Structure and function of the rabbit bladder altered by chronic obstruction or cystitis.

Decreased muscle contractility has been observed in association with intercellular collagen deposition after acute urinary obstruction. Chronically induced (2 months) bladder neck obstruction in rabbits produced similar marked changes in the ultrastructure of the bladder wall, with widening of the intercellular spaces and formation of collagen. Resting intravesical pressure was greater in animals with bladder neck obstruction than in the controls, yet response to stimulation was not impaired. Bacterial cystitis, in contrast, produced no consistent change in ultrastructure but the response of intravesical pressure to pelvic nerve stimulation was reduced. It is concluded that intercellular collagen deposition is not responsible per se for impaired conduction of nerve stimuli; perhaps discrete conduction pathways exist in the detrusor and the intercellular electrotonic spread of action potentials is not essential for contraction.