Early spironolactone treatment attenuates heart failure development by improving myocardial function and reducing fibrosis in spontaneously hypertensive rats

• Grant number: 15/17270-6
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: November 01, 2015
• End date: April 30, 2016
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Katashi Okoshi
• Grantee: Katashi Okoshi
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Background: We evaluated the role of the aldosterone blocker spironolactone in attenuating long-term pressure overload-induced cardiac remodeling and heart failure (HF) in spontaneously hypertensive rats (SHR). Methods and Results: Thirteen month-old male SHR were assigned to control (SHR-C, n=20) or spironolactone (SHR-SPR, 20 mg/kg/day, n=24) groups for six months. Normotensive Wistar-Kyoto rats (WKY, n=15) were used as controls. Systolic blood pressure was higher in SHR groups and unchanged by spironolactone. Right ventricular hypertrophy, which characterizes HF in SHR, was less frequent in SHR-SPR than SHR-C. Echocardiographic parameters did not differ between SHR groups. Myocardial function was improved in SHR-SPR compared to SHR-C [developed tension: WKY 4.85±0.68; SHR-C 5.22±1.64; SHR-SPR 6.80±1.49 g/mm2; -dT/dt: WKY 18.0 (16.0-19.0); SHR-C 20.8 (18.4-25.1); SHR-SPR 28.9 (24.2-34.6) g/mm2/s]. Cardiomyocyte cross-sectional area and total collagen concentration (WKY 1.06±0.34; SHR-C 1.85±0.63; SHR-SPR 1.28±0.39 µg/mg wet tissue) were greater in SHR-C than WKY and SHR-SPR. Type 3 collagen expression was lower in SHR-C than WKY and unchanged by spironolactone. Soluble collagen, type I collagen, and lysyl oxidase did not differ between groups. Conclusion: Early spironolactone treatment decreases heart failure development frequency by improving myocardial systolic and diastolic function and attenuating hypertrophy and fibrosis in spontaneously hypertensive rats. (AU)