Effects of saline load, Roentgen contrast medium and indomethacin on diuresis and pelvic pressure in the acute obstructed kidney. An experimental study.

In anaesthetised pigs indomethacin (2.5 mg/kg body weight) immediately reduced pelvic pressure above unilaterally and bilaterally totally occluded ureters. Repeated administration of the same dose caused a cumulative reduction of pelvic pressure. In animals with a kidney working against a partial obstruction of the ureter, indomethacin reduced urine production by more than 50% within 15 to 30 min. It was also shown that the effect of indomethacin on the pelvic pressure was dependent on the fluid load of the animals. Rapid infusion of saline or X-ray contrast medium counteracted the pressure fall induced by indomethacin.