Abstract
EMG of the ureter between the pyeloureteral and the ureterovesical junctions of 38 adult dogs was observed under normalcy, and following i. v. injection of 2% xylocaine and 2% novocaine solutions and periureteral injection of 2% xylocaine solution.
The results obtained were as follows:
1. The normal ureteral peristaltic discharges always arise at the pyeloureteral junction and reach the ureterovesical junction, and the propagation velocity of these discharges was higher in the middle part of the ureter than in its upper and lower parts.
2. Following i. v. injection of 4mg./kg. and 10mg./kg. of 2% xylocaine solution, 1) the discharge frequency was definitely increased, 2) the velocity of propagation was accelerated, 3) the intervals between discharges were markedly shortened, groups of discharges of Shiratori et al's14) Group I or II being formed, 4) Type II wave pattern changed into Type I and Type I waves were accompanied by perceptible minor negative deflections and 5) in some cases, feeble waves fading out midways were found emerging in the stage when the frequency after reaching the maximum tended to come down to normal level.
3. Following i. v. injection of 4mg./kg. of 2% novocaine, the frequency increased and the velocity of propagation showed down, but after injection of 10mg./kg. of the same solution, only the frequency rose a little, the propagation velocity, the amplitude, the duration and the wave pattern remaining almost unaffected.
4. The interesting finding that the sensory depressans, xylocaine and novocaine stimulate the ureteral peristaltic movement was obtained.
5. Following injection of xylocaine around the pyeloureteral junction, a series of normoperistaltic discharges was emitted when the site of injection was around the middle part of the ureter, simultaneous antiperistaltic discharges upwards and the normoperistaltic discharges downwards from the site occured serially, and when the injection was administered in the surrounding tissue of the ureterovesical junction, a series of upward antiperistaltic discharges was emitted.
The frequency and the duration time of these serial discharges were the largest in the pyeloureteral junction, next in the ureterovesical junction and the lowest in the middle part of the ureter.
6. It was concluded that the peristaltic movement of the ureter was determined in its direction by the site, normoperistaltic movement alone arising at the pyeloureteral junction, antiperistaltic movement alone at the ureterovesical junction and normo- as well as anti-peristaltic movements at any other middle part of the ureter.
