Mineralocorticoid receptor antagonist spironolactone improves left ventricular remodeling in patients with congestive heart failure and acute myocardial infarction

Spironolactone alleviates myocardial fibrosis via inhibition of Ets‑1 in mice with experimental autoimmune myocarditis

Spironolactone improves cardiac structure, function and prognosis in patients with heart failure and delays the progression of cardiac fibrosis. However, the exact underlying mechanism of this process remains to be elucidated. The present study therefore aimed to explore the protective effect and underlying mechanism of the aldosterone receptor antagonist, spironolactone, on myocardial fibrosis in mice with experimental autoimmune myocarditis (EAM). The EAM model was induced in BALB/c mice via immunization with murine cardiac α-myosin heavy chain sequence polypeptides. The cardiac function of the mice was assessed using echocardiography and the levels of inflammatory cytokines were quantified using ELISA. E26 transformation-specific sequence-1 (Ets-1) expression was knocked down using lentivirus-mediated small interference RNA. Total collagen deposition was assessed using Masson's trichrome and Ets-1, TGF-β1, Smad2/3, collagen I and III protein expression levels were detected using immunohistochemistry and western blotting. MMP-2 and MMP-9 mRNA expression levels and activity was determined using reverse transcription-quantitative PCR and gelatin zymography, respectively. The results of the present study demonstrated that spironolactone significantly improved myocardium hypertrophy, diastolic cardiac function and decreased myocardial inflammation and collagen deposition induced by EAM. Spironolactone treatment significantly inhibited Ets-1 and smad2/3 phosphorylation. In addition, inhibition of Ets-1 reduced the expression and activity of MMP-2 and MMP-9 and decreased cardiac fibrosis in EAM mice. The results indicated that the improvement of myocardial fibrosis by spironolactone may be associated with the TGF-β1/Smad-2/3/Ets-1 signaling pathway in EAM mice.

[Effects of various diuretics on cardiac function in rats with heart failure]

Torasemide is a long-acting loop diuretic that combines the effects of both furosemide and spironolactone. It has been reported that torasemide but not furosemide might attenuate myocardial remodeling accompanied by left ventricular (LV) dysfunction. However, nothing is known about the effect of torasemide, long-acting loop diuretic and spironolactone, an aldosterone receptor antagonist in a rat model of chronic heart failure (CHF). Therefore, we compared the therapeutic effects of torasemide, furosemide and spironolactone on the progression of LV remodeling in a rat model of CHF after experimental autoimmune myocarditis (EAM). EAM was elicited in Lewis rats by immunization with porcine cardiac myosin. Twenty-eight days after immunization, rats were treated for 28 days with torasemide, furosemide and spironolactone. Diuretic actions, heart weight/body weight, heart rate, mean blood pressure, myocardial function by echocardiography, cardiac fibrosis, myocyte diameter and cardiac aldosterone synthetase (CYP11B2) were evaluated. Increased cardiac CYP11B2, severe LV remodeling and resultant cardiac dysfunction was found in CHF rats, whereas decreased cardiac CYP11B2, less remodeling and improvement of cardiac function were found in torasemide- and spironolactone-treated CHF rats. Our results indicate that torasemide and spironolactone treatment significantly improved cardiac function and LV remodeling compared with furosemide treatment.

Angiotensin-converting enzyme inhibition intervention in elderly persons: effects on body composition and physical performance

The disablement process is often accompanied by sarcopenia or muscle loss, which is associated with virtually all identified disability risk factors. Clinically, the association between body composition and physical performance has been documented by several studies. However, loss of strength is greater than loss of muscle mass with age implying that the quality of remaining muscle may be reduced. Although there are limited data explaining potential physiological mechanisms that contribute to muscle quality, sarcopenia is frequently associated with fat accumulation, and the percentage of body fat increases with age even if weight does not. However, the relationship between fat and muscle function may not be linear, suggesting that there may be an optimal ratio of lean to fat mass for physical function. There are no definitive pharmacological interventions proven to prevent decline in physical function either by modulating body composition or by other means. One exception may be angiotensin-converting enzyme inhibitors (ACEIs). ACE is an important component of the renin-angiotensin system, the central hormonal regulator of blood pressure. Recent evidence suggests that ACEIs may improve physical function by means of direct effects on body composition in older persons, rather than through its blood-pressure-lowering effects. Clinical and genetic studies in humans and experimental evidence in animals suggest that modulation of the renin-angiotensin system is associated with metabolic and biochemical changes in skeletal muscle and fat, changes that are associated with declining physical function. ACEIs may modulate this process through a variety of molecular mechanisms including their influence on oxidative stress and on metabolic and inflammation pathways. This review describes potential biological mechanisms of ACE inhibition and its contribution to declining physical performance and changing body composition. Promising pharmacoepidemiological studies and experimental evidence in animals suggest that there are appropriate models in which to study this effect.