Effect of AT(1) angiotensin II receptor antagonists on the sympathetic response to a cold pressor test in healthy volunteers.
The aim of this study was to evaluate the effect of short-term administration of AT(1) angiotensin II receptor antagonists on the sympathetic response to a cold pressor test (CPT) in normotensive healthy volunteers. Eighty-two healthy volunteers were included in this double-blind placebo-controlled study. Blood pressure and heart rate were determined before and 175 minutes after oral administration of placebo, losartan (50 mg), valsartan (80 mg), or eprosartan (600 mg). Immediately, the subjects underwent a CPT and then the same hemodynamic parameters were measured. CPT increased arterial blood pressure (systolic, diastolic, and mean) and heart rate in the placebo-treated group. Pretreatment with a single dose of losartan, valsartan, or eprosartan blunted CPT-induced pressor response but not heart rate increase. Our results demonstrate that endogenous angiotensin II, through stimulation of AT(1) receptor, supports sympathetic-mediated stress response in humans.
Israel
Anita
A
Laboratory of Neuropeptides, School of Pharmacy, Universidad Central de Venezuela, Venezuela. astern88@hotmail.com
Zavala
Lida Esther
LE
Cierco
Maria
M
Gutierrez
Antonio
A
Garrido
Maria del Rosario
Mdel R
D000179:Acrylates / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003080:Cold Temperature; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D019808:Losartan / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D013564:Sympathetic Nervous System / Q000187:drug effects*; D013777:Tetrazoles / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D000068756:Valsartan
D000179:Acrylates; D047228:Angiotensin II Type 1 Receptor Blockers; D007093:Imidazoles; D013777:Tetrazoles; D013876:Thiophenes; C068373:eprosartan; D000068756:Valsartan; D014633:Valine; D019808:Losartan