Electronic nicotine delivery systems or e-cigarettes are devices used to deliver aerosolized liquids often containing nicotine and other chemicals. These devices were originally created as a way to assist with smoking cessation in adults; however, use of these devices is increasing in adolescent and young adult populations. The long and short term effects of vaping are still under active investigation. PURPOSE: The purpose of this study was to investigate the effects of 7 days of e-cigarette vapor exposure in adult rats on lung function and lung tissue inflammatory cytokine expression, specifically IL-1. METHODS: Using random assignment, 10 adult male long-evans rats were assigned to vape (experimental) or air (control) groups. The animals were exposed to either air (n = 4) or 5% nicotine vapor (n=6) using a whole-body exposure chamber, twice a day for ten minutes for seven consecutive days. Ventilation recordings were completed on day 0 (before exposure) and day 8 (after exposure) using unrestrained whole-body plethysmography. Minute ventilation, tidal volume, and breathing frequency were assessed. Blood was collected on day 8 to look for the presence of cotinine (a nicotine metabolite). Whole lung tissue was also collected on day 8 for inflammatory cytokine assay, IL-1 ELISA. RESULTS: Cotinine was found to be present in the serum samples of the vape groups (86.6 ng/ml +/- 1.0 ng/mL) but not the air groups (0.0 ng/mL) confirming drug exposure. Baseline ventilation data collected on day 0 and post-exposure ventilation data collected on day 8 were compared between air and vape groups across three different parameters: minute ventilation, frequency, and tidal volume. These parameters were compared resulting in three distinct two-way ANOVAs comparing the variables time and treatment. No significant difference was found among any of the comparisons (p \u3e 0.05 for all). Similarly, no difference in lung inflammatory cytokine IL-1 was observed in the lung tissue of the air (85.6 pg/mL +/- 10.2 pg/mL) or vape (82.7 pg/mL +/- 14.9 pg/mL) exposure groups (p \u3e 0.05, t-test). CONCLUSIONS: In this study, 7 days of e-cigarette vapor exposure did not affect ventilation parameters or increase the presence of inflammatory cytokine, IL-1, in whole lung tissue. Limitations to this study include a small sample size (n = 10) and unreliable negative-pressure which were used to produce the vapor for the e-cigarette exposure. Future studies will modify the vape exposure system and include a larger sample size
