Moderate exercise training improves energetic metabolism, tissue perfusion and induces cardiac and skeletal muscle remodeling. Sildenafil, a potent phosphodiesterase-5 inhibitor used to treat erectile dysfunction, reduces infarct size and increases tissue oxygenation in experimental models of cardiovascular disease. We have evaluated the effects of prolonged moderate exercise training and a repeat administration of sildenafil on the rat gastrocnemius and cardiac muscles. Animals were divided into two groups: sedentary and trained. Each group was subdivided into animals treated with vehicle or with two doses of sildenafil (10 or 15 mg/kg/day) during the last week of training. Physical exercise did not induce cardiac hypertrophy, whereas it increased mRNA levels of the PGC-1α, HIF-1α and VEGF genes, which are involved in mitochondrial biogenesis and angiogenesis, and reduced mRNA levels of FoxO3a, MuRF-1 and Atrogin-1. Sildenafil dose-dependently promoted both angiogenesis, as shown by increased capillary density, and muscle atrophy, as shown by muscle fibre size. These effects were more pronounced in trained animals. Our data confirm the beneficial effects of a moderate and prolonged training on cardiovascular and skeletal systems and document the positive and negative effects of sildenafil on these tissues at doses higher than those used in clinical practice. This report may impact on the use of sildenafil as a substance able to influence sports performance.

No abstract

MSCs play an immunomodulatory paracrine role when injected in rats submitted to carotid arteriotomy, accompanied by the release of VEGF, possibly contributing to the accelerated repair of the injured vascular wall.

Treatment of ZDF rats for 3 weeks with telmisartan, a dual angiotensin II receptor antagonist and partial PPAR-γ receptor agonist, resulted in a significant reduction of myocardial damage induced by I/R and was associated with increased adiponectin and a decrease in inflammatory markers.

BACKGROUND AND PURPOSEThe ability of a chronic treatment with indacaterol, a new ultra-long-acting β2-adrenoceptor agonist, to reverse cardiac remodelling and its effects in combination with metoprolol, a selective β1-adrenoceptor antagonist, were investigated on myocardial infarction in a rat model of heart failure (HF). EXPERIMENTAL APPROACHWe investigated the effects of indacaterol and metoprolol, administered alone or in combination, on myocardial histology, β-adrenoceptor-mediated pathways, markers of remodelling and haemodynamic parameters in a rat model of HF. Five groups of rats were assessed: sham-operated rats; HF rats; HF + indacaterol 0.3 mg·kg ; HF + metoprolol + indacaterol. All pharmacological treatments continued for 15 weeks. KEY RESULTSTreatment with either indacaterol or metoprolol significantly reduced the infarct size in HF rats. However, the combination of indacaterol and metoprolol reduced the infarct size even further, reduced both BP and heart rate, reversed the decrease in ejection fraction, normalized left ventricular systolic and diastolic internal diameters, normalized the decreased β1 adrenoceptor mRNA expression as well as cardiac cAMP levels and reduced cardiac GPCR kinase 2 expression, compared with the untreated HF group. CONCLUSION AND IMPLICATIONSThe results of our study demonstrated an additive interaction between indacaterol and metoprolol in normalizing and reversing cardiac remodelling in our experimental model of HF. The translation of these findings to clinical practice might be of interest, as this combination of drugs could be safer and more effective in patients suffering from HF and COPD. AbbreviationsANP, atrial natriuretic peptide; BNP, brain natriuretic peptide; EF, ejection fraction (%); GRK2, GPCR kinase 2; HF, heart failure; LV, left ventricular; LVIDd, LV diastolic internal diameter; LVIDs, LV systolic internal diameter