FEATURES OF APOPTOSIS-REGULATORY PROTEINS EXPRESSION IN NEURONS OF WHITE RATS AT EXPOSURE TO NANOSILVER ENCAPSULATED IN A POLYMER MATRIX

Results of a comparative analysis of apoptosis-regulating proteins caspase-3 and bcl-2 expression in nerve tissue cells of outbred white rats are reported. . An immunohistochemical investigation into the white rats nerve tissue was performed 9-days after administration of nano biocomposites consisting of silver nanoparticles encapsulated in a matrix of arabinogalactan, a natural biopolymer. and synthetic one – poly-1-vinyl-1,2,4-triazole. White rats were examined in 2 stages: half of the rats from each group was sacrificed immediately after exposure (early term) and the rest of rats- 6 months after the end of exposure (delayed term). It was found out that the expression activity of apoptosis regulatory protein at exposure to innovative nano biocomposites had its special features depending on a preparation administered and time of inspection. The examination immediately after subacute administration of arabinogalactan, a nano biocomposite, showed that the content of apoptotic and anti-apoptotic proteins caspase-3 and bcl-2 increased in the nerve tissue cells of white rats brain. Identified results showed activation of apoptotic processes as early as on the 10th day after the end of exposure to nano biocomposites. In a delayed examination period, a number of hyperchromic and normal cells expressing the protein caspase-3, became even higher testifying to intensification of apoptosis over time under impact of nanocomposite based on the natural matrix of arabinogalactan. A significant increase in number of neurons expressing bcl – 2 was also revealed in preparations but the protective effect of this protein was not fully realized. Thus, when comparatively assessing biological effects of polymer nano biocomposites containing nano silver in natural and synthetic matrices of arabinogalactan and poly-1-vinyl-1,2,4-triazole, it was found out that disorders in neuron subcellular organization emerge at only administration of nanobiocomposite in natural matrix of arabinogalactan . Analysis of results of expression of apoptosis-regulating proteins at administration of argentum polyvinyl triazola (PVT) to white rats did not reveal any changes as compared to administration of pure polymer matrix that could attest to activation of apoptosis in nerve cells throughout the observation period. Changes in indices had multidirectional character, an increased content of bcl-2 protein that was effectively involved in the regulation of apoptosis process was not observed , as well as increased expression of the protein caspase-3, which testified to irreversible changes in cells at apoptosis induction.

immunohistochemistry, arabinogalactan, poly-1-vinyl-1, 2, 4-triazole, nano silver, apoptosis, laboratory animals, brain