Long-Term Persistence of Increased Number of γH2AX Peripheral Blood Lymphocytes in Monkeys Exposed to Negative Factors of Space Flights: Ionizing Radiation and Simulated Hypogravity.

We studied the influence of ionizing radiation and hypogravity as negative factors of space flights on DNA damage in peripheral blood lymphocytes of rhesus monkeys at different times after exposure (from 1 to 446 days). The proportion of cells with high numbers of DNA double-strand breaks (DSB), positive for the surrogate DSB marker-protein γH2AX, was monitored using flow cytometry. Some animals were exposed to 7-day antiorthostatic hypokinesia simulating hypogravity, the others to a combined effect of antiorthostatic hypokinesia, whole-body γ-irradiation (2.

Effects of combined exposure to modeled radiation and gravitation factors of the interplanetary flight: Monkeys' cognitive functions and the content of monoamines and their metabolites; cytogenetic changes in peripheral blood lymphocytes.

In a study on primates (Macaca mulatta), neurobiological and radiobiological effects have been studied of the synchronous combined action of 7-day antiorthostatic hypokinesia and exposure of the monkeys' head first to γ-rays during 24 h and then to accelerated C ions. The neurobiological effects were evaluated by the cognitive functions which model the basic elements of operator activity and the concentration of monoamines and their metabolites in peripheral blood. The radiobiological effects were evaluated by the chromosomal aberration and DNA double-strand break (DSB) yield in peripheral blood lymphocytes.

Combined Effects of Irradiation and Hindlimb Suspension on Erythroid Lineage Precursors from Rat Bone Marrow.

Erythroid precursors from the femoral bone marrow of Wistar rats were characterized after 30-day hindlimb suspension, fractionated γ-radiation, and their combination. After hindlimb suspension, the total content of myeloid CFU decreased; activity of erythroid differon also considerably suppressed, which manifested in a decrease in the number of erythroid burst-forming units and area of colonies formed by erythrocyte precursors. After irradiation and combined exposure to these two factors, no significant differences from the control were revealed; optical density of formed colonies slightly increased in all experimental groups.

An investigation of the single and combined effects of hypogravity and ionizing radiation on brain monoamine metabolism and rats' behavior.

Background: Ionizing radiation and hypogravity can cause central nervous system (CNS) dysfunctions. This is a key limiting factor for deep space missions. Up until now, the mechanisms through which they affect the neural tissue are not completely understood.

Neurochemical insights into the radiation protection of astronauts: Distinction between low- and moderate-LET radiation components.

Radiation protection of astronauts remains an ongoing challenge in preparation of deep space exploratory missions. Exposure to space radiation consisting of multiple radiation components is associated with a significant risk of experiencing central nervous system (CNS) detriments, potentially influencing the crew operational decisions. Developing of countermeasures protecting CNS from the deleterious exposure requires understanding the mechanistic nature of cognitive impairments induced by different components of space radiation.