Antihypertensive effects of the flavonoid quercetin in spontaneously hypertensive rats.
1. The effects of an oral daily dose (10 mg kg(-1)) of the flavonoid quercetin for 5 weeks in spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rats (WKY) were analysed. 2. Quercetin induced a significant reduction in systolic (-18%), diastolic (-23%) and mean (-21%) arterial blood pressure and heart rate (-12%) in SHR but not in WKY rats. 3. The left ventricular weight index and the kidney weight index in vehicle-treated SHR were significantly greater than in control WKY and these parameters were significantly reduced in quercetin-treated SHR in parallel with the reduction in systolic blood pressure. 4. Quercetin had no effect on the vasodilator responses to sodium nitroprusside or to the vasoconstrictor responses to noradrenaline or KCl but enhanced the endothelium-dependent relaxation to acetylcholine (E(max)=58+/-5% vs 78+/-5%, P<0.01) in isolated aortae. 5. The 24 h urinary isoprostane F(2 alpha) excretion and the plasma malonyldialdehyde (MDA) levels in SHR rats were increased as compared to WKY rats. However, in quercetin-treated SHR rats both parameters were similar to those of vehicle-treated WKY. 6. These data demonstrate that quercetin reduces the elevated blood pressure, the cardiac and renal hypertrophy and the functional vascular changes in SHR rats without effect on WKY. These effects were associated with a reduced oxidant status due to the antioxidant properties of the drug.
Duarte
J
J
Department of Pharmacology, School of Pharmacy, University of Granada, 18071 Granada, Spain.
Pérez-Palencia
R
R
Vargas
F
F
Ocete
M A
MA
Pérez-Vizcaino
F
F
Zarzuelo
A
A
Tamargo
J
J
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D015237:Dinoprost / Q000031:analogs & derivatives / Q000652:urine; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology; D006973:Hypertension / Q000188:drug therapy*; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D016877:Oxidants / Q000097:blood / Q000652:urine; D011189:Potassium Chloride / Q000494:pharmacology; D011794:Quercetin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D016877:Oxidants; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D008315:Malondialdehyde; D011189:Potassium Chloride; D011794:Quercetin; D015237:Dinoprost; D000109:Acetylcholine; D009638:Norepinephrine