Structural changes of liver, kidneys and spleen in rats affected with nanoparticles of silicon dioxide

У статті представлено результати морфологічних змін печінки, нирок і селезінки щурів при дії наночастинок діоксиду кремнію. Встановлено, що вплив наночастинок БІ02 викликає мінімальні структурні зміни в печінці та нирках, які проявляються вогнищевою макрофагальною інфільтрацією, нерівномірним кровонаповненням тканини. В селезінці посилюється гемосидероз червоної пульпи та дрібновогнищева гіперплазія лімфоїдних фолікулів білої пульпи.В статье представлены результаты морфологических изменений печени, почек и селезенки крыс при действии наночастиц диоксида кремния. Установлено, что влияние наночастиц БІ02 вызывает минимальные структурные изменения в печени и почках, которые проявляются очаговой макрофагальной инфильтрацией, неравномерным кровенаполнением ткани. В селезенке усиливается гемосидероз красной пульпы и мелкоочаговая гиперплазия лимфоидных фолликулов белой пульпы.High dispersible nanostructured amorphous silicon dioxide (SiO2) is one of the main types of nanomaterial. It is everincreasingly used in food and medicine production, pharmacology and cosmetology. Under certain conditions, nanoparticles can have unfavourable, even toxic effect on the body. Nano-SiO2 may also affect animal and human cells in vitro. Even in low doses SiO2 nanoparticles can increase the production of inflammatory mediators, penetrate the cell nucleus and integrate into the phosphate frame of DNA, increase the level of active oxygen forms, influence the apoptosis processes. Changing the integrity of nucleus they may form intranuclear protein assembly that causes inhibition of replication, transcription and proliferation reactions. However, the biological effects of SiO2 nanoparticles in vivo in cases of oral intake have not been adequately studied. So, the study of nanostructured silicon dioxide toxicity is an urgent matter of nanotoxicology as well as of hygienic standardization. The aim of the study was to investigate morphological changes in liver, kidneys and spleen of rats in cases of intragastrical administration of SiO2 nanoparticles. 20 white outbred rats, 150-160 g in weight, which were kept on a standard vivarium diet, were used for the experiments. All manipulations with experimental animals were carried out in accordance with the bioethics principles. The test animals were divided into the following groups: the 1st - the intact rats (control); the 2nd - the rats administered intragastrically with nano-SiO2 colloidal solution at a dose of 50 mg/kg of body weight daily during 3 weeks. The intact animals were administered intragastrically with appropriate amount of normal saline daily. Euthanasia was performed by exsanguination under thiopental sodium anaesthesia in 21 days after the beginning of the experiment. Fragments of liver, kidney and spleen were used as the material for morphological studies. The histological examination of liver of the animals injected with SiO2 nanoparticles proved minor disorders that were manifested by uneven blood filling of great veins and sinusoids, and microfocal reticuloendothelial infiltration. In the cortex and medulla of kidneys moderate circulatory disorders developed, which were manifested by single stasis or spasms in blood vessels of arterial bed. Some of the cortical glomeruli experienced reduced blood filling or were ischemic; some hypertrophied endothelial cells were visualized in vessels lumens. Tubular basement membranes were not damaged; moderate oedema developed in interstitial tissues. In the white pulp of spleen a slight hyperplasia of lymphoid follicles was evidenced, which was manifested by the distention of reactive centres associated with hyperplasia of blast cells in germinal centres. Hyperplasia of red pulp was mainly associated with the increase in the number of sideroblasts and siderophages. The conclusion was drawn that SiO2 nanoparticles cause minimal structural changes in liver, kidneys and spleen