Abstract:
Mechanisms of interaction of ionizing radiation with biological objects are a chain of
successive physical and physico-chemical changes, which manifest themselves in the form of
excitation, primary and secondary ionization of molecules. Biosynthesis of ATP, which is carried out
by a system of oxidation-reduction enzymes localized in the inner membrane of mitochondria - the
respiratory chain, belongs to the vital processes that are directly disturbed under the action of ionizing
radiation. The high degree of damage to this system is due to the significant radiosensitivity of metalcontaining enzymes. The purpose of the work is to study the formation of the adaptive response of
muscle tissue of sexually mature rats to the influence of ionizing radiation at a dose of 0.5 Gy. It was
concluded that a day after irradiation with the dose of 0.5 Gy, the content of contractile proteins in
skeletal muscle decreases slightly. On the 15th day, the content of contractile proteins began to
decrease. By the 30th day, the content of contractile proteins decreased by 22.9% for myosin, by more
than 11% for actin, and by 7 and 8% for troponin and tropomyosin, respectively, compared to the
values of the intact group. A similar picture is observed in the cardiac muscle. Mg2+,Ca2+-ATP-ase
activity of actomyosin, starting from the 1st day was shown to be increased in both the skeletal and
cardiac muscles, reaching its peak in the cardiac muscle on the 15th day, in contrast to the skeletal muscle, where this indicator reached its peak on the 7th day. The authors conclude that irradiation of
sexually mature animals with the dose of 0.5 Gy forms an adaptive response that is accompanied by
an increase in Mg2+,Ca2+-ATP-ase activity due to the formation of a strong form of binding between
F-actin and myosin, actin monomers go into the typical for actomyosin “turned on stage”, and the
myosin heads acquire an ordered orientation in the muscle fiber. According to author’s idea, the data
obtained indicated the benefit and reasonability of using in post-radiation dysfunctions complex
pharmacological treatment drugs that are able to normalize intracellular homeostasis, eliminate
probable acidic changes initiated by radiation exposure, activate the processes of intramuscle energy
generation and which have protective properties in relation to the muscular system.
