β-Adrenergic Blockade in Developing Heart Failure

作者：Sumanth D. Prabhu, Bysani Chandrasekar, David Reginald Piper Murray, Gregory L. Freeman · 发表于：Circulation · 年份：2000 · DOI：10.1161/01.cir.101.17.2103 · 被引用次数：266 · 研究领域：Cardiac Fibrosis and Remodeling、Heart Failure Treatment and Management、Cardiovascular Function and Risk Factors

BACKGROUND: Whether beta-adrenergic blockade modulates myocardial expression of inflammatory cytokines and nitric oxide (NO) in heart failure is unclear. METHODS AND RESULTS: We administered oral metoprolol or no therapy to rats for 12 weeks after large myocardial infarction and subsequently examined left ventricular (LV) remodeling; myocardial tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 expression; and NO. In untreated rats, echocardiography revealed significant (P<0.001) LV dilatation and systolic dysfunction compared with sham. Papillary muscle studies revealed isoproterenol hyporesponsiveness to be unaltered by NO synthase (NOS) inhibition. Circulating NO metabolites were undetectable. In noninfarcted myocardium, although inducible NOS (iNOS) mRNA was absent, TNF-alpha, IL-1beta, and IL-6 mRNA and protein were markedly elevated compared with sham (P<0.001), with 2-fold higher expression (P<0.025) of IL-6 compared with TNF-alpha or IL-1beta. Metoprolol administration starting 48 hours after infarction (1) attenuated (P<0.02) LV dilatation and systolic dysfunction, (2) preserved isoproterenol responsiveness (P<0.025) via NO-independent mechanisms, and (3) reduced myocardial gene expression and protein production of TNF-alpha and IL-1beta (P<0. 025) but not IL-6, which remained high. CONCLUSIONS: During heart failure development, adrenergic activation contributes to increased myocardial expression of TNF-alpha and IL-1beta but not IL-6, and one mechan...