Abstract
Relevance of the topic: It is known that in the absence of thyroid hormones in the fetus and developing organism, impaired proliferation and differentiation of nerve cells in the brain can lead to cognitive disorders, neurodegenerative processes in the adult organism. Detection of autoantibodies to neurospecific proteins are biomarkers for early diagnosis of neurodegenerative processes, which allows early detection and treatment of changes in brain function in patients with hypothyroidism. Purpose of the research: To determine the dysfunction of neurospecific proteins such as GFAP, S-100, VGCC, NF-200 and MBP in the serum in experimental hypothyroidism and ways to restore them. Materials and Methods: To achieve the goal in the study, the state of hypothyroidism was modeled by injecting mercazolyl into the stomach for 21 days at a dose of 2.5 mg/100 g in white rats, then treated for 10 days. Experimental rats were divided into 6 groups: Group I - intact; Group II - rats with 21 days of hypothyroidism, Group III - rats with 30 days of hypothyroidism, Group IV - rats treated with L-thyroxine, Group V - rats treated with L-thyroxine and "neuroma", Group VI - L-thyroxine and rats treated with somazine. The enzyme-linked immunosorbent assay (ELI-N-Test) (Russia) determined the amount of autoantibodies to NF-200, GFAP, MBP, S100β, VGCC in the serum of rats. Serum levels of T3, T4 and TTG hormones were determined. Results: In experimental hypothyroidism, a significant increase in the amount of autoantibodies to various proteins of nerve tissue was observed on day 21 (group II) and day 30 (group III) relative to the intact group. In the serum of the treated group of animals there was a decrease in the amount of autoantibodies to neurospecific proteins. At the same time, L-thyroxine was more effective when used with neuroprotectors. Conclusions: The increase in the number of autoantibodies to neurospecific proteins indicates pathogenetic changes in immune system function and cognitive impairment and neurodegenerative processes due to hypothyroidism, and it is advisable to use a neuroprotective drug in combination with L-thyroxine to correct it.

Key words: hypothyroidism, L-thyroxine, GFAP, S-100, VGCC, NF-200, MBP, neurotropic autoantibodies.