Effect of ionizing radiation on the synthetic activity of blood system cells in ground squirrels in different physiological states

Karnaukhova, N. A.; Sergievich, L. A.; Ignat’ev, D. A.; Karnaukhov, V. N.

doi:10.1134/s0006350908010090

Cited by 5 publications

(3 citation statements)

References 9 publications

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“…Mice and rats, which do not hibernate but their body temperature can be lowered to ~28 °C with chlorpromazine, exhibited 73–100% increased survival after TBI doses of 7–8 Gy under hypothermic conditions compared to normal [12–14]. Various protective physiological and biochemical effects have been reported in the tissues of hypothermic irradiated animals, including increased survival of intestinal crypt cells [11], less pronounced decrease in apoptosis and necrosis of blood lymphocytes, bone marrow hematopoietic cells, and thymus cells [21,22], more resistant proteinsynthesis in neurons, and less loss of cellular structural integrity [23,24].…”

Section: Introduction: Why Study Hypothermia In Radiation Biology?mentioning

confidence: 99%

Hypothermia postpones DNA damage repair in irradiated cells and protects against cell killing

Baird¹,

Dickey²,

Nakamura³

et al. 2011

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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Hibernation is an established strategy used by some homeothermic organisms to survive cold environments. In true hibernation, the core body temperature of an animal may drop to below 0°C and metabolic activity almost cease. The phenomenon of hibernation in humans is receiving renewed interest since several cases of victims exhibiting core body temperatures as low as 13.7°C have been revived with minimal lasting deficits. In addition, local cooling during radiotherapy has resulted in normal tissue protection. The experiments described in this paper were prompted by the results of a very limited pilot study, which showed a suppressed DNA repair response of mouse lymphocytes collected from animals subjected to 7-Gy total body irradiation under hypothermic (13°C) conditions, compared to normothermic controls. Here we report that human BJ-hTERT cells exhibited a pronounced radioprotective effect on clonogenic survival when cooled to 13°C during and 12h after irradiation. Mild hypothermia at 20 and 30°C also resulted in some radioprotection. The neutral comet assay revealed an apparent lack on double strand break (DSB) rejoining at 13°C. Extension of the mouse lymphocyte study to ex vivo-irradiated human lymphocytes confirmed lower levels of induced phosphorylated H2AX (γ-H2AX) and persistence of the lesions at hypothermia compared to the normal temperature. Parallel studies of radiation-induced oxidatively clustered DNA lesions (OCDLs) revealed partial repair at 13°C compared to the rapid repair at 37°C. For both γ-H2AX foci and OCDLs, the return of lymphocytes to 37°C resulted in the resumption of normal repair kinetics. These results, as well as observations made by others and reviewed in this study, have implications for understanding the radiobiology and protective mechanisms underlying hypothermia and potential opportunities for exploitation in terms of protecting normal tissues against radiation.

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Section: Introduction: Why Study Hypothermia In Radiation Biology?mentioning

confidence: 99%

Hypothermia postpones DNA damage repair in irradiated cells and protects against cell killing

Baird¹,

Dickey²,

Nakamura³

et al. 2011

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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“…It should be noted that reticulocytes have a much larger MCV than mature erythrocytes (Stevens-Hernandez et al, 2022). According to Gulevsky and Shchenyavsky (2014), the level of reticulocytes significantly increased in the blood of ground squirrels in the spring (April), which is consistent with an increase in the synthetic activity of the bone marrow (Karnauhova et al, 2008). An osmoscan at a high shear stress of 10−15 Pa represents a change in the deformability indices of all population RBCs.…”

Section: Discussionmentioning

confidence: 77%

Seasonal changes in blood rheology in little ground squirrels

et al. 2023

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The annual cycle of small ground squirrels (Spermophilus pygmaeus) consists of 2 periods: wakefulness (spring−autumn) and hibernation (winter). During the active period, ground squirrels breed (spring), accumulate fat reserves (summer) and prepare for hibernation (autumn). We suppose that the rheological properties of blood and the deformability of erythrocytes can change in different seasons of the animal's wakefulness period to adequately provide tissues with oxygen. The aim of this study was to identify possible adaptive changes in erythrocyte deformability and erythrocyte indices in ground squirrels during their active period. The deformability of erythrocytes was studied by ektacytometry in an osmotic gradient. It was found that in spring, after the arousal of ground squirrels, erythrocytes have the highest deformability (El_max), hydration (O_hyper), water permeability (El_min) and osmotic stability (∆O). In summer, compared with spring, the deformability of erythrocytes decreases, and the average volume of erythrocytes (MCV) also decreases. In autumn, before hibernation, the integral deformability of erythrocytes, their hydration, as well as the range of osmotic stability of erythrocytes increases relative to the summer period. In summer and autumn, in contrast to spring, the average concentration of hemoglobin in the erythrocyte (MCHC) increases. At low shear stress (1 Pa) in summer and autumn, osmoscan becomes a pronounced polymodal form, indicating a change in the viscoelastic properties of ground squirrel erythrocyte membranes. Thus, for the first time, we discovered seasonal variability in the deformability of ground squirrel erythrocytes, which is consistent with the spring‐summer activity of animals and preparation for hibernation.

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“…We have shown earlier [12,20,21] that changes in the cell synthetic activity generally precede those in the cell numbers of blood system organs. It may thus be thought that α in spleen could have transiently declined within a day after 5 Fu injection (i.e., by the day of BMT).…”

Section: Discussionmentioning

confidence: 84%

Use of fluorescence microspectral method for studying bone marrow EGFP+ cell transplantation in 5-fluorouracil-treated mice

et al. 2014

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In this paper the experimental results of bone marrow transplantation from C57BL/6-Tg(ACTB EGFP)1Osb/J transgenic mice into C57BL/6 mice subjected to 5 fluorouracil treatment are represented. It has been shown that EGFP + cell engraftment in bone marrow, spleen and thymus of host mice after 5 Fu treatment significantly increased. More long term engraftment was recorded after transplantation between closely related donors and 5 fluorouracil treatment hosts. We have also obtained data on differences in the dynamics of EGFP + cell engraftment in host investigated organs. To assess the effect of the donor's bone marrow cells on the host immune system, functional activity of the synthetic apparatus (synthetic activity) of cells in bone marrow, spleen, thymus and blood have been investigated with fluorescence microspectral method. The results obtained allow of improving techniques for bone marrow transplantation without host irradiation in order to minimize the adverse effects.

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Effect of ionizing radiation on the synthetic activity of blood system cells in ground squirrels in different physiological states

Cited by 5 publications

References 9 publications

Hypothermia postpones DNA damage repair in irradiated cells and protects against cell killing

Hypothermia postpones DNA damage repair in irradiated cells and protects against cell killing

Seasonal changes in blood rheology in little ground squirrels

Use of fluorescence microspectral method for studying bone marrow EGFP+ cell transplantation in 5-fluorouracil-treated mice

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