Long Term Pulmonary Effects of E‐cigarettes on in‐utero Exposed Mice

Abstract

IntroductionThe in‐utero environment is delicate, as it fosters the proper health and growth of the fetus. Negative environmental effects during gestation increase the chances of long‐term developmental consequences. As e‐cigarettes gain popularity in pregnant mothers, the aim of this study is to observe the chronic pulmonary function of adult mice exposed to e‐cigarette vapor during gestation.MethodsPregnant mice underwent exposure for 4 hours a day, 5 days a week beginning from the first day of pairing for breeding and ending at birth. Mice were separated into three exposure groups each receiving one 70 mL e‐cig vapor puff per minute of (1) E‐cig vapor with nicotine Nic(+) (2% Nic 50:50 propylene glycol:vegetable glycerin), (2) E‐cig exposure without nicotine Nic(‐) (propylene glycol: vegetable glycerin), or (3) continuous filtered air exposure (FA)HEPA filter. Resulting pups from each group were examined at adulthood (4‐5 months). Data including baseline lung mechanic scan and a dose response to different concentrations of methacholine, a drug used to induce airway hyperreactivity, were obtained via the FlexiVent FX2 (SCIREQ Inc.)ResultsMale and female offspring of mice exposed to Nic(‐) and Nic(+) witnessed a significant decrease in overall lung function as compared to the FA group. Baseline compliance (Crs) was significantly decreased in the Nic(‐) female group and Nic(‐) and Nic(+) male groups (P < 0.05 via ANOVA). Female and male mice in the Nic(‐) had greater stiffness (Ers) than the corresponding FA group (P < 0.05). Upon addition of methacholine, female mice in the Nic(‐) and male mice in the Nic(+) had an increased amount of lung resistance (Rrs)upon inhalation (P < 0.05). Female mice in the Nic(‐) had decreased forced expiratory volume (FEV0.1) in comparison with the FA group (P < 0.05).ConclusionPreliminary data supports that in‐utero exposed mice to e‐cigarette vapor with or without nicotine causes long term alterations in lung function. Future directions aim to understand the mechanisms of change through observing changes in histology, altered gene expression, protein analysis, and epigenetic changes through DNA methylation. Results of this work demonstrate that vaping may not be a safe alternative to smoking during pregnancy as the health of the offspring have detrimental pulmonary effects in adulthood.