title: Elevated cardiac tissue level of aldosterone and mineralocorticoid receptor in diastolic heart failure: Beneficial effects of mineralocorticoid receptor blocker.
abstract: Cardiac aldosterone levels have not been evaluated in diastolic heart failure (DHF), and its roles in this type of heart failure remain unclear. This study aimed to detect cardiac aldosterone by use of a liquid chromatographic-mass spectrometric method and to assess the effects of mineralocorticoid receptor blockade on hypertensive DHF. Dahl salt-sensitive rats fed 8% NaCl diet from 7 wk (hypertensive DHF model) were divided at 13 wk into three groups: those treated with subdepressor doses of eplerenone (12.5 or 40 mg x kg(-1) x day(-1)) and an untreated group. Dahl salt-sensitive rats fed 0.3% NaCl diet served as controls. Cardiac aldosterone was detected in the DHF rats but not in the control rats, with increased ventricular levels of mineralocorticoid receptor. Cardiac levels of 11-deoxycorticosterone, corticosterone, and 11-dehydrocorticosterone were not different between the control and DHF rats, but the tissue level of corticosterone that has an affinity to mineralocorticoid receptor was 1,000 times as high as that of aldosterone. Aldosterone synthase activity and CYP11B2 mRNA were undetectable in the ventricular tissue of the DHF rats. Administration of eplerenone attenuated ventricular hypertrophy, ventricular fibrosis, myocardial stiffening, and relaxation abnormality, leading to the prevention of overt DHF. In summary, the myocardial aldosterone level increased in the DHF rats. However, its value was extremely low compared with corticosterone, and no evidence for enhancement of intrinsic myocardial aldosterone production was found. The upregulation of mineralocorticoid receptor may play a central role in the pathogenesis of DHF, and blockade of mineralocorticoid receptor is likely an effective therapeutic regimen of DHF.
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Ohtani
authors.forename: Miho
authors.initials: M
authors.lastname: Ohta
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Mano
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sakata
authors.forename: Mayu
authors.initials: M
authors.lastname: Nishio
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Takeda
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miwa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Okamoto
authors.forename: Tohru
authors.initials: T
authors.lastname: Masuyama
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Nonaka
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hori
mesh_terms: D000450:Aldosterone / Q000378:metabolism*; D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D019405:Cytochrome P-450 CYP11B2 / Q000096:biosynthesis; D003971:Diastole / Q000502:physiology; D000077545:Eplerenone; D006333:Heart Failure / Q000188:drug therapy* / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D000451:Mineralocorticoid Receptor Antagonists; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D020303:Rats, Inbred Dahl; D018161:Receptors, Mineralocorticoid / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013148:Spironolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D013256:Steroids / Q000378:metabolism; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D000451:Mineralocorticoid Receptor Antagonists; D012333:RNA, Messenger; D018161:Receptors, Mineralocorticoid; D013256:Steroids; D000804:Angiotensin II; D013148:Spironolactone; D000450:Aldosterone; D000077545:Eplerenone; D019405:Cytochrome P-450 CYP11B2