Effects of losartan on renal function in patients with essential hypertension.
We examined the renal hemodynamic modifications induced by a selective angiotensin II (AII) AT1 receptor antagonist, losartan, in 10 patients with essential hypertension. In this single-blind study, renal hemodynamic parameters were determined twice (patients were their own controls) first after a 15-day single-blind placebo run-in period and again after a 1-month losartan period. The dosage of losartan was 50 mg/day. Glomerular filtration rate (GFR, inulin clearance), renal plasma flow [RPF; para-aminohippurate (PAH) clearance], microalbuminuria, sodium excretion, proximal sodium tubular reabsorption (lithium clearance), and acid uric metabolism were measured. After 1-month losartan treatment, systolic and diastolic BP (SBP, DBP) decreased significantly throughout the 210-min recording whereas heart rate (HR) was unchanged. GFR (100 +/- 19 vs. 96 +/- 17 ml/min/1.73 m2) and RPF (471 +/- 118 vs. 468 +/- 108 ml/ min/1.73 m2) were not altered by losartan. Rather than occurrence of any modification in filtration fraction (FF), a significant decrease in microalbuminuria was evident (57 +/- 77 vs. 40 +/- 59 mg/24 h, p < 0.05). Urinary sodium excretion was not modified, but an almost significant (p = 0.07) decrease in proximal sodium reabsorption was observed (72.9 +/- 7.7 vs. 68.1 +/- 6.4% of filtered sodium). The increase in renal uric clearance accounted for the significant decrease in serum uric acid (195 +/- 49 vs. 183 +/- 43 microM; p < 0.05). After 1-month losartan treatment, renal function was well preserved; the decrease in uric acid may be of clinical interest when adjuvent diuretic therapy is required.
Fauvel
J P
JP
Départment de Néphrologie et d'Hypertension Artérielle, Hôpital Edouard Herriot, CNRS URA 1483, Lyon, France.
Velon
S
S
Berra
N
N
Pozet
N
N
Madonna
O
O
Zech
P
P
Laville
M
M
D000419:Albuminuria / Q000652:urine; D000804:Angiotensin II / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D007093:Imidazoles / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects*; D019808:Losartan; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation / Q000187:drug effects; D016037:Single-Blind Method; D012964:Sodium / Q000097:blood; D013777:Tetrazoles / Q000494:pharmacology*; D014527:Uric Acid / Q000097:blood
D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D007093:Imidazoles; D013777:Tetrazoles; D000804:Angiotensin II; D014527:Uric Acid; D012964:Sodium; D019808:Losartan