Arctic Stress: Mechanisms and Experimental Models

Abstract

Humans stay in the Polar regions results in the development of stress caused by a combination of factors such as low air temperature, hypodynamia, hypoxia, and disruption of the daylight cycle. All this strongly indicates the increased requirements for health protection and prevention of morbidity in the population of the Arctic. The problem is topical of search for optimal biological models of Arctic stress intended for preclinical testing of pharmacological and dietary correction of its consequences. Aim analysis of literature data on the pathophysiological mechanisms of polar stress, existing methods for its modeling in the experiment, informative biomarkers and prospects for dietary correction. Selection by keywords and analysis of literary sources using PubMed, Web of Science and Scopus online resources for the period, mainly, 20102022. The reaction to adverse environmental conditions in the Arctic is based on universal mechanisms associated with the excitation of midbrain centers (primarily the hypothalamus) with the development of a subsequent hormonal response from peptide hormones, corticosteroids, catecholamines, and thyroid hormones. The secondary targets of these effects are muscle tissue, endothelium, white and brown adipose tissue, cells of the immune system, in which changes occur aimed at neutralizing external adverse effects. A number of laboratory animal models have been developed to reproduce conditions associated with polar stress, including various types of acute, subacute and chronic cold exposure, as well as its combination with forced physical activity and additional stress factors. Sensitive biomarkers that allow monitoring the severity of polar stress are, firstly, the content of corticosteroids, catecholamines, neuropeptides, micro-RNA (miR-210) in blood plasma, organs and compartments of the brain, expression levels of uncoupling proteins (UCP) in brown adipose tissue, indicators of oxidative stress (lipoperoxide and malondialdehyde content, activity of antioxidant defense enzymes GPX, GR, SOD, catalase and others), levels of bioantioxidants (vitamin E, ascorbic acid, carotenoids, GSH), cytokines and chemokines, including IL-1, IL-6, IL-10, IL-17, IL-33, RANTES, FGF21 and various forms of their receptors, gene expression of signaling molecules (proteinkinases). In the issue of dietary correction of disorders caused by polar stress, the main place is given to the use of dietary antioxidant factors (vitamins E and C, selenium, zinc, coenzyme Q10, cinnamic acids and bioflavonoids). The data available in the world literature form the basis for further study of the molecular mechanisms of polar stress and pathogenetically substantiated methods of its dietary correction.