Effect of e-liquid from an electronic cigarette on the immune profile ofRana pipiens

Abstract

Little is known about the effect of electronic cigarette usage, although the number of people using the devices continues to increase. Here we examine the effect of e-liquid with different concentration levels of nicotine from an electronic cigarette on the immune profile of the northern leopard frog Rana pipiens. Using a Sigelei Mini 30W electronic cigarette, frogs were exposed to vapor for 10 minutes, 6 days a week, for 3 weeks. We hypothesized that e-liquid vapor would alter the leukocyte differentials and positively correlate with the nicotine concentration. Our results indicate mean lymphocyte percent decreased with both vapor exposures without nicotine (24.8 ± 0.0% in control vs. 6.0 ± 1.2%) and with nicotine (24.8 ± 0.0% in control vs. 5.8 ± 4.0%), whereas the mean neutrophil percent increased with vapor without nicotine (60.8 ± 0.0% in control vs. 89.4 ± 3.0%) and with nicotine (60.8 ± 0.0% in control vs. 90.3 ± 6.0%). There was a significant positive correlation between vapor exposure and total neutrophil differentials (r = 0.954, p 0.05). Monocyte, basophil, and eosinophil percentages also decreased in frogs that were exposed to vapor. These findings suggest that electronic cigarette smoke alters the immune profile of frogs with or without nicotine.