Diuretic Doppler ultrasonography in chronic unilateral partial ureteric obstruction in dogs.
OBJECTIVE
To compare the effects of diuresis induced by a loop diuretic (frusemide), an osmotic diuretic (mannitol) and a high-osmolar radio-contrast medium (sodium iothalamate) on the intrarenal resistive index (RI) in dogs with chronic unilateral partial ureteric obstruction (UPUO).


METHODS
The split renal clearance and intrarenal RI were estimated in 11 dogs with chronic UPUO. Doppler ultrasonography measurements of the interlobar arteries were obtained before and 10 min after the intravenous infusion of 1 mg/kg frusemide, 1 g/kg mannitol or 20 mL 60% sodium iothalamate. The same experimental protocol was repeated with another drug at 1-week intervals.


RESULTS
There was a significant difference between the intrarenal RI of obstructed and unobstructed kidneys in the chronic phase of UPUO. While mannitol and sodium iothalamate significantly increased the RI in both kidneys, differences in RI between the kidneys decreased after infusing the two drugs. However, while frusemide insignificantly increased the RI in the obstructed kidney, it decreased the RI in unobstructed one. Consequently, the difference in RI between the kidneys increased significantly after administering frusemide. There were no significant differences in urinary volume after administering each of the drugs.


CONCLUSIONS
As there were no significant differences in the diuretic effects of the drugs, frusemide may have additional effects on the RI of unobstructed kidneys other than diuresis. Frusemide increased the difference between the intrarenal RI of the kidneys and therefore may improve the detection of unilateral urinary obstruction in humans.
Yokoyama
H
H
Department of Urology, Fukuoka University School of Medicine, Japan. yokoyama@minf.med.fukuoka-u.ac.jp
Tsuji
Y
Y
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D002908:Chronic Disease; D003287:Contrast Media / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D004234:Diuretics, Osmotic / Q000494:pharmacology; D004285:Dogs; D005260:Female; D005665:Furosemide / Q000494:pharmacology; D007483:Iothalamic Acid / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology; D018608:Ultrasonography, Doppler; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging*; D014655:Vascular Resistance / Q000187:drug effects
D003287:Contrast Media; D004232:Diuretics; D004234:Diuretics, Osmotic; D007483:Iothalamic Acid; D008353:Mannitol; D005665:Furosemide