Structure Features and Sensitivity of Hippocampal Cells to the Endothelial Vascular Growth Factor Against the Background of Intranasal Administration of Titanium Dioxide Nanoparticles

The aim: to study the structural characteristics and sensitivity of rat hippocampal cells to the endothelial growth factor of vessels against intranasal administration of nanoparticles (NP) TiO 2 (rutile form, 40–60 nm, daily, 10 mg/kg animal body weight, 30 days). Material and methods. When studying the effect of the studied NP on the morphological characteristics of the hippocampus, animals of the experimental group were intranasally injected daily with a suspension of NP TiO 2 (10 mg/kg body weight, 30 days), and the rats of the control group received distilled water in the same volume. Animals were removed from the experiment after 30 days of overdose of diethyl ether and the brain was removed for histological and electron microscopic examination. We used classical morphological approaches, electron microscopy and immunohistochemical staining with antibodies to the cell sensitivity marker, the receptor for endothelial vascular growth factor VEGFR-1 / Flt-1.The classical morphological approaches, the method of electron microscopy and immunohistochemical staining with antibodies to the marker of sensitivity of the receptor cells to the endothelial vascular growth factor VEGFR-1/Flt-1 were used. Results . It has been established that against the background of intranasal administration of NP TiO 2 in the pyramidal layer of CA 1 and CA 3 hippocampal fields, the density of neuronal packing decreases, the area of the nucleus and the pericarion of the cells decrease in comparison with the control. Ultrastructural changes were detected, indicating a damage to the structures of the energy and protein synthesis apparatus of neurons. Immunohistochemical study revealed an increase in the sensitivity of vascular endothelial cells and the hippocampal macroglia of the experimental group of animals to the endothelial factor of vascular growth. Conclusions . Intranasal management of NP TiO 2 leads to negative changes in the structural characteristics of the CA 1 , CA 3 hippocampal zones, ultramicroscopic features, and also to an increase in the sensitivity of a number of cells to VEGF, which indicates their possible neurotoxic effect.