Kurilko J. Experimental determination of the cord blood biopreparation influence on the thyroid function and the immune system in rats under the modeling autoimmune thyroiditis conditions

This dissertation focuses on substantiating the effectiveness of cord blood serum, a biological preparation, in correcting disorders of the thyroid and immune systems in rats experiencing experimental autoimmune damage to the thyroid gland. The study aims to validate the effectiveness of cord blood serum in addressing structural-functional disorders of the thyroid gland and immune system features in rats with simulated autoimmune thyroiditis, along with its correction. Research methods encompassed physiological, pathophysiological, biochemical, immunological, histological, hematological, and statistical analyses. The research demonstrated that cord blood serum and L-thyroxine positively affected the structure and function of the thyroid gland in rats with autoimmune thyroiditis. A distinct restorative effect of cord blood serum on the immune system of rats was observed for the first time, revealing its direct and indirect positive influences on immunity and homeostasis. Novel findings unveiled fundamentally different mechanisms of action between cord blood serum and L-thyroxine on the structure and functions of the thyroid gland in rats with induced autoimmune thyroiditis. The action of cord blood serum led to the normalization of immunoglobulins M, G, A, and circulating immune complexes, confirming its immunomodulatory activity for the first time. Distinct anti-inflammatory mechanisms were noted: L-thyroxine reduced pituitary stimulation of the thyroid gland with exogenous thyroxine administration, while cord blood serum contained numerous biologically active compounds, including anti-inflammatory cytokines and alpha-fetoprotein. Both drugs exhibited antioxidant activity, with L-thyroxine more effectively impacting peroxidation processes and cord blood serum proving to be a more powerful modulator, contributing to the restoration of the enzyme link of antioxidant protection with prolonged effect. Theoretical and experimental results support the positive effect of both drugs, particularly cord blood serum, which showed a more prolonged and normalizing effect compared to the reference drug. These experimental findings could form the basis for further exploration of cord blood serum as an initiator of immunomodulatory mechanisms to correct immunosuppression in autoimmune thyroiditis, suggesting its potential as a biological preparation in practical medicine, particularly in endocrinology.