In an experiment to study radiation "bystander effects" (BEs) at the interorganismic (systemic) level, we use mice irradiated at a dose of 3 Gy and mice that are not irradiated, bystanders, kept together. In the irradiated animals, on the 3rd and 60th days, when kept without a partition, and on the 14th day when kept in cells with and without a partition, a statistically significant decrease in the frequency of normal chromatophilic (oxyphilic) erythrocytes (NCEs) with micronuclei is revealed when compared with the gamma control. In the nonirradiated bystander-mice, kept with the irradiated mice in a cage with a partition on the 14th day and in a cage without a partition on the 60th day, a tendency to exceed the micronucleus (MN) frequency of the erythrocytes' values in the biocontrol is revealed. Based on the data obtained in this experiment, it is assumed that the radiation BE has the opposite character; i.e., nonirradiated organisms are able to reduce the radiation effects in irradiated individuals: the "rescue effect."

This paper presents the first results of research and observations within the framework of the Integrated Project for the assessment of radiation-induced nontargeted effects. The remote bystander effect, related to nontargeted effects, is one of the least studied phenomena in terms of manifestations and mechanisms. The international laboratory practice with respect to this phenomenon commenced with demonstration of the bystander effect in fish and other aquacultures. Our studies have revealed changes similar to radiation-induced pathologies in nonirradiated mice kept for three months in contact with the irradiated species (exposed to a 3 Gy γ-ray dose). Changes in behavioral responses, a statistically significant trend for decreasing spleen weight ( r = –0.416; p = 0.048), an expanding area of alopecia ( r = –0.631; p = 0.001), and other anomalies are noted. Discussions on possible mechanisms of the phenomena refer to both A.M. Kuzin’s theory of radiotoxins (1966) and the interpretation of the hypotheses investigated by C. Mothersill (2010–2019). An assumption is made on the important role of derivatives of lipid peroxides in the formation of this effect. The results of these studies indicate the need for further investigation of the radiation-induced bystander effect by using the molecular and cellular methodological approaches.

To monitor human bioaging as a health integral index by blood plasma markers as a molar ratio for biochemically coupled monomers of intracellular lipofuscin, an intracellular polymeric aging pigment with free-radical crossed shifts, has been developed. Lipofuscin includes cell debris with catabolites of lipoperoxic cascade and lipid antioxidants. The latter were detected in the plasma samples of normal adults and children, as well as in Chernobyl clean-up workers (24-62 years old by 1990) with external total gamma-doses of 0.9-145 cSv for 4.2 years. Dynamics for bioaging markers as the molar ratio of blood levels of lipoperoxic catabolites to their antioxidants reflected normal physiologic peculiarities for the studied age periods: oxygen stress for newborns, adaptation during childhood, stability for the middle age and an increased lipoperoxidation (mainly for aging men) due to the age weakening of the antioxidant control. The ratio for the fractions of ma- lone dialdehyde (MDA), a lipoperoxic final catabolite, showed the increase of its binding by plasma proteins in proportions to calendar ages for the norm, as it is the case for lipofuscin; The graph of the age normal molar ratio of protein-bound MDA to the free one was pre-set for calibrations into the developed computer Program to calculate Relative Aging Velocities (Wrel) by bioage increments during the period of human exposure to radiation from the CAPS damage. Wrel were increasing logarithmically to the obtained doses if the total radiation exceeded 4 cSv and exceeded their normal velocities at 50 cSv 10 times or more. Slowing down of Wrel in relation to the calendar age increment was found if the sum doses were lower than 4 cSv. Levels of the studied plasma metabolites as their bioage Moles/Moles markers relative to their norms are dynamically stationary in contrast to the lipofuscin intracellular irreversible accumulation. Earlier it was shown that the decreased vitamin E and A levels with the increased lipoperoxic metabolite blood levels that indicate health consequences for the irradiated CAPS personell with related cytogenetic deviations, as well as for the adult population and children from radio-polluted regions, were restored to norms or corrected by adequate peroral therapy with bioantioxidants.

To study influence of "low radiodoses" on their early effects, the method to monitor peculiarities for human biochemphysic pathologies caused by technogenic chronic doses divided by natural constant radiation background doses (relative radiation loads as their ratios, RRL) has been developed. High radiolabile coupled system of harmful catabolites of the initiated lipoperoxic cascade with essential radioprotectors (vitamins A and E as natural antioxidants) as pathogenic significant test-objects were monitored. For exposed children low radiation technogenic doses were high enough as RRL to disturb and to dysregulate both systems. For evaluation of individual radiosensitivity significances of age for children especially, as of the biochemical status for both systems are shown. The approach permits to investigate pathologies of studied systems as primary factors for mechanisms of related radiogenic known somatic health secondary consequences and to use it for some important practical applications.

Children and adults affected by the Chernobyl accident suffer with lipoperoxic stress coupled with hypovitaminoses A and E, the syndrome and its radiogenic mechanisms described by the authors previously. The relation of these biochemical disturbances to somatic consequences on mutagenic and teratogenic levels caused by chronic low-dose irradiation of children into radiopolluted regions has been investigated. Either the rational approaches to prevent or/and to treat all pathologies indicated were tested. The radionuclide polluted regions had 1-5, 5-15 and 15-40 Ci/km2 by 137Cs. Unprotected newborns (without the therapy) had vA and vE levels about one third of normal ones for minimal radioloads, the vitamins lowered further for higher Da and/or Dm up to the deep hypovitaminoses or even avitaminoses. Increasing of LPC catabolites levels for children were correlated significantly with their stigmation levels. The therapy-protected newborns had normal ranges of all indices. However, unprotected newborns showed dramatic increase for all of radiogenic indices along with fall of vA and vE, and significant inverse correlations of the indices with retinol levels. The values of radiogenic indices showed hyperbolic-like rise along with growing of vA and vE deficits below their lower limits. The combination of radiogenic biochemical deviations evaluated for Chernobyl contingents is supposed to be the primary molecular mechanisms of somatic mutations and irreversible stigmation. The peroral polyvitamin therapy is proposed as the method of choice for prevention or normalization of revealed pathologies.