Renal hemodynamics in essential hypertensives treated with losartan.
ACE-inhibitors are known to have special renal effects, i.e. they increase ERPF, decrease the filtration fraction and lower proteinuria. These effects can be due to a decrease in angiotensin II (AII) levels as well as an increase in bradykinin. New and more specific AII-receptor antagonists may help to distinguish between effects exerted by angiotensin II and those exerted by bradykinin. We investigated the effects of losartan in 9 patients with essential hypertension (sitting mean diastolic blood pressure 95-120 mmHg). Renal hemodynamics were measured by continuous inulin-and PAH-clearance (GFR and RPF) after stopping antihypertensive therapy for 1 week, followed by a 2-week placebo period and after a 4-week treatment phase with losartan (50 mg/die) followed by a therapy with an ACE-inhibitor (ramipril 5mg/die). Additionally, urine albumin excretion (UAE) was measured. Treatment of patients with essential hypertension with losartan resulted in a significant decrease of MAP after three weeks of treatment (121 +/- 8 mmHg under placebo and 114 +/- 10 mmHg under losartan; * = p < 0.05). MAP after four weeks of losartan treatment was 115 +/- 11 mmHg. Regarding changes in renal hemodynamics we could not demonstrate a significant change for neither losartan nor the ACE-inhibitor. Urine albumin excretion was reduced by both treatment regimens in correlation to the magnitude of blood pressure reduction. Our data indicate that losartan induced a significant reduction in MAP in patients with essential arterial hypertension with only moderate effects on renal hemodynamics.
Erley
C M
CM
Section of Nephrology and Hypertension, University of Tübingen, Germany.
Bader
B
B
Scheu
M
M
Wolf
S
S
Braun
N
N
Risler
T
T
D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use; D007093:Imidazoles / Q000627:therapeutic use*; D007668:Kidney / Q000187:drug effects; D019808:Losartan; D008297:Male; D008875:Middle Aged; D017257:Ramipril / Q000627:therapeutic use; D012079:Renal Circulation / Q000187:drug effects*; D012084:Renin-Angiotensin System / Q000187:drug effects; D013777:Tetrazoles / Q000627:therapeutic use*
D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D007093:Imidazoles; D013777:Tetrazoles; D006852:Hydrochlorothiazide; D019808:Losartan; D017257:Ramipril