State Institution “Kundiiev Institute of Occupational Health of the National Academy of Medical Sciences of Ukraine”, Kiev, Ukraine
Introduction. Among metal nanoparticles (NPs), nanoparticles of iron oxides (NPIO) take a special place as they are widely used in agriculture, medicine and pharmacy. The exposure to NPIO can occur at the stage of production, use and disposal as well as in special conditions at enterprises of ferrous and non-ferrous metallurgy, while cutting and welding metal constructions. Taking into account high biological activity of NPIO, the nature of their influence on different organs and systems of the body is not still well studied.
The purpose of the study is to determine morpho-functional changes in the internal organs of rats (heart, liver, kidneys, pancreas) under a long-term administration of NPs of iron oxide (Fe2O3) of different size into peritoneum.
Materials and methods. The study was conducted on 24 Wistar male rats of 150-180 g body weight, divided into 3 groups: 1 control and 2 experimental groups. Colloidal solutions of Fe2O3 with NPs of 19 nm and 75 nm were used in the experiment. The solutions were administered into abdominal cavity for 5 days a week. Morphological studies of the internal organs (heart, liver, kidneys, pancreas) were conducted using standard and special histological and histochemical methods. Also, biochemical indices, characterizing the functional state of liver, kidneys as well as lipid, carbohydrate and protein metabolism were determined, using a biochemical analyzer VITLAB FLEXOR E (The Netherlands) and standard test kits Elitech (France).
The results of the study. It has been established that the prolonged administration of Fe2O3 NPs into abdominal cavity of rats is accompanied by accumulation of small crystal-like inclusions in the cytoplasm of cardiomyocytes, hepatocytes, and cells of nephrothelium. This points to cumulation of Fe2O3 NPs in the target organs which causes dystrophic and necrobiotic processes in cells, demonstrating a toxic effect. The cardio-vasotoxic effect of Fe2O3 NPs was manifested by the disorder of the blood circulation in the microvasculature channel, as evidenced by the blood stasis in the capillary and vein lumens. Liver damages were manifested by disorders in antitoxic and metabolic functions, and metabolic processes. More pronounced changes in all parameters occurred in animals exposed to Fe2O3 NPs with19 nm, indicating their great toxicity. The effect of Fe2O3 NPs of both sizes on kidneys of experimental rats was accompanied by the plenipotentiary of capillaries of renal glomeruli, expansion of lumens of the renal capsule and granular dystrophy of cells of the proximal epithelium, pointing to disorders of processes of the glomerular filtration and tubular reabsorption. In the pancreas, the toxic effect was manifested by disorders in the blood circulation and dystrophic changes in acinar cells and insulocites of pancreatic islands, showing the decrease in their functional activity, more characteristic for NPs of 19mn.
Conclusion. Nanoparticles of Fe2O3, under in long-term administration into the abdominal cavity of rats, are cumulated in the target organs (heart, liver, kidneys) and cause in them a wide range of structural and functional changes, indicating their cardiovascular, hepatotoxic and nephrotoxic effects.
Key words: NPs of Fe2O3, liver, kidneys, pancreas, heart, metabolic processes.
ORCID ID of authors and their contribution to the preparation and writing of the article:
Lugovsky SP (ORCID ID 0000-0002-3948-7026) - analysis of research results, formulation of conclusions;
Dmitrukh NM (ORCID ID 0000-0001-9161-3889) - analysis of research results, formulation of conclusions, preparation of material for printing;
Didenko MM (ORCID ID 0000-0002-2540-2685) - histological examination and analysis of results, preparation of material for printing;
Bakalo LV (ORCID ID 0000-0003-3295-8937) - performing experimental biochemical and histological studies;
OS Lagutina (ORCID ID 0000-0003-0723-1293) - performing experimental biochemical studies, conducting statistical data processing;
Melnik NA (ORCID ID 0000-0003-1271-4476) - performing experimental histological examinations, preparation of material for printing.