Selective vasodilator and chronotropic actions of 3′,4′- dihydroxyflavonol in conscious sheep

Abstract

Flavonoids are known to relax isolated large arteries, but the cardiovascular actions of flavonoids are not well studied in vivo. Hence, we determined the systemic and regional haemodynamic responses to a novel synthetic flavonol, 3′,4′-dihydroxyflavonol (DiOHF), in conscious sheep previously instrumented with flow probes on the aorta and coronary, mesenteric, renal, and iliac arteries. Intravenous injection of DiOHF (1.0 mg/kg) caused a delayed but prolonged vasodilatation in the coronary and renal vascular beds, with no changes in the mesenteric or iliac vascular beds. DiOHF induced prolonged increases in heart rate and cardiac output without altering arterial pressure. Pretreatment with N..