Mechanisms of Cerebral Arterial Relaxations to Hydrogen Peroxide

摘要: Background and Purpose—The role of hydrogen peroxide in the regulation cerebral arterial tone is not completely understood. Previous studies have demonstrated that causes vasodilation small arteries. The present study was designed to determine mechanisms responsible for relaxations large arteries peroxide. Methods—Rings canine middle without endothelium were suspended isometric force recording modified Krebs-Ringer bicarbonate solution bubbled with 94% O2/6% CO2 (37°C, pH 7.4). Radioimmunoassay technique used levels cAMP cGMP. Results—During contraction UTP (3×10−6 or 10−5 mol/L), (10−6 10−4 mol/L) caused concentration-dependent relaxations. Catalase (1200 U/mL) abolished Inhibition cyclooxygenase by indomethacin (10−5 significantly reduced In contracted KCl (20 mmol/L), the...