A recent report from this laboratory has shown that when the upper and lower segments of the sectioned ureter are communicated through a vinyl catheter (reconstructed ureter), the excitation is caused by urine flow at the connected part of the lower segment, independently of the upper segment, and the normal urine transporting ability is retained, judging from the myogram of ureter (S. Takahashi, Jap. J. Urol., 65(5), 303, 1974).
The primary purpose of the present experiment was to compare the action potentials and the pressure waves of the ureter which was sectioned transversely at the central part and reconstructed between the upper segment and the ureteral orifice (reversely connected ureter) with those of the intact ureter and the reconstructed ureter.
In this experiment, 16 ureters from 8 mongrel dogs were used: first of all, 16 intact ureters were used as control, and then surgery was performed to make a reversely connected ureter in which urine was allowed to pass reversely from the ureteral orifice to the kidney.
The results obtained are as follows: 1) in all control ureters, the peristalsis was observed with a concomitant appearance of pressure waves, except 1 which showed antiperistalsis; 2) in the reversely connected ureters (16), 13 showed anti-peristalsis with a concomitant appearance of pressure waves, and of the other 3, 1 retained anti-peristalsis and the other 2 retained normal peristalsis after surgery; 3) between the reconstructed ureter and the reversely connected ureter, no significant differences were seen in the amplitude, duration, propagation rate, frequency of action potentials and the intraluminal pressure of the ureter.
From these results, together with those previously obtained with the reconstructed ureter, it is suggested: 1) when the muscular conduction of excitation is interrupted physically at some portion of the ureter, peristalsis is caused by the urine flow itself and conducted by muscular propagation to the distal end without any relation to the propagation of excitation from the renal pelvis, and furthermore, 2) the property of ureteral contraction has no influence on the direction of the urine flow.

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The present investigation was undertaken in order to clarify the mechanism of the transport of urine by the pelvi-ureteral system in dogs. Twenty-eight preparations of exteriorized renal pelvis and ureter from 18 dogs were used. Dogs were operated under thiopental anesthesia. The pelvis and ureter were exposed transperitoneally, and electrodes were implanted at the pelvis and ureter. Simultaneous recordings of pelvic and ureteral myograms were obtained.
A vein needle connected to a pressure transducer was placed in the pelvis and pressure within the pelvis was recorded. For mesurement of intraureteral pressure, a No. 18 gauge scalp vein needle was inserted into the ureter below the site of implanted electrode.
These measurements were made simultaneously with myogram recordings. The changes in pelvic and ureteral peristalsis were recorded, together with the corresponding myogram and pressure recordings after rapid diuresis induced by an intravenous infusion of Furosemide (10-20mg). Results:
1) The average frequency of contraction before induced diuresis was 24. 6 times per min. in the pelvis and 8.7 times per min. in the ureter. Namely, the peristaltic frequency of the pelvis before diuresis was greater than that of the ureter by a ratio of 3: 1.
2) During diuresis, the average frequency of contraction was 24.1 times per min. in the pelvis and 22.7 times per min. in the ureter, indicating that the peristaltic activity of the ureter increased as the urine volume increased.
3) The frequency ratio of 1: 1 seen during diuresis remained unchanged for 7 min. and 25 seconds. Subsequently it returned to the pre-infusion level.
4) Pressure within the pelvis showed low and continuous contraction waves corresponding to the amplitudes of pelvic contraction before and after the Furosemide-induced diuresis. In the ureter, however, the high contraction waves corresponding to the amplitude of ureteral contraction were seen. During diuresis, both the standing and contraction pressures within the pelvis and ureter were equally elevated.
The results of the present investigation suggest that the intact pelvis continues a rhythmical contraction, despite the absence of urine, and no peristaltic activity is accelerated in the ureter unless urine in the pelvis passes through the pelvi-ureteral junction to reach the ureter. During marked diuresis, distension of the pelvi-ureteral junction occurs as the intrapelvic pressure increases. Subsequently, the frequency of ureteral peristaltic contractions increases as the ureter at the pelvi-ureteral junction is dilated by urine pressure. At this diuretic stage, the capacity of the ureter to adjust itself to changes in urine volume is limited by its inability to dilate beyond a certain point. Therefore, the increased frequency of ureteral peristaltic contraction expels a larger volume of urine to minimize outflow resistance, thereby reducing back pressure toward the kidney.
The data presented would be prerequisite for the better understanding of the pelvi-ureteral function in man.

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A needle “indwelling” electrode was devised for electro-ureterography through a cystoscope in order to improve the “U-loop” collar electrode reported by Tsuchida and Kimura. Its structure and usability as compared with those of the “U-loop” electrode are reported in this paper.

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For the studies on the recovery of ureters from immotility after operation, 24 dogs were used.
Twelve ureters of 10 dogs were incised 1cm long at the center along the direction of the urinary flow, and 14 dogs had 18 ureters sectioned transversely at the center. Immediately after suturing, the incisions were bound side to side, and the sections were sutured end to end. Their peristaltic movements were recorded by taking the uretero-myograms with 2 sets of the bipolar leads made of platinum wire 0.5mm thick, accoding to Kubo et al. Both were implanted into the wall of the ureter; one 1cm upward and the other 1cm downward, each apart from the operational wound.
Whithin one minute after the operation, all but 2 ureters examined showed some waves of the normoperistalsis found in the part proximal to the wound, and in the distal parts of them no wave of the peristalsis.
A half hour later, 70% of ureters examined showed some movements of peristalsis in the distal part, whereas those of the anti-peristalsis were found 2.5 times more frequently than as those of the normoperistalsis.
The waves of the anti-peristalsis in the distal part were taken for 5 days after the incision and for 14 days after the section. Those action potentials recorded had great difference in the discharge intervals from those in the proximal part.
In the course of the observations, 100% of ureters with the wound sectioned and 75% of those with the incisioned had the urinary fistula formed by the wound.

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In order to investigate the pre-operative and post-operative ureteral function in calculous disease of the upper urinary tract and the direct relationship between its function and urinary fistula-building, various examinations were made by ureteral electromyography through a cystoscope. 47 cases of nephrolithiasis and 53 cases of ureterolithiasis were examined before surgery, then within 2 weeks, after surgery 2-5 weeks and over 5 weeks, and, at the same time, observations were made on how long the urinary fistula remained open without special treatment.
The following results were obtained:
1. The preoperative results; 1) In nephrocalcinosis, the discharge interval of action potentials was found to be prolonged, compared with that of the normal ureter, and antiperistalsis was observed.
But, the amplitude of action potentials, the duration of discharge, and their propagation rate were almost within normal limits.
2) In ureterolithiasis, almost the same results as in nephrolithiasis were obtained.
2. The post operative results; 1) In linear vertical pyelolithotomy, the abnormal action potentials of prolonged discharge interval and antiperistalsis increased within 2 weeks after surgery in all cases. In some cases the action potentials disappeared.
But, the abnormal action potentials showed a tendency to continually decrease and over 5 weeks to decrease even more.
2) In nephrolithotomy, the same tendency as in pyelolithotomy was seen except that the action potentials disappeared.
3) In linear vertical ureterolithotomy, abnormal action potentials of prolonged discharge interval and antiperistalsis increased slightly within 2 weeks in all cases. But after 2-5 weeks they showed a tendency clearly to decrease and over 5 weeks even more clearly.
4) Although there were some exceptions, the general tendency was that the abnormal action potentials slightly increased in cases with urinary fistula-building observed for over 10 days.

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