Evaluation of the Effectiveness of the Drug Indralin in the Irradiation of Small, Medium and Large Laboratory Animals with Gamma Radiation

Purpose: Evaluation of the effectiveness of the drug indralin in experiments with small, medium and large laboratory animals. Material and methods: The objects of the study were outbred male mice of the ICR (CD-1) SPF category, rabbits of the “Soviet Chinchilla” breed, mini-pigs of the Svetlogorsk breed and beagle dogs. The experimental animals were kept in conventional conditions, on standard granulated feed and tap drinking water. During the studies, the radionuclide installation GUT200M (60Co) and the installation for generating bremsstrahlung X-rays based on the pulsed linear resonance electron accelerator ILU-14 were used as radiation sources. Mice, mini-pigs and dogs were irradiated using the GUT200M (60Co) installation, rabbits – using the ILU-14 installation. The radiation dose was controlled by thermoluminescent dosimeters in the individual dosimetry support mode. The biological effect was assessed in terms of 30-day survival for mice and rabbits and 45-day survival for large laboratory animals (mini-pigs and dogs). At the first stage, the dose-effect relationship was assessed for all experimental animals, and the irradiation conditions that ensured 80-90% mortality of animals were assessed. At the second stage, the effectiveness of indralin was assessed. Results: The following estimates were obtained: LD50/30: mice – 7.9±0.2, rabbits – 9.6±0.3; LD50/45: mini-pigs – 2.7±0.2 Gy, dogs – 2.4±0.3 Gy; LD84/30: mice – 8.7±0.4 Gy, rabbits – 10.0±0.2 Gy; LD84/45: mini-pigs – 3.1±0.2 Gy, dogs – 3.2±0.2 Gy. In the experiment on mice: when irradiated at doses of 8.7 and 10.3 Gy, there were no surviving mice in the control, while when using indralin, the proportion of surviving animals was 68 % and 38 %, respectively. In the experiment on mini-pigs: in the control 9 % survived, with indralin – 75 %; for dogs: in the control 14 % survived, with indralin – 86 %. In the experiment on rabbits, the positive effect was insignificant: there were no survivors in the control, while when using indralin at a dose of 21 mg/kg, the proportion of survivors was 15 %, and at a dose of 37.5 mg/kg – 25 %. Conclusion: In an experiment on small, medium and large laboratory animals, the high efficiency of the drug indralin was confirmed when used in regulated doses 10–15 minutes before irradiation.