Abstract 136: Vascular Impairment From Acute Exposure To E-cigarette Aerosol Is Rescued By Inhibition Of The Receptor For Advanced Glycation End Products (RAGE)

Introduction: E-cigarette use is known to induce vascular impairment by altering vasomotor and cellular functions of the vascular wall, but the molecular mechanism of e-cigarette-induced vascular impairment is largely unexplored. We investigated whether inhibition of RAGE prevents impairment of vasomotor function from acute e-cigarette exposure Hypothesis: Impairment of endothelial vasodilatory function requires the activation of RAGE. Methods: Anesthetized rats (n=8/group) were exposed to aerosols from flavorless tank style e-cigarettes with and without freebase nicotine (12 mg/ml) or air in a single session of 10 cycles of pulsatile 5s exposure over 5 minutes. For each exposure condition, groups received either 1 mg/kg of RAGE inhibitor FPS-ZM1 or vehicle i.p. 1 hour before exposure (i.e., total of 6 groups). Femoral artery flow-mediated dilation (FMD) was measured using micro-ultrasound before and after exposure. Results: Exposure to e-cigarette aerosol with and without nicotine impaired FMD in vehicle groups (8.3±2.7% pre-exposure vs 4.7±2.4% post-exposure, p=0.01; 9.3±4.6% pre- vs 4.8±2.7% post-, p=0.03, respectively), with no change in air control (9.7±3.2% pre- vs 9.3±3.5% post-, p=0.81). Post-exposure FMD in both aerosol groups with vehicle was lower than that in the air group with vehicle (p=0.01 for each aerosol vs air). However, FPS-ZM1 prevented the FMD impairment by aerosol exposure (with nicotine 9.1±3.5% pre- vs 8.9±2.1% post-, p=0.90; without nicotine 9.5±4.3% pre- vs 7.1±2.0% post-, p=0.17), with no change in air control (7.6±2.7% pre- vs 7.4±3.1% post-, p=0.86). Post-exposure FMD values in both aerosol groups receiving FPS-ZM1 were comparable to the air control (p=0.4 and 0.8, respectively). There were no significant difference in post-exposure FMD in the air groups receiving FPS-ZM1 or vehicle (p>0.99). Conclusions: RAGE mediates e-cigarette-induced acute impairment of endothelial vasodilatory function.