Vasculotoxic and Proinflammatory Effects of Plasma Heme: Cell Signaling and Cytoprotective Responses

Figure 2

Endogenous CO production in mouse models of SCD. Exhaled CO was collected for 3 hours from C57BL/6, HbAA-, HbAS-, and HbSS-Townes mice (𝑛=5–7 mice/group). C57BL/6 mice injected with phenylhydrazine, an hemolysis inducing drug, 48 and 24 hours before collection of exhaled CO, served as positive controls for breath CO measurements. Exhaled CO was 5.9-fold higher in C57BL/6 mice injected with phenylhydrazine (𝑛=4) than untreated C57BL/6 mice (𝑛=12, ^∗𝑃<0.001). Exhaled CO levels were not significantly higher than untreated C57BL/6 controls in the HbAA- and Hb-AS-Townes (𝑛=4) models. Exhaled CO levels were highest in HbSS-Townes mice (𝑛=4), 6.9-fold higher than HbAA-Townes mice (𝑛=4, ^∗𝑃<0.001). Values are means ± SD.