[The early reaction of the neuroendocrine system to irradiation at high doses]. / Ranniaia reaktsiia neiroéndokrinnoi sistemy pri obluchenii v vysokikh dozakh.

It has been found that in 2 hours after the total gamma irradiation of rats at doses of 20 and 100 Gy the ACTH and glucagon levels in plasma increased by 5-6 and 10-12 times correspondingly. No significant changes in levels of plasma insulin and glucose have been revealed.

[Post-irradiation changes in the content of phospholipids and cyclic nucleotides in the mouse brain]. / Postradiatsionnye izmeneniia soderzhaniia fosfolipidov i tsiklicheskikh nukleotidov v golovnom mozge myshei.

The effect of ionizing radiation (5, 20, 100, 200 and 400 Gy) on the content of phospholipids and cyclic nucleotides in the brain tissue has been studied in experiments on albino mice. During the development of evident behavioural disturbances in irradiated mice (2 h after irradiation with doses 100-400 Gy), significant changes were observed in the content of phosphatidylinositides and cyclic GMP. These changes may account for disturbances in the function of the central nervous system during cerebral forms of acute radiation injury.

[The physical work capacity parameters of rodents studied by repeated high-speed swimming following uniform and nonuniform irradiation at high doses]. / Issledovanie parametrov fizicheskoi rabotosposobnosti gryzunov metodom mnogokratnogo skorostnogo plavaniia posle ravnomernogo i neravnomernogo oblucheniia v vysokikh dozakh.

Physical fitness of irradiated (20-200 Gy) mice and rats was estimated by the method of repeated swimming at a fixed distance. Revealed was the reduction adequacy of the two indices, that is the starting time and the fatigue coefficient, the latter being changed more considerably. The dose of 80-100 Gy determined the threshold of the cerebral damage and caused an irreversible decrease in the physical fitness of rodents. The role of exposure of the head in the impairment of the physical fitness of rats has been confirmed by the experiments with some body parts being shielded.

[Neuropharmacological reactivity of the body exposed to extreme factors: the effect of radiation]. / Neirofarmakologicheskaia reaktivnost' organizma pri vozdeistvii ékstremal'nykh faktorov: vliianie oblucheniia.

The functional state of neurochemical structures of male mice was investigated after their gamma-irradiation with 137Cs (1.9 Gy/min) at a dose of 100 Gy. The animals were treated with the following drugs that produce selective effects on specific receptors: galanthamine (0.5 mg/kg), amizyl (30 and 60 mg/kg), arpenal (30 mg/kg), phenamine (3, 6 and 10 mg/kg) phentolamine and obsidan (1 mg/kg), haloperidol (0.5 and 1 mg/kg), apomorphine (2 mg/kg), phenazepam (0.05 and 2 mg/kg), phenibut (200 mg/kg), and strychnin (0.1 and 0.2 mg/kg). The physical performance of the animals was measured with the aid of a swimming test applied 2 and 6 hours after irradiation. The results point to the development of heterologous desensibilization of receptors at early post-irradiation periods. The high effectiveness of agonists and antagonists of CNS transmitters in the nonirradiated animals and their low effectiveness in the irradiated animals may be considered as an indicator of post-radiation injury of specific receptors. This seems to be responsible for partial or total resistance of irradiated animals to the regulatory effects of neurotransmitters. These neuropharmacological interactions may obviously be modified in response to the combined effects of space flight factors.

[The brain phospholipids following the irradiation of animals at a high dosage]. / Fosfolipidy golovnogo mozga posle oblucheniia zhivotnykh v vysokoi doze.

In experiments with albino mice, rats and guinea pigs the effect of ionizing radiation (100 Gy) on brain phospholipids and their fatty acids has been investigated. Upon the development of manifest behavioural disturbances (2 h after irradiation) phospholipid molecules degrade insignificantly. Some changes in the relative content of phospholipids and their fatty acids are mainly found in the rat synaptosomal fraction: this may be responsible for the disturbances in the sensitivity of the receptor apparatus of cell membranes.

[The dosage thresholds for disordered physical work capacity in mice and rats following irradiation]. / Dozovye porogi narusheniia fizicheskoi rabotosposobnosti myshei i krys posle oblucheniia.

Physical efficiency of mice and rats at early times following irradiation with doses of 35 to 200 Gy was estimated by the muscle endurance and motor coordination indices. A threshold nature of the effects was exhibited at high doses. For instance, as large as 40 Gy was the dose threshold at which stability in the accomplishment of the known operations was impaired; at 70-100 Gy, the accomplishment decreased down to 50% of the initial level, by the 2nd hour after irradiation, with the subsequent partial restoration; 200 Gy was the threshold dose at which the disturbances were irreversible. These values were also similar to those of the threshold doses at which clinical picture of the affection was changed.

[Various physiological characteristics of primary radiation reaction and its apomorphine model]. / Nekotorye fiziologicheskie kharakteristiki pervichnoi luchevoi reaktsii i ee apomorfinovoi modeli.

Experiments were performed on 52 dogs exposed to irradiation at a dose of 5-80 Gy or injected with 0.02-0.5 mg/kg apomorphine. The apomorphine effect was also studied in 18 healthy male volunteers. Apomorphine injected to dogs reproduced to a certain extent the pattern and sequence of gastrointestinal, sensorimotor and circulatory lesions constituting the primary radiation reaction. The apomorphilne dosage ED50-ED90, in terms of vomiting, roughly corresponded to irradiation at a dose of 5-10 Gy. The basic difference was that the time of onset and duration of specific symptoms after irradiation were several times longer than after apomorphine injection. It is suggested that the common pathogenetic component in the primary reaction to irradiation and its apomorphine model is the phasic change in the activities of brain dopaminergic systems.