“On intraureteral pressure and its relation to the peristaltic movements of the ureter,” with demonstrations

By means of a cannula placed in the ureter and retained without ligatures, and which did not materially interfere with the peristalsis of the ureter, the intraureteral pressure and its relation to the peristaltic movements of the ureter were ascertained.

In nine experiments on dogs narcotized with morphin and atropin, the pressure in the ureter arose only to a minute degree, the average being a negative pressure, more pronounced under the influence of diuretics. In five, in which chloroform was used, the pressure was always positive; the irritability and contractility of the ureter were noticeably diminished. In six, under ether, the ureter was noted to be irritable and contractile three hours after the anesthesia was commenced; the pressure was low. In four, in which ether followed the administration of chloroform, ether showed a stimulating effect on the peristalsis, running the pressure rapidly down. In three, in which morphin and atropin, chloroform, and ether were successively tried during the same experiment, the specific effect of each as above noted was again observed. In an animal in which anesthesia was produced by decerebration, irritability and contractility of the ureter muscle were noted; the pressure was low, tending to negative on stimulating the ureter distal to the cannula. In one animal, anesthetized with cocain by the lumbar puncture method, the same results as with morphin were obtained. In two artificially constructed systems, which were demonstrated, phenomena analogous to those observed in the animals were produced and the causes indicated.

The experiments, which also were demonstrated in part, seem to justify the following deductions:

1. A suction normally follows the peristaltic wave of the ureter; at the same time a force is exerted on the fluid in front of the wave.

2. When the ureter is normally acting, the pressure in the pelvis of the kidney remains very low, fluctuating about a neutral point, this condition obtaining through the anatomical arrangement of the pelvis, which prevents it from collapsing under negative pressure. The rhythmic movements of the pelvis of the ureter effect a milking of the portion of the pyramid which projects into it.