Figure 4.

Superoxide radical generation in aorta. Aortic sections from mice exposed to 16 and 60 wk of either air or electronic cigarette (e-cig) vape generated from e-cig liquid containing nicotine (NIC) 0 mg/mL (ECV-0), 6 mg/mL (ECV-6), or 24 mg/mL (ECV-24) were studied. A: incubated with the superoxide probe dihydroethidium (DHE; red) and the nuclear fluorescent stain diamidino-2-phenylindole (DAPI; blue), with or without the superoxide dismutase mimetic Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (+SODm), and imaged with confocal fluoroscopy. B: quantitation of the red fluorescence in A, showing that ECV exposure induced superoxide generation that was quenched by the SODm. Thus, ECV exposure results in vascular superoxide production in an exposure time- and a NIC-dependent manner. Data represent means ± SE of aortic sections from 6 mice. Analysis was done using two-way ANOVA followed by Bonferroni multiple-comparisons test. The differences were considered statistically significant at P ≤ 0.05. *Significant from air-exposed controls at P < 0.05; #significant from ECV-0 at P < 0.05; @significant from ECV-6 at P < 0.05; $significant from the same exposure at 16 wk at P < 0.05; †significant from ECV-24 in the absence of the SODm at P < 0.05. ROS, reactive oxygen species.