Flavonoid-induced reduction of ENaC expression in the kidney of Dahl salt-sensitive hypertensive rat.
Flavonoid, a plant extract, exhibits various biological actions. Dietary flavonoid intake is reported to reduce an elevated blood pressure, however the mechanism is unknown. The epithelial Na+ channel (ENaC) in the kidney plays a key role in the regulation of blood pressure by contributing to the Na+ reabsorption in renal tubules. Thus, we investigated the effect of quercetin, a flavonoid, on ENaC mRNA expression in the kidney of hypertensive Dahl salt-sensitive rats. Dahl salt-sensitive rats of 8 weeks were acclimated for 1 week in a metabolic cage and were subsequently kept for 4 weeks under four different conditions: (1) normal salt diet (0.3% NaCl), (2) normal salt diet with quercetin (10 mg/kg/day), (3) high-salt diet (8% NaCl), and (4) high-salt diet with quercetin. Quercetin diminished the alphaENaC mRNA expression in the kidney associated with reduction of the systolic blood pressure elevated by high-salt diet, suggesting that one of the mechanisms of the flavonoid's antihypertensive effect on salt-sensitive hypertension would be mediated through downregulation of ENaC expression in the kidney.
Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
Wataru
W
Aoi
Naomi
N
Niisato
Hiroaki
H
Miyazaki
Yoshinori
Y
Marunaka
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001835:Body Weight; D002712:Chlorides / Q000652:urine; D003106:Colon / Q000033:anatomy & histology / Q000378:metabolism; D006400:Hematocrit; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D011188:Potassium / Q000652:urine; D011794:Quercetin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020303:Rats, Inbred Dahl; D012964:Sodium / Q000652:urine; D015222:Sodium Channels / Q000096:biosynthesis* / Q000187:drug effects; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D014882:Water-Electrolyte Balance / Q000502:physiology
D000959:Antihypertensive Agents; D002712:Chlorides; D012333:RNA, Messenger; D015222:Sodium Channels; D017673:Sodium Chloride, Dietary; D011794:Quercetin; D012964:Sodium; D011188:Potassium