RT Journal Article
SR Electronic
T1 Contribution of Bradykinin B2 Receptors to the Inhibition by Valsartan of Systemic and Renal Effects of Exogenous Angiotensin II in Salt-Repleted Humans
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 911
OP 916
DO 10.1124/jpet.110.166942
VO 334
IS 3
A1 Almerina Biggi
A1 Luisa Musiari
A1 Matteo Iori
A1 Giuseppe De Iaco
A1 Giulia Magnani
A1 Irene Pelloni
A1 Silvana Pinelli
A1 Giovanna M. Pelà
A1 Almerico Novarini
A1 Aderville Cabassi
A1 Alberto Montanari
YR 2010
UL http://jpet.aspetjournals.org/content/334/3/911.abstract
AB To investigate whether bradykinin (BK) participates in the inhibition of renal effects of exogenous angiotensin II (AngII) by AngII type 1 receptor (AT1R) blockade, eight salt-repleted volunteers underwent four p-aminohippurate- and inulin-based renal studies of AngII infusion at increasing rates of 0.625, 1.25, and 2.5 ng·kg·min−1 for 30 min. Studies 1 and 2 were preceded by 3 days of placebo, whereas studies 3 and 4 used 240 to 320 mg·day−1 valsartan. Bradykinin B2-type receptor (BKB2R) antagonist icatibant (50 μg·kg−1) was coinfused in studies 2 and 4. Mean blood pressure (MBP), glomerular filtration rate (GFR), renal blood flow (RBF), and renal sodium excretion (UNaV) were measured. In study 1, MBP rose by 12.8%, UNaV decreased by 68%, and GFR and RBF also fell (p < 0.001 for all). In study 2, GFR and RBF fell as in study 1, but the rise in MBP and the fall in UNaV were accentuated [+20.0%, analysis of variance (ANOVA), p < 0.02 versus study 1 and −80.0%, p < 0.05, respectively]. In study 3, AngII had no effects, and in study 4, renal hemodynamics remained unaffected, but MBP still rose and UNaV fell (ANOVA, p < 0.02 and 0.005 versus study 3, respectively). Icatibant accentuated AngII-induced changes in MBP and UNaV. Previous AT1R blockade prevented any systemic and renal effects of AngII, but significant changes in MBP and UNaV still followed AngII plus icatibant even after AT1R blockade. BK, through BKB2Rs, participates in the inhibitory action of AT1R blockers toward actions of exogenous AngII on MBP and UNaV in healthy humans.