Renal and hemodynamic effects of losartan in conscious dogs during
controlled mechanical ventilation.
Krebs, Martin O., Thorsten Kr[diaeresis]ohn, Willehad Boemke, Rainer
Mohnhaupt, and Gabriele Kaczmarczyk.
Experimentelle Anasthesie, Klinik fur Anasthesiologie and Operative
Intensivmedizin, Medizinische Fakultat Charite der Humboldt
Universitat zu Berlin, Campus Virchow-Klinikum, Augustenburger Platz
1, D-12242 Berlin, Germany
APStracts 5:0203F, 1998.
In 12 conscious dogs we investigated whether the angiotensin II
receptor antagonist Losartan increases renal sodium excretion and
urine volume during controlled mechanical ventilation (CMV) with
positive end-expiratory pressure (PEEP). In four experimental
protocols the dogs were extracellular volume (ECV) expanded (iv
electrolyte solution, 0.5 ml( kg-1 ( min -1) or not, and got Losartan
(100 (g(kg-1(min-1 iv) or not. They breathed spontaneously during the
first and fourth hour and got CMV with PEEP (mean airway pressure 20
cm H2O) during the second and third hour.- Expansion: Dogs with
Losartan excreted about 18% more sodium (69(7 vs 38(5 (mol ( min-1(
kg-1) and 15% more urine during the two hours of CMV due to a higher
glomerular filtration rate (GFR) (5.3(0.3 vs 4.5(0.2 ml ( min-1 ( kg
-1) and tubular effects of Losartan. Without expansion: Sodium
excretion (2.0(0.6 vs 2.6(1.0 (mol ( min-1( kg-1) and GFR (3.8(0.3 vs
3.8(0.4 ml ( min -1 ( kg-1) did not change, urine volume decreased
similarly in both groups during CMV. Plasma vasopressin and
aldosterone increased in both groups, PRA increased from 4.9(0.7 to
7.8(1.3 ng Ang I ( ml -1 ( h -1 during CMV in non-expanded dogs
without Losartan. Mean arterial pressure decreased by 10 mmHg in non
-expanded dogs with Losartan. - In conclusion, Losartan increases
sodium excretion and urine volume during CMV if the ECV is expanded.
If the ECV is not expanded, MAP decrease and/or aldosterone and
vasopressin increase during CMV attenuate the renal effects of
Losartan.
Received 9 July 1998; accepted in final form 5 November 1998.
APS Manuscript Number F163-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 20 November 1998