N 2 (199) 2026. P. 9–15

METABOLIC AND MORPHOLOGICAL CHANGES IN RAT TISSUES UNDER THE EFFECT OF ELECTRONIC CIGARETTES

I. R. Gridina, S. S. Chernadchuk, I. L. Ryzhko

Odesa National Medical University, Odesa, Ukraine
Odesa I. I. Mechnikov National University, Odesa, Ukraine

DOI 10.32782/2226-2008-2026-2-1

Introduction. Electronic cigarettes are widely used as a potentially less harmful alternative to conventional smoking, generating aerosol without exothermic combustion. Exposure to e-cigarette aerosols increases reactive oxygen species and lipid peroxidation products, which modify key metabolic enzymes and disrupt energy and lipid homeostasis. These effects are reflected in elevated lactate dehydrogenase (LDH) and creatine kinase (CK) activities, altered glucose levels, and morphological tissue changes confirmed by histology.

Aim of the study. To establish organ-specific changes in energy and lipid homeostasis indicators, as well as morphological alterations in rat tissues under conditions of chronic exposure to electronic cigarette aerosols.

Materials and Methods. Twenty adult male Wistar rats were divided into the experimental (n = 10) and the control (n = 10) groups. Experimental animals were exposed to aerosol from an Elf Bar 1500 Ultra e-cigarette for 20 minutes daily over three months; animals in the control group were not exposed. Animals were euthanized one hour after the final session, and tissue samples from the lungs, liver, heart, kidneys, and brain were collected for biochemical assays and histological examination.

Results. Chronic exposure increased LDH and CK in lungs and liver, indicating anaerobic glycolysis activation and cytolytic injury, accompanied by inflammation, edema, and alveolar disruption. Reduced tissue glucose and suppressed enzymatic activity in the heart and kidneys were associated with microcirculatory disturbances. Lipid accumulation correlated with inflammatory and edematous reactions, while brain histology revealed increased vascular permeability.

Conclusions. Chronic e-cigarette aerosol exposure induces organ-specific metabolic and structural alterations, disrupting energy and lipid metabolism and causing histological damage, most pronounced in the lungs.

Keywords: electronic cigarettes, biochemical markers, toxicity, organ-specificity, histology.

REFERENCES

  1. Pandarathodiyil AK, Ramanathan A, Garg R, et al. Lactate Dehydrogenase Levels in the Saliva of Cigarette and E-Cigarette Smokers (Vapers): A Comparative Analysis. Asian Pac J Cancer Prev. 2021;22(10):3227–3235. https://doi.org/10.31557/ APJCP.2021.22.10.3227.
  2. De Martin S, Gabbia D, Bogialli S, et al. Refill liquids for electronic cigarettes display peculiar toxicity on human endothelial cells. Toxicol Rep. 2021;8:456–462. https://doi.org/10.1016/j.toxrep.2021.02.021.
  3. Damay VA, Setiawan LR, Akbar MR, et al. Electronic cigarette and atherosclerosis: A comprehensive literature review of latest evidence. Int J Vasc Med. 2022;2022:4136811. https://doi.org/10.1155/2022/4136811.
  4. Okafor CN, Okafor N, Kaliszewski C, Wang L. Association between electronic cigarette and combustible cigarette use with cardiometabolic risk biomarkers among U.S. adults. Ann Epidemiol. 2022;71. https://doi.org/10.1016/j.annepidem.2022.02.002.
  5. Magna A, Polisena N, Polisena L, et al. The hidden dangers: E-cigarettes, heated tobacco, and their impact on oxidative stress and atherosclerosis. Antioxidants (Basel). 2024;13(11):1395. https://doi.org/10.3390/antiox13111395.
  6. Liu X, Mustonen A, Zheng W, Sivasankar MP, Durkes AC. Cigarette Smoke Exposure to Pig Larynx in an Inhalation Chamber. J Voice. 2019;33(6):846–850. https://doi.org/10.1016/j.jvoice.2018.05.005.
  7. Roxlau ET, Pak O, Hadzic S, et al. Nicotine promotes e-cigarette vapor-induced lung endothelial permeability and inflammation. Eur Respir J. 2023;61(6):2201305. https://doi.org/10.1183/13993003.00951-2022.
  8. Bondarchuk TI, Kobylynska LI, Nasadiuk KhM, et al. Biokhimichni pokaznyky v normi i pry patolohii [Biochemical parameters in normal conditions and pathology]. 2nd ed. Kyiv: VSV Medytsyna; 2025. 415 p. (In Ukrainian).
  9. Prylutskyi YuI, Ilchenko OV, Tsymbaliuk OV, Kosterin SO. Statystychni metody v biolohii: pidruchnyk [Statistical methods in biology: textbook]. Kyiv: Naukova dumka; 2017. 216 p. (In Ukrainian).
  10. Vareniuk IM, Dzerzhynskyi ME. Metody tsyto-histolohichnoi diahnostyky. Kyiv: Interservis; 2019. 256 p. (In Ukrainian).
  11. Assiri MA, Al Jumayi SR, Alsuhaymi S, et al. Electronic cigarette vapor disrupts key metabolic pathways in human lung epithelial cells. Saudi Pharm J. 2024;32(1):101897. https://doi.org/10.1016/j.jsps.2023.101897.
  12. Effah F, Adragna J, Luglio D, Bailey A, Marczylo T, Gordon T. Toxicological assessment of E-cigarette flavored E-liquids aerosols using Calu-3 cells: A 3D lung model approach. Toxicology. 2023;500:153683. https://doi.org/10.1016/j. tox.2023.153683.
  13. Caruana V, Giles BH, Kukolj N, et al. Chronic exposure to e-cigarette aerosols potentiates atherosclerosis in a sex-dependent manner. Toxicol Appl Pharmacol. 2024;492:117095. https://doi.org/10.1016/j.taap.2024.117095.
  14. Ashakumary L, Vijayammal PL. Effect of nicotine on lipoprotein metabolism in rats. Lipids. 1997;32:311–315. https://doi.org/ 10.1007/s11745-997-0038-8.
  15. Ismail NA, Nabila T, Ramadhani AS, Ahsani DN. Electronic and conventional cigarette exposure aggravate metabolic parameters in high-fat diet-induced rats. Open Access Maced J Med Sci. 2022;10(A):841–847.
  16. Keith R, Bhatnagar A. Cardiorespiratory and immunologic effects of electronic cigarettes. Curr Addict Rep. 2021;8:336–346. https://doi.org/10.1007/s40429-021-00359-7.
  17. Zima K, Bogucka A, Wojtas M, Zabielska-Kaczorowska M. Immunological effects of electronic cigarette use. Clin Rev Allergy Immunol. 2025;68(1):9. https://doi.org/10.1007/s12016-025-09026-5.
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