Motility of the urinary bladder in cats during filling at physiological rates. III. Spontaneous rhythmic bladder contractions in the conscious and anesthetized animal. Influence of distension and innervation.

Abstract

Spontaneous rhythmic bladder contractions were studied in conscious and anesthetized cats. Rhythmic activity was absent in the awake state, but appeared during deep relaxation or sleep. Usually, marked rhythmic bladder activity was present in the anesthetized cat, showing a differentiated reaction to distension. In response to physiological filling rates and various bladder volumes the spontaneous rhythmic contractions of the intact bladder had a frequency of 1-4/min, amplitudes up to 20 cm H2O (majority between 5-15 cm H2O) and a duration of 10-20 sec. The smallest increase in the rate of filling necessary to cause a rise in frequency was 0.08 ml/min (~1.5 hour-diuresis). When the entire collecting phase was recorded during a gradual rise in filling rate, a typical pattern often occurred. The first response of the rhythmic contractions was a rise in amplitude followed by increased frequency. Towards the micturition the amplitude decreased while the frequency continued to increase. The volume threshold of...