In vivo measurement of force in the ureter. 2. Influence of urinary flow.

By means of a newly developed measuring catheter the occluding force of the ureter under changing diuresis conditions was investigated using 12 canine ureters. Even under extremely high flow rates of some 50 times normal values, the ureter returned after short phases of noncoaptive transport to active bolus transport. No direct connection between flow rate and basal pressure on the one hand and the form of transport on the other hand was observable. Only after prolonged continuous loading on the ureter with high flow rates was a loss of occluding forces observed with the noncoaptive form of transport, then taking on more significance.