According to an animal study, e-cigarette aerosol containing free-base nicotine caused more severe airway changes in young mice than nicotine salt.
Researchers investigated the long-term pulmonary effects of aerosol from third-generation e-cigarettes containing 24 mg/ml free-base nicotine and fourth-generation e-cigarettes containing 24 mg/ml nicotine salt, both in tobacco flavor, on young male and female mice. The 4–6-week-old rodents were exposed to clean air or one of the two types of aerosol for one hour daily for three months, with similar particle sizes (approximately 274 nm median size) and solid concentrations (approximately 0.4 mg/puff).
The study showed that despite identical exposure levels, free-base nicotine caused more severe airway remodeling in young mice than nicotine salt. In male animals, significantly increased collagen deposition, persistent restrictive lung function decline, macrophage infiltration, and upregulated gene expression associated with fibrosis and inflammation were observed. Both types of exposure modified lung structure based on increased mean linear intercept, yet nicotine salt induced milder functional impairment despite higher serum cotinine levels.
The authors highlighted that the degree of pulmonary toxicity depends on the chemical form of the nicotine and noted sex differences, as male mice proved more susceptible to adverse airway effects.
In brief
- A three-month study compared the effects of 24 mg/ml concentration free-base nicotine and nicotine salt on young mice.
- Free-base nicotine triggered a more severe inflammatory response, collagen deposition, and restrictive lung function deterioration, especially in males.
- Nicotine salt resulted in milder functional lung changes despite providing higher blood serum cotinine levels.
Source: PubMed (pubmed.ncbi.nlm.nih.gov)
This summary was created by artificial intelligence based on the original article.