Table 2.
Animal models of e-cigarette pulmonary toxicity
| Study | Animal Model | Exposure Method | Exposure Duration | E-Liquid | Device | Key Findings |
|---|---|---|---|---|---|---|
| Lerner et al. (77) | Mouse | Whole body | 3 days, 5 h daily | Nicotine: 16 mg/ml + flavoring | Blu e-cig with Teague TE-10 | CS equivalent serum cotinine levels; increased inflammatory cytokine levels in BAL; oxidative stress in lungs |
| Schweitzer et al. (110) | Mouse | Whole Body | Not stated | Not stated | Nebulized e-liquid | Increased markers of oxidative stress in BAL fluid and plasma 24 h after a single exposure |
| Sussan et al. (121) | Mouse | Whole body | 2 wk, 3 h daily | Nicotine: 18 mg/ml + flavoring | NJOY rechargeable | Increased lipid peroxidation; impaired antimicrobial defenses; CS equivalent serum cotinine levels; inflammatory response in airway |
| Garcia-Arcos et al. (46) | Mouse | Whole body | 4 mo, 1 h daily | Nicotine: 18 mg/ml | Compressed air nebulizer | Increased airway hyperreactivity; distal airspace enlargement; increased lung mucin production, inflammatory cytokines, proteases |
| McGrath-Morrow et al. (94) | Neonatal mice | Whole body | 10 days, 20 min daily | Nicotine: 18 mg/ml | Joytech 510-T | Decreased weight gain; elevated plasma and urine cotinine; impaired alveolar development |
| Shivalingappa et al. (115) | Mouse | Whole body | 3 × 1 h daily | Nicotine: 25 mg/ml | Vibrational nebulizer | Increased lung lysate ubiquitin; evidence for impaired autophagy |
| Larcombe et al. (74) | 4-wk old Mice | Whole body | 8 wk of 1 h daily | Nicotine: 0 or 12 mg/ml + American Tobacco Flavor; varied ratio of VG to PG | iTaste MVP 2.0 | Increased responsiveness to methacholine despite no increase in inflammatory cells; lower lung volumes at fixed transmural pressure; more severe impairments with VG predominant excipient |
| Hwang (62) | Mouse | Nose only | 4 wk, 1 h daily | Nicotine: 24 mg/ml | Multiple | Increased BAL inflammatory cytokines; impaired antimicrobial defenses |
| Werley et al. (131) | Rat | Nose only | 28–90 days 15–160 min daily | Nicotine: 20 mg/ml + flavoring | MarkTen | Increased BAL protein, neutrophils, macrophages; BAL changes persisted for 7 wk; morphological changes in nasal epithelium, larynx, and lungs |
| Lim and Kim (81) | Mouse | Intratracheal instillation of diluted e-liquid | 10 wk, 2 times weekly | Nicotine: dosed at 1.3 mg/kg | N/A (intratracheal instillation) | Increased airway hyperresponsiveness to methacholine; increased BAL eosinophils and Th2 cytokines |
VG, vegetable glycerin; PG, propylene glycol; N/A, not applicable; CS, cigarette smoke; BAL, bronchoalveolar lavage.