Effects of NO inhalation on NO metabolite levels and sRBC adhesion in eNOS-deficient mice. (A) Plasma nitrate/nitrite levels in eNOS-deficient mice that inhaled NO gas under normoxia or hypoxia. Plasma nitrate/nitrite levels were determined using the Nitrate/Nitrite Colorimetric Assay Kit (Cayman Chemical). Values were mean ± SEM from 3 to 4 mice in each group. P values are shown in the figure. (B) Modulation by NO inhalation of sRBC adhesion in postcapillary venules of eNOS-deficient mice. eNOS-deficient mice were treated with 4 or 20 ppm NO gas at normoxia (procedure III) or hypoxia (procedure IV). Values were mean ± SEM from 5 to 7 mice in each group. P values are shown in the figure. (C) Frame-captured images from videotaped intravital microscopy of bone marrow postcapillary venules in eNOS-deficient mice after injection of BCECF-labeled sRBCs under normoxia, hypoxia, and hypoxia with 20 ppm NO. Arrows indicate adhered sRBCs.