Martynova Y. Effect of rhythmic extreme cooling and cord blood on state of neurohumoral regulation systems in dynamics of rats' aging.

The research object was the structural and functional state of animals’ neurohumoral regulation systems in dynamics of aging, after rhythmic extreme whole body cooling (RE WBC), injection of cryopreserved cord blood nucleated cells (cCBNCs) and combined use of them. The research aim was to determine an impact of RE WBC, cCBNCs and their combined application on the structural and functional state of neurohumoral regulation systems in the dynamics of aging in rats. The research methods were as follows: cryobiological (a method of RE WBC, at –120 °С); electrophysiological (an electrocardiogram record with further spectral analysis of heart rate variability to estimate the state of both adaptive reserves and neurohumoral regulation of the animal’s body); histological (with morphometric parameters evaluation) and electron microscopic ones to define the structure of myocardium tissue and vessels as one of the key markers, reflecting the aging process; enzyme immunoassays to define the concentrations of thyroid (thyroxine, triiodothyronine) and sex (testosterone, estradiol and dehydroepiandrosterone sulfate) hormones in blood serum, the ratio of testosterone to estradiol as an index of androgen-estrogen balance; spectrophotometric one to study the content of terminal metabolites of nitric oxide in blood serum; statistical methods to analyze the experimental data. The structural and functional changes taking place in the regulatory systems of an animal’s body after the use of RE WBC, injection of cCBNCs and their combination in the dynamics of natural aging, starting from the 6 months age, have been estimated for the first time. It has been for the first time found, that the combined use of RE WBC and cCBNCs during the life cycle of animals could maintain for a long time the “young” rhythm of neurohumoral effects on the body, promoted the implementation of the hormonal link of the “antiaging”, stimulated the synthesis of nitric oxide in case of its deficiency, activated metabolic and synthetic processes at microscopic and submicroscopic levels.