Autonomous Urinary Bladder Activity in Normal Man

The preceding paper 1 demonstrated in cat that the detrusor smooth muscle possesses autonomous rhythmicity, which develops as the bladder is filled and persists independently when the bladder is stripped of all known central and peripheral nervous connections. Like bladder tonus, 2 therefore, feline bladder rhythmicity had a non-neurogenic origin, which was principally changed by influences that altered the physical properties of the bladder wall. Vesical over-distention both dampened rhythmicity and lowered tonus, while chemical cystitis both enhanced rhythmicity and raised tonus. Reflex micturition was always preceded by rhythmic detrusor contractions. Since dampening rhythmicity raised the micturition reflex threshold and enhancing rhythmicity lowered the reflex threshold, it was hypothesized that autonomous detrusor contractions provide the necessary afferent stimulus, without which reflex micturition cannot occur. Before explaining human bladder function abnormalities by the animal experimental findings, it was important to determine whether there were important species differences in detrusor control