Fig. 1.

Mouse red blood cells (RBC) contain an active eNOS. In wild type (WT) versus eNOS^−/− mice: (A) mean arterial pressure (MAP), systolic BP and diastolic BP (WT: n=5, KO: n=4), (B) whole blood (WB) nitrite (n=5 per group), and (C) plasma nitrite (n=5 per group). (D) Laser scanning microscopic images representative of n=5 independent experiments showing positive staining for eNOS protein (green) in Ter-119^pos (red) RBCs freshly isolated from WT (left panel) and Harvard eNOS^−/− (center panel) mice. Absence of nuclei in RBCs is shown by negative DAPI (blue) staining. IgG control showing negligible background staining. (E) eNOS expression in RBCs from WT and Düsseldorf eNOS^−/− mice was assessed by immunoprecipitation and western blot analysis and compared to eNOS expression in aortic tissue (data from 2 of 6 independent gels are represented). (F) Densitometric assessment of eNOS expression in mouse RBCs as compared to aorta (n=3). (G) Conversion of ¹⁴C-Arginine to ¹⁴C-Citrulline as a measurement of NOS activity in RBCs from WT and Harvard eNOS^−/− mice (n=4 per group). Data are expressed as mean ± SEM. * denotes p<0.05