Central infusion of a nitric oxide donor restores baroreflex control of heart rate in heart failure

Abstract

One of the hallmarks of heart failure (HF) is increased sympathetic nerve activity (SNA) to the heart and the kidney as well as depressed baroreflex control of heart rate (HR), but the mechanisms responsible remain unclear. We hypothesized that HF is associated with a reduction in central levels of NO synthase and that restoration of central NO levels in HF animals would be beneficial. Arterial pressure, HR, cardiac and renal SNA were recorded simultaneously in conscious sheep, at least 4 days after surgery in normal (n=7) and HF animals (n=7). HF was associated with a significant decrease in the levels of NO synthase in the brainstem (n=3). HF sheep had significant increases in baseline car..