Comparison of vasopeptidase inhibitor omapatrilat and angiotensin receptor blocker candesartan on extracellular matrix, myeloperoxidase, cytokines, and ventricular remodeling during healing after reperfused myocardial infarction.

We determined effects of the vasopeptidase inhibitor (VPI) omapatrilat and angiotensin II type 1 receptor (AT1R) blocker (ARB) candesartan in rats during healing between day-2 and day-21 after reperfused myocardial infarction (RMI) on left ventricular (LV) remodeling and function, and regional matrix metalloproteinase (MMP)-9, tissue inhibitor of MMP (TIMP)-3, inducible-nitric-oxide-synthase (iNOS), oxidant-generating myeloperoxidase (MPO), and cytokines tumor-necrosis-factor (TNF)-α, interleukin (IL)-6 and IL-10, and transforming-growth-factor (TGF)-β1, and collagens. Compared to RMI-placebo, both agents reversed adverse LV remodeling and systolic and diastolic dysfunction, improved collagen remodeling, and normalized MMP-9 (activity, protein, and mRNA), TIMP-3 (protein and mRNA), and iNOS, MPO, TNF-α, IL-6, and TGF-β1 proteins, and improved MMP-9/TIMP-3 balance and IL-10 levels in previously ischemic zones. The results suggest that modulation of matrix proteases, oxidants, cytokines, and NOSs with omapatrilat and candesartan contribute to reversal of adverse collagen and LV remodeling and attenuation of LV dysfunction during healing after RMI.