Chronic administration of furosemide augments renal weight and
glomerular capillary pressure in normal rats.
Lane, Pascale H., Larry D. Tyler, Paul G. Schmitz, Departments Of
Pediatrics, and Internal Medicine, Cardinal Glennon Children's
Hospital and Saint Louis University Health Sciences Center, St.
Louis, Mo Usa.
Paul G. Schmitz, MD, St. Louis University Health Sciences Center,
Department of Internal Medicine, Division of Nephrology, 3635 Vista
Avenue, St. Louis, Missouri 63110, FAX: 314-771-0784, Phone: 314-577
-8765, E-mail: schmitzm@slu.edu
APStracts 5:0090F, 1998.
Angiotensin II (ANG II) is believed to promote progressive renal
injury via augmented glomerular capillary hydraulic pressure (PGC).
Acute volume reduction secondary to diuretic administration increases
circulating ANG II and augments PGC, yet the hemodynamic effects of
sustained diuretic administration are unknown. Therefore, glomerular
micropuncture studies were performed in male Munich-Wistar rats after
6-8 weeks of treatment with daily furosemide (F; 40 mg/d), furosemide
plus the AT1 receptor antagonist, losartan (F+L; 5 mg/d), or no
therapy (C; control). Renal weight was increased in F rats (1.23 +/-
0.7 gm) versus C (1.00 +/- 0.06 gm) or F+L (0.97 +/- 0.01 gm). In
addition PGC was elevated in F animals (52.1 +/- 1.5 mm Hg) versus C
(43.7 +/- 1.5) or F+L treated rats (41.3 +/- 1.7). F treated rats
were also characterized by a relative increase in efferent arteriolar
resistance and filtration fraction. The latter was markedly
attenuated in F+L treated animals. Collectively, these findings are
consistent with an ANG II-mediated alteration in intrarenal
hemodynamics. In contrast to acute volume manipulations, however,
chronic furosemide augmented renal growth while losartan
administration completely arrested this phenomenon. Further studies
are warranted to determine if the hemodynamic and growth adaptations
elicited by chronic F administration induce or accelerate renal
injury.
Received 24 July 1997; accepted in final form 27 April 1998.
APS Manuscript Number F247-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 8 May 1998