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Early rather than late aldosterone blockade improves myocardial function in spontaneously hypertensive rats without heart failure
Author(s) -
CEZAR MARCELO DIARCADIA MARIANO,
Junior Silvio,
Martinez Paula,
Damatto Ricardo,
Lima Aline,
Bonomo Camila,
Guizoni Daniele,
Campos Dijon,
Moretto Fernanda,
Blotta Daniella,
Rosa Camila,
Campana Alvaro,
Okoshi Marina,
Okoshi Katashi
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1036.7
Subject(s) - aldosterone , medicine , spironolactone , blockade , cardiology , blood pressure , heart failure , cardiac function curve , heart rate , analysis of variance , endocrinology , receptor
The purpose of this study was to compare the effect of early and late aldosterone blockade with spironolactone (SPR) on ventricular remodeling in spontaneously hypertensive rats (SHR) without HF. Methods SHR were divided into four groups: control: CTL13 (n=20) 13 month‐old and CTL16 (n=72) 16 month‐old; SPR: SPR13 (n=24) 13 month‐old and SPR16 (n=34) 16 month‐old. SPR groups were treated with SPR for six months (20 mg/kg/day). Systolic blood pressure (BP) was measured. Echocardiogram (ECHO) was performed to evaluate cardiac structures and left ventricular (LV) function. Myocardial function was analyzed in LV papillary muscle preparations. Statistics: two way ANOVA and Student‐Newman‐Keuls. Significance: p<0.05. Results BP was not different between groups (CTL13: 184±24; SPR13: 197±22; CTL16: 199±43; SPR16: 200±35 mmHg; p>0.05). ECHO did not show differences between groups. In vitro evaluated myocardial function was improved in SPR13 vs. CTL13 group (developed tension (dT): 7.00±1.68 vs. 5.22±1.64 g/mm2; maximum rate of dT: 61.0±17.4 vs. 46.8±5.00 g/mm2/s; maximum rate of tension decline: 28.9±7.06 vs. 21.6±5.40 g/mm2/s; p<0.05). Mortality rate was significantly lower in SPR16 than CTL16 (38% vs. 71%; p<0.05). Conclusion Aldosterone blockade initiated at 13 months but not at 16 months induces beneficial effects on myocardial function and collagen accumulation in SHR without heart failure.