Evaluation of nitric oxide bioavailability in coronary vessels of the beating heart

摘要

Coronary endothelium plays a central role in vasomotion control and antithrombotic mechanisms.Since endothelial dysfunction has been reported to be associated with increased cardiovascular risk,several indirect techniques have been employed to evaluate coronary endothelial function or NO bioavailability.However,a growing body of evidences suggests limitations of the indirect methods for evaluation of NO bioavailability.Thus,measuring plasma NO concentration in the coronary circulation will contribute to the evaluation of coronary endothelial function.Since coronary vessels are subjected to the phasic mechanical stresses produced by the cardiac contraction and relaxation and pulsative shear stress to the endothelium plays significant roles in NO bioavailability,we developed a catheter-type NO sensor applicable to the coronary sinus of the beating heart.We could evaluate the NO concentration in basal condition and stimulated condition by acetylcholine.Bioavailability of NO was diminished in an animal model of oxidative stress.Thus,direct measurement of plasma NO concentration by the catheter-type NO sensor is useful to evaluate endothelial function and NO bioavailability in the coronary circulation.