[The study on the function of the intramural portion of the ureter. The motion of the intramural portion of the ureter in dogs].
The present investigation was performed in order to clarify whether the motion of the intramural portion of the ureter is passive or active. In Experiment I, electromyograms of the extravesical and intramural portions of the ureter were recorded using bipolar suspended electrodes and bipolar needle electrodes for 52 ureters in 26 adult mongrel dogs to study the relationship between both portions of the ureters in the nondiuretic and diuretic state. In Experiment II, using 14 ureters in 10 adult mongrel dogs, electromyograms were recorded and the local forces of the ureteral walls of the extravesical and intramural portions were measured with a special needle electrode concurrently.


RESULTS
(1) Experiment I demonstrated in the nondiuretic and diuretic state, 1. no significant differences in the ureteral discharge frequency between the extravesical and intramural portion of the ureters, and 2. a 1:1 correspondence in the extravesical and intramural action potentials. (2) Increases were observed in the local forces of the ureteral walls of the intramural portion of the ureters following action potentials. From these experimental results, it was suggested that the intramural portion of the ureter actively moves due to muscular excitation from the upper ureter and participates in urine transport.
Kumasaka
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K
Department of Urology, School of Medicine, Iwate Medical University.
Kawamura
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S
D000200:Action Potentials; D000818:Animals; D004285:Dogs; D004576:Electromyography; D008365:Manometry; D009068:Movement; D014513:Ureter / Q000502:physiology*; D001743:Urinary Bladder / Q000502:physiology; D014554:Urination