Fourteen-day E-Cigarette Exposure Disrupts Ventilation Patterns and Serum IL-1B Levels in Adolescent Rats

Abstract

E-cigarettes are devices used to deliver vaporized liquids often containing nicotine and other chemicals. The purpose of this study was to investigate the effects of 14 days of e-cigarette vapor exposure in adolescent rats on lung function and inflammatory cytokine expression. Seventeen male long-evans rats were assigned to vape or air groups. The animals were exposed to either air or 5% nicotine vapor using a whole-body exposure chamber, once a day for ten minutes for fourteen consecutive days. Ventilation recordings were completed on day 0 (before exposure) and day 15 (after exposure) using unrestrained whole-body plethysmography. Both lung tissue and blood was collected for molecular assays. Baseline and post-exposure ventilation data were compared between air and vape groups across three different parameters: frequency, tidal volume, and minute ventilation. These parameters were compared resulting in three distinct 2x2 (time x treatment) Mixed Model ANOVAs. Between baseline and post-treatment measurements there was a significant decrease in values in minute ventilation (p=0.0312) and tidal volume (p=0.0031). Between treatment groups there was a significant difference in minute ventilation (p=0.0128) and frequency (p=0042). There were also significant alterations to the presence of IL-1B in the serum (p=0.0003), but not lung tissue (p=0.6525). In conclusion, following two weeks of e-cigarette vapor exposure, ventilation patterns were altered in the vapor exposed animals which decreased in tidal volume and minute ventilation suggesting possible impairment of lung function and e-cigarette exposure modified the expression of pro-inflammatory cytokine, IL-1B.