[Operation steps] Choose Wistar rats weighing 170-210g, take liquid N2 O410, 15, 20 and 25μl, and pour them into different 120L poisoning cabinets. Put 4 rats in each cabinet, add 1μl of N2O4 to the cabinet every 5 minutes, and continuously inhale the poison for 30 minutes. The lung tissues were taken for pathological observation at different time points after exposure.
【Result analysis】Usually, static inhalation of the poison only injects the poison into the poison cabinet at one time, so the poison concentration often decreases progressively and affects the experimental results. The device for active inhalation of poison is complicated and the consumption of poison is large, and it is difficult for general laboratories to meet the requirements. This method uses a large dose of poison for the first time, and then multiple small doses of poison within a fixed period of time to obtain 4 stable concentrations. This method is very suitable for general laboratories to carry out experimental research on pulmonary edema, and has great practicability.