[Effect of furosemide on the obstructed kidney]

The effect of furosemide on the obstructed kidney was studied in dogs. In control kidneys (n = 4) the renal blood flow (RBF) was increased transiently after intravenous infusion of 20 mg of furosemide; from 12.9 +/- 1.2 to 14.8 +/- 1.4 ml/min/kg.B.W. No change in the renal pelvic pressure was observed. Urine flow increased from 0.47 +/- 0.12 to 4.98 +/- 1.15 ml/min at 20 minutes after furosemide administration. Increases in the fractional fluid excretion rate (V/GFR), the fractional sodium excretion rate (FENa) and the fractional potassium excretion rate (FEK) were observed and the maximum values were obtained at 20 minutes after furosemide administration. In two-week unilateral incompletely obstructed kidneys (incomplete UUO; n = 5), RBF was lower than that of the control kidney, whereas a tendency of transient increase was also noticed after furosemide administration; from 8.4 +/- 1.9 to 10.5 +/- 2.3 ml/min/kg.B.W. The renal pelvic pressure increased immediately and transiently after furosemide infusion. Increase in the urine flow was significant, but the value was lower than that of control, and the maximum value was marked at 20 minutes after furosemide administration. V/GFR, FENa and FEK were also increased in incomplete UUO, but the peak values were lower than those of control. In two-week unilateral completely obstructed kidneys (complete UUO; n = 5), RBF was markedly decreased (3.14 +/- 0.38 ml/min/kg.B.W.), and no significant increase was noticed after furosemide administration. The renal pelvic pressure was gradually and continuously increased after furosemide infusion. The fractional excretion rate of pelvic urine components was variable. In particular, V/GFR was significantly increased 60 minutes after furosemide administration.(ABSTRACT TRUNCATED AT 250 WORDS)