The studies reported here were undertaken to relate ureteral blood flow to ureteral peristalsis activity during diuresis. Twenty-eight dogs weighing 13 to 23kg were anesthetized with Thiopental and the ureter was exteriorized transperitoneally. Ureteral peristalsis was continuously recorded by electromyography and intraureteral pressure measurement. Diuresis was induced by an intravenous administration of Furosemide (1mg/kg). Urine was collected every 5min. through a catheter (2mm in outer diameter: 1mm in inner diameter) placed in the lower ureter, and the ureteral stroke volume was estimated.
Ureteral intramural PO
2, an index of ureteral blood flow, was continuously measured by using Yagi's polarographic oxygen electrode of an enameled copper wire 300μ in diameter implanted in the ureteral intramural tissues. Changes in the polarographic amplitudes during diuresis were expressed as 100 of the prediuretic level.
The results obtained were as follows:
1. The mean increment of the ureteral intramural PO
2 during 100% oxygen breathing was 197 (115-660). Thus, the Yagi's polarographic PO
2 measurement was proved to be a useful tool for monitoring ureteral intramural PO
2 in situ.
2. The increase in ureteral intramural PO
2 during oxygen breathing was accompanied by no change in ureteral peristalsis activity.
3. Three type of ureteral response to diuresis were observed:
1) Type I, frequent and persistent peristalsis, 2) Type II, frequent, but short-lived peristalsis, and 3) Type III, no remarkable change in peristalsis.
Regardless of the types of response the ureteral stroke volume was increased. The ureteral stroke volume was lowest in the first type and largest in the second type.
These results suggest that an increase in the urine transport is due to either an increase in the frequency of peristalsis or an increased urine volume per peristalsis, or both.
4. The first, the second and the third type of ureteric response had the mean ureteral intramural PO
2 values of 110±4, 91±8, and 98±4, respectively, which represent no important difference. And also they do not differ significantly from the prediuretic value.
These findings suggeset the ureteral intramural microcirculation remained unchanged during the ureteral peristalsis activity.
View full abstract