Simultaneous Intravascular Two-Dimensional Plus Doppler Ultrasound Is Useful for Evaluation of Postischemic Vasodilatation: Plasma NOx- Levels Determined by the Griess Method May Not Reflect the Extent of Postischemic NO-Induced Vasodilatation

Our objective was 1) to assess postischemic vasodilatation using simultaneous intravascular two-dimensional and Doppler ultrasound, and 2) to clarify whether plasma nitrite and nitrate (NOx-) levels change during postischemic vasodilatation. The vascular cross-sectional area (GSA) was evaluated in 18 mongrel dogs, and the average instantaneous peak velocity (APV) in the iliac arteries after the 5-min occlusion of blood flow was determined. Plasma NOx- levels were measured at the baseline, during the occlusion of blood flow, and 1.5, 3, and 10min after recanalization. The %CSA significantly increased from 30s to 7 min after the recanalization, and maximal vasodilatation was observed at 1.5min after the recanalization (14.1±0.9 to 15.8±1.0mm2, p