Dihydromyricetin improves vascular hyporesponsiveness in experimental sepsis via attenuating the over-excited MaxiK and KATP channels

AbstractContext: Dihydromyricetin (DMY) has oxidation resistance, anti-inflammatory and free radical scavenging capabilities. The preventive effects of DMY for vascular hyporeactivity remain unclear.Objective: This study investigates the preventive effects of DMY in vascular hyporeactivity.Materials and methods: The experimental sepsis was induced by transvenous administration of lipopolysaccharide (LPS) to Sprague–Dawley (SD) rats. DMY-treated rats received daily administration of DMY, 5 μg/kg dissolved in DMSO through the tail vein for 7 days. The invasive mean arterial pressure (MAP) of the caudal ventral artery was measured. Dose-response curves for norepinephrine (NE, doses from 10−9 to 10−6 M) were obtained in isolated thoracic aorta in a cumulative manner. The function of MaxiK and KATP channels were investigated using whole-cell patch clamp recording. The Elisa was adopted to measure the serum concentration of NO, MDA, 3-NT, IL-1β and TNF-α.Results: The increased MAP in septic rats induced by vaso...