An Analysis of the Role of Bioenergetic Processes under Radioprotective Effects Mediated by Alpha1-Adrenergic Agonists

An analysis of modern concepts of the mechanism of the antiradiation effect of alpha1-adrenergic agonists, which are of great interest in clinical practice of radiochemotherapy in cancer patients, has been carried out. The first explanation of their mechanism of action is based on the role of circulatory hypoxia in radiosensitive tissues due to the vasoconstrictor effect of alpha1-adrenergic agonists. During further study of the real decrease in oxygen tension in tissue under circulatory hypoxia, it was found that it is insufficient to fully provide the observed increase in the body’s radioresistance under their influence. The second important fact is that in the course of a decrease in the baseline oxygen consumption per unit of body weight when passing from small to large animals, the antiradiation effect of circulatory and hypoxic hypoxia decreases due to the great adaptive abilities in maintaining oxygen homeostasis of the cell under these conditions. This point is directly related to humans. To explain the high radiation protection in large animals under the influence of alpha1-adrenergic agonists, a hypothesis on the development of acute tissue hypoxia due to the intensification of oxygen consumption under alpha1-adrenergic receptor stimulation has been proposed. The third thesis is that alpha1-adrenergic agonists can stabilize mitochondrial homeostasis under exposure to radiation, thereby reducing the probability of radiation apoptosis of cells and maintaining optimal tissue functioning. All three noted components of the mechanism of the antiradiation effect of alpha1-adrenergic agonists can interact with each other, leading to high protection. The role of each component can change and dominate for each specific scenario of their practical application. © 2021, Pleiades Publishing, Inc.