[Neuropharmacological reactivity of the body exposed to extreme factors: the effect of radiation].

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.