Fig. 1.

B-mode Doppler ultrasound in vivo data from the carotid artery of mice under anesthesia (inhaled isoflurane) before, during (at ~4.5 mo), and after 8 mo of chronic exposure to electronic cigarette (E-cig) vapor and reference tobacco (3R4F) cigarette smoke. A: significant increase in arterial stiffness [measured as pulse wave velocity (PWV)] for E-cig and 3R4F groups following 8-mo exposure. B: significantly greater change in PWV (translating to greater arterial stiffness) after 8 mo in E-cig- and 3R4F-exposed than control (air-exposed) mice. Slight, nonsignificant, rise in PWV in control mice following 8 mo is consistent with the normal aging effect. n = 5–8 mice/group. *P < 0.05 vs. air.