Figure 5.

Increased ROS and Decreased NO Bioactivity in RBCs Contribute to Endothelial Dysfunction in COVID-19

(A) Production of reactive oxygen species (ROS) with electron paramagnetic resonance in H-RBCs (n = 7) and C19-RBCs (n = 10) expressed as percentage of H-RBCs. (B) Endothelium-dependent relaxation induced by ACh in rat aorta following incubation of C19-RBCs in the absence or presence of the superoxide dismutase mimetic TEMPOL (n = 8). (C) Change in nitrate levels with high-performance liquid chromatography in the supernatant following incubation of H-RBCs and C19-RBCs with the arginase inhibitor ABH at concentrations indicated (n = 9-11). ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001 with unpaired Student's t-test (A), 2-way analysis of variance (ANOVA) matched for both concentration and relaxation (B), and 1-way ANOVA with Holm-Sidak’s post hoc test (C). Values are expressed as mean ± SD (A, C) or mean and SD (B). Other abbreviations as in Figures 2 and 4.