Establishment of the experimental rat model of combined injury caused by blast and liquid propellant intoxication

Objective To establish model of the blast-toxicosis combined injury caused by the explosion of the liquid propellant. Methods Three hundred and ninety-two male Wistar rats were divided randomly into 7 groups: ①blast injury group, ②unsymmetrical dimethylhydrazine(UDMH) group, ③nitrogen tetroxide(N2O4) intoxication group, ④blast injury accompanied with intoxication of UDMH group, ⑤blast injury accompanied with intoxication of N2O4 group, ⑥ blast injury accompanied with intoxication of UDMH and N2O4 group, ⑦normal controls. BST-I blast wave tube was used to induce blast injury, the excess pressure of the blast was 471.5 kPa and the positive pressure sustained for 55～60 ms. To establish the blast-toxicosis combined injury model, the UDMH 800×10-6 (800 ppm) or/and the N2O4 43×10-6 (43 ppm) were given to rats through inhalation in an intoxication tank for 15 min after the blast injury. The clinical states of experimental rats were observed, and the animals were killed sequentially 3, 6, 12, 24, 48 and 72 h after injury for blood gas analysis and biochemical examination. Results According to the clinical observation and results of blood gas analysis and biochemical examinations, the blast-toxicosis combined injury model was established successfully. It was stable, economical, practical and easy to repeat. Conclusions Injury caused by the explosion of liquid propellant can be simulated by using the blast wave tube and the intoxication tank. Establishment of the model is of great significance for the research work in this field.