level after the removal of 1 to 6 weeks obstruction. These results suggest that partial urethral obstruction reversibly increases the contractility and the NGF synthesis of the bladder.