Effect of inhalation of nitrous oxide on rabbit ear chamber microvessels.

The purpose of this study is to investigate the effect of inhalation of nitrous oxide (N2O) on peripheral hemodynamics in vivo. We observed changes in the peripheral microcirculation before and during inhalation of 70% N2O -30% O2 for 2 hours, using rabbit ear chamber method in 16 rabbits. In summary, inhalation of N2O causes decrease of the diameters, blood-flow velocities, and blood-flow rates of arterioles; thus participating in the increase of systemic vascular resistance gradually during the first 5 minutes of N2O inhalation. This phenomenon (arteriole vasoconstriction) was maintained for 2 hours.