Direct measurement of nitric oxide concentration in isolated vessels and isolated beating hearts by nitric oxide microsensor

There is much value to be obtained from evaluating the real-time change of nitric oxide (NO) in cardiovascular systems, since NO plays roles in various physiological and pathophysiological phenomena, including vasorelaxation and atherosclerosis. The authors thus applied a new NO microsensor (100 μmφ), which allows one to directly measure NO release on a real-time basis with high temporal and spatial resolutions, to the measurement of NO in isolated arteries and hearts where NO plays key roles. The NO concentration (measured current) in canine femoral arterial wall increased linearly with increasing perfusion flow rate. It was also increased by acetylcholine and decreased by N^G-nitro-L-arginine. The NO concentration in the coronary effluent of isolated beating rat hearts also increased with increasing perfusion flow rate and showed transient changes during ischemia-reperfusion