Effects of spironolactone in spontaneously hypertensive adult rats subjected to high salt intake
Clinics
; Clinics;66(3): 477-482, 2011. ilus, tab
Article
in En
| LILACS
| ID: lil-585961
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BR1.1
ABSTRACT
OBJECTIVE:
To evaluate the effect of spironolactone on ventricular stiffness in spontaneously hypertensive adult rats subjected to high salt intake.INTRODUCTION:
High salt intake leads to cardiac hypertrophy, collagen accumulation and diastolic dysfunction. These effects are partially mediated by cardiac activation of the renin-angiotensin-aldosterone system.METHODS:
Male spontaneously hypertensive rats (SHRs, 32 weeks) received drinking water (SHR), a 1 percent NaCl solution (SHR-Salt), or a 1 percent NaCl solution with a daily subcutaneous injection of spironolactone (80 mg.kg-1) (SHRSalt- S). Age-matched normotensive Wistar rats were used as a control. Eight weeks later, the animals were anesthetized and catheterized to evaluate left ventricular and arterial blood pressure. After cardiac arrest, a doublelumen catheter was inserted into the left ventricle through the aorta to obtain in situ left ventricular pressurevolume curves.RESULTS:
The blood pressures of all the SHR groups were similar to each other but were different from the normotensive controls (Wistar = 109±2; SHR = 118±2; SHR-Salt = 117±2; SHR-Salt-S = 116±2 mmHg; P<0.05). The cardiac hypertrophy observed in the SHR was enhanced by salt overload and abated by spironolactone (Wistar = 2.90±0.06; SHR = 3.44±0.07; SHR-Salt = 3.68±0.07; SHR-Salt-S = 3.46±0.05 mg/g; P<0.05). Myocardial relaxation, as evaluated by left ventricular dP/dt, was impaired by salt overload and improved by spironolactone (Wistar = -3698±92; SHR = -3729±125; SHR-Salt = -3342±80; SHR-Salt-S = -3647±104 mmHg/s; P<0.05). Ventricular stiffness was not altered by salt overload, but spironolactone treatment reduced the ventricular stiffness to levels observed in the normotensive controls (Wistar = 1.40±0.04; SHR = 1.60±0.05; SHR-Salt = 1.67±0.12; SHR-Salt- S = 1.45±0.03 mmHg/ml; P<0.05).CONCLUSION:
Spironolactone reduces left ventricular hypertrophy secondary to high salt intake and ventricular stiffness in adult SHRs.Key words
Full text:
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Index:
LILACS
Main subject:
Spironolactone
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Hypertrophy, Left Ventricular
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Sodium Chloride, Dietary
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Mineralocorticoid Receptor Antagonists
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Hypertension
Type of study:
Etiology_studies
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Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Clinics
Journal subject:
MEDICINA
Year:
2011
Type:
Article
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Project document